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Infectious Diseases in Halton 2015 Annual Infectious Disease Report The Regional Municipality of Halton July 2016 Reference: Halton Region Health Department, Infectious Disease Report. Oakville, Ontario, July 2016. Author: Carley Aubin, Epidemiologist, Halton Region Health Department Megan Hempel, Epidemiologist, Halton Region Health Department Acknowledgements: Melanie Reffell, Acting Manager Sexual Health and Needle Exchange, Halton Region Health Department Kathy Jovanovic, Manager Communicable Disease Control, Halton Region Health Department Dimitra Kasimos, Manager Enteric and Vector-borne Disease, Halton Region Health Department Emma Tucker, Manager and Senior Epidemiologist, Halton Region Health Department Kristen Wheeler, Epidemiologist, Halton Region Health Department Sarah Ahmed, Data Analyst, Halton Region Health Department Table of Contents Executive Summary ................................................................................................................. 1 Introduction .............................................................................................................................. 3 Presentation of the results .................................................................................................................... 3 Part I: Leading reportable infectious diseases in 2015 in Halton ......................................... 5 Comparison with Ontario: age-standardized incidence ratios for 2015 ........................................... 7 Part II: Categories of infectious diseases .............................................................................. 8 Vaccine-preventable diseases............................................................................................................... 8 Influenza ______________________________________________________________________ 10 Streptococcus pneumoniae _______________________________________________________ 13 Pertussis (whooping cough) _______________________________________________________ 14 Chickenpox (varicella) ___________________________________________________________ 15 Hepatitis B ____________________________________________________________________ 15 Mumps _______________________________________________________________________ 16 Measles ______________________________________________________________________ 16 Invasive meningococcal disease ___________________________________________________ 16 Invasive haemophilus influenzae b disease ___________________________________________ 17 Tetanus _______________________________________________________________________ 17 Rubella _______________________________________________________________________ 17 Diphtheria _____________________________________________________________________ 18 Polio _________________________________________________________________________ 18 Smallpox ______________________________________________________________________ 18 Food- and water-borne diseases......................................................................................................... 19 Salmonellosis __________________________________________________________________ 20 Campylobacter enteritis __________________________________________________________ 21 Giardiasis _____________________________________________________________________ 22 Amebiasis _____________________________________________________________________ 23 Cyclosporiasis _________________________________________________________________ 24 Yersiniosis ____________________________________________________________________ 25 Verotoxin-producing E. coli with haemolytic uraemic syndrome ___________________________ 25 Cryptosporidiosis _______________________________________________________________ 26 Legionellosis ___________________________________________________________________ 26 Shigellosis ____________________________________________________________________ 27 Listeriosis _____________________________________________________________________ 27 Typhoid fever __________________________________________________________________ 27 Hepatitis A ____________________________________________________________________ 28 Paratyphoid fever _______________________________________________________________ 28 Botulism ______________________________________________________________________ 28 Cholera _______________________________________________________________________ 29 Trichinosis ____________________________________________________________________ 29 Paralytic shellfish poisoning _______________________________________________________ 29 Sexually-transmitted and blood-borne infections ............................................................................. 30 Chlamydial infections ____________________________________________________________ 31 Gonorrhoea ___________________________________________________________________ 33 Hepatitis C ____________________________________________________________________ 35 Syphilis _______________________________________________________________________ 36 HIV and AIDS __________________________________________________________________ 37 Chancroid _____________________________________________________________________ 38 Neonatal infectious diseases .............................................................................................................. 39 Neonatal group B streptococcal disease _____________________________________________ 39 Early congenital syphilis __________________________________________________________ 39 Congenital rubella syndrome ______________________________________________________ 39 Opthalmia neonatorum ___________________________________________________________ 40 2015 Halton Region Infectious Disease Report Zoonotic, vector-borne & exotic diseases ......................................................................................... 41 Lyme disease __________________________________________________________________ 42 Malaria _______________________________________________________________________ 43 West Nile virus illness____________________________________________________________ 43 Q fever _______________________________________________________________________ 43 Brucellosis ____________________________________________________________________ 44 Leprosy _______________________________________________________________________ 44 Hemorrhagic fevers _____________________________________________________________ 44 Tularemia _____________________________________________________________________ 45 Yellow fever ___________________________________________________________________ 45 Rabies _______________________________________________________________________ 45 Psittacosis/ornithosis ____________________________________________________________ 46 Anthrax _______________________________________________________________________ 46 Lassa fever ____________________________________________________________________ 46 Hantavirus pulmonary syndrome ___________________________________________________ 47 Plague _______________________________________________________________________ 47 Other reportable infectious diseases ................................................................................................. 48 Encephalitis and meningitis _______________________________________________________ 49 Invasive group A streptococcal disease ______________________________________________ 50 Tuberculosis ___________________________________________________________________ 51 Acute flaccid paralysis ___________________________________________________________ 52 Creutzfeldt-Jakob disease ________________________________________________________ 52 Severe Acute Respiratory Syndrome ________________________________________________ 52 Part III: Infectious diseases and the social determinants of health .....................................53 Part IV: Outbreak investigations ............................................................................................55 Respiratory outbreaks .......................................................................................................................... 56 Agent ________________________________________________________________________ 56 Location ______________________________________________________________________ 56 Seasonal variation ______________________________________________________________ 57 Outbreak duration _______________________________________________________________ 57 Number of cases investigated _____________________________________________________ 58 Enteric outbreaks ................................................................................................................................. 58 Agent ________________________________________________________________________ 58 Location ______________________________________________________________________ 59 Seasonal variation ______________________________________________________________ 59 Outbreak duration _______________________________________________________________ 60 Number of cases investigated _____________________________________________________ 60 Conclusion ..............................................................................................................................61 References ..............................................................................................................................62 Appendix A: O. Reg 559/91 under the Health Protection and Promotion Act .....................63 Appendix B: Data notes and limitations ................................................................................65 Definitions ............................................................................................................................................. 65 Data Sources ......................................................................................................................................... 65 iPHIS data extraction logic .................................................................................................................. 66 Limitations ............................................................................................................................................. 66 Appendix C: Summary table of case definitions ..................................................................68 Appendix D: Summary of counts and rates of reportable infectious diseases ..................70 2015 Halton Region Infectious Disease Report List of Figures Figure 1: Top 10 most frequently reported infectious diseases in Halton residents 2010-2015... 6 Figure 2: Age-standardized incidence ratio for the top ten most frequently reported infectious diseases, Halton and Ontario, 2015. .......................................................................................... 7 Figure 3: Most frequently reported vaccine-preventable diseases compared to previous five-year average, Halton residents, 2010-2015. ...................................................................................... 9 Figure 4: Influenza crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015 (calendar year). .....................................................................10 Figure 5: Influenza age-specific incidence rates (per 100,000), by sex, Halton residents, 2015 (calendar year). .........................................................................................................................11 Figure 6: Influenza cases, by surveillance week and influenza season, Halton residents, 20102015..........................................................................................................................................12 Figure 7: Streptococcus pneumoniae crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015. ...................................................13 Figure 8: Pertussis crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015. .............................................................................................14 Figure 9: Most frequently reported food- and water-borne diseases compared to previous fiveyear average, Halton residents, 2010-2015...............................................................................19 Figure 10: Salmonellosis crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015. ..............................................................................20 Figure 11: Campylobacter enteritis crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015. ...................................................................21 Figure 12: Giardiasis crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015. ..............................................................................22 Figure 13: Amebiasis crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015. ..............................................................................23 Figure 14: Cyclosporiasis crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015. ..............................................................................24 Figure 15: Yersiniosis crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015. ..............................................................................25 Figure 16: Most frequently reported sexually-transmitted and blood-borne infections in Halton compared to previous five-year average, Halton residents, 2010-2015. ....................................30 Figure 17: Chlamydia crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015. ..............................................................................31 Figure 18: Chlamydia age-specific incidence rates (per 100,000), by sex, Halton residents, 2015..........................................................................................................................................32 Figure 19: Gonorrhoea crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015. ..............................................................................33 Figure 20: Gonorrhoea age-specific incidence rates (per 100,000), by sex, Halton residents, 2015..........................................................................................................................................34 Figure 21: Hepatitis C crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015. ..............................................................................35 Figure 22: Other syphilis* crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015. ..............................................................................36 Figure 23: HIV crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015. .............................................................................................37 Figure 24: Most frequently reported zoonotic and exotic infections in Halton compared to previous five-year average, Halton residents, 2010-2015. .........................................................41 Figure 25: Lyme disease crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015. ..............................................................................42 2015 Halton Region Infectious Disease Report Figure 26: Other reportable diseases compared to previous five-year average, Halton residents, 2015 and 2010-2014. ................................................................................................................48 Figure 27: Encephalitis and meningitis combined* crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015. ............................................49 Figure 28: Invasive Group A streptococcal disease crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015. ............................................50 Figure 29: Tuberculosis crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015. ..............................................................................51 Figure 30: Age-standardized incidence rate (per 100,000), by neighbourhood income group, Halton Region, 2015 .................................................................................................................54 Figure 31: Respiratory outbreaks investigated in Halton compared to previous five-year average, by agent, 2015 and 2010-2014. ..................................................................................56 Figure 32: Respiratory outbreaks investigated in Halton, by location, 2015. ..............................56 Figure 33: Respiratory outbreaks investigated in Halton, by month of onset, 2015. ...................57 Figure 34: Respiratory outbreaks investigated in Halton, by duration, 2015. .............................57 Figure 35: Enteric outbreaks investigated in Halton compared to previous five-year average, by agent, 2015 and 2010-2014. .....................................................................................................58 Figure 36: Enteric outbreaks investigated in Halton compared previous five-year average, by location, 2015 and 2010-2014. ..................................................................................................59 Figure 37: Enteric outbreaks investigated in Halton, by month of onset, 2015. ..........................59 Figure 38: Enteric outbreaks investigated in Halton, by duration, 2015. ....................................60 List of Tables Table 1: Number, crude rate, and age-standardized rate of the top ten most frequently reported infectious diseases in Halton residents, 2015 ............................................................................. 5 Table 2: Total number of clients and staff who were at risk and who were ill, by location of the outbreak, respiratory outbreaks, Halton Region, 2015...............................................................58 Table 3: Total number of clients and staff who were at risk and who were ill, by location of the outbreak, enteric outbreaks, Halton Region, 2015 .....................................................................60 Table 4: Summary table of provincial case definitions, adapted from the 2015 Infectious Disease Protocol (Appendix B)3 ..............................................................................................................68 Table 5: Summary of counts, crude rates, crude rate ratio, age-standardized rates, and agestandardized rate ratio for reportable infectious diseases, Halton and Ontario, 2010-2015. ......70 Table 6: Summary of counts of rare reportable diseases in Halton, 2010-2015 .........................73 2015 Halton Region Infectious Disease Report Executive Summary The Halton Region Health Department (HRHD) works towards the goal of reducing the incidence of infectious diseases in the community through a variety of programs and services, including investigating individual cases and responding to outbreaks, inspecting retail food services and personal service settings, health promotion campaigns, and providing immunizations and other clinical services. Reportable infectious diseases in Halton Reportable infectious diseases are diseases that are required under the Health Protection and Promotion Act1 to be reported to the local Medical Officer of Health. In 2015, 2081 cases of reportable infectious diseases were reported to the Halton Region Health Department. The top five most common reportable infectious diseases in Halton in 2015 were: Chlamydial infections Influenza Campylobacter enteritis Salmonellosis Gonorrhoea Vaccine-preventable diseases are diseases for which an effective vaccine exists. In 2015, 451 Halton residents were diagnosed with a vaccine-preventable disease, accounting for 22% of all reportable diseases this past year. Age-standardized rates of vaccine-preventable diseases in 2015 were similar or lower in Halton compared to Ontario. The most commonly reported vaccine-preventable disease was influenza (398 cases). The true number of influenza cases in the population is likely to be much higher, however, as many people may not seek medical treatment or receive laboratory testing for influenza and therefore cases are not reported. Food- and water-borne diseases are caused by bacteria, parasites and viruses that have found their way into food or water that is being consumed. In 2015, there were 376 reported cases of food and water-borne diseases among Halton residents, accounting for 18% of the total cases of reportable infectious diseases this past year. The most commonly reported foodand water-borne diseases in 2015 were salmonellosis (123 cases) and Campylobacter enteritis (123 cases). Age-standardized rates of food- and water-borne diseases in Halton were similar or lower compared to Ontario. Higher rates of cyclosporiasis in Halton and Ontario in 2015 were likely related to a national outbreak of cyclosporiasis that occurred in the summer of 2015. In 2015, 41% of food- and water-borne illnesses in Halton were associated with travel outside of Canada. Sexually-transmitted and blood-borne infections are the most common category of reportable infectious diseases in Halton. In 2015, there were 1171 reported sexually-transmitted infections (STI) and blood-borne infections among Halton residents, accounting for over half of all reportable diseases in Halton. Chlamydia is the most commonly reported infectious disease in Halton (916 cases). Other common STIs and blood-borne infections include gonorrhoea (117 cases) and Hepatitis C (99 cases). In general, rates of STIs and blood-borne infections are lower in Halton compared to Ontario. In recent years, Halton has seen an increase in reported cases of gonorrhoea and chlamydia, which reflects the overall trend in Ontario. 2015 Halton Region Infectious Disease Report 1 Reportable neonatal infectious diseases are transferred from mother to infant either through the placenta, or through the birth canal at the time of birth. In 2015, there were three cases of reportable neonatal diseases. Zoonotic diseases are diseases that can be passed between humans and animals. Vectorborne diseases are spread to people by small organisms such as mosquitoes and ticks. In 2015, there were 16 zoonotic or vector-borne diseases reported in Halton, accounting for less than 1% of all reportable diseases. The most commonly reported vector-borne disease was Lyme disease (10 cases). Halton only experienced 1 reported case of West Nile virus illness in 2015, which was lower than the previous 5 year average. There were an additional 64 cases of other reportable diseases (meningitis/encephalitis, group A streptococcal disease, tuberculosis) reported to the Halton Region Health Department in 2015, accounting for 3% of all reportable diseases in Halton. Rates of tuberculosis in Halton in 2015 were significantly lower than Ontario. Infectious diseases and the social determinants of health Social determinants of health reflect the social and physical conditions where people live, learn, work, and play. Due to the influence of the social determinants of health, the burden of infectious disease is not evenly distributed across the population. In 2015, the rate of reportable infectious diseases in Halton increased as neighbourhood income decreased. Outbreak investigations HRHD staff investigate outbreaks in order to decrease or eliminate health risks presented by infectious diseases. All institutional enteric and respiratory outbreaks are reportable to the HRHD, regardless of whether or not the specific disease is known or reportable. In 2015, there were 74 confirmed and suspect respiratory outbreaks investigated by the HRHD. The majority of respiratory outbreaks investigated by the HRHD involved long-term care homes (69%), followed by retirement residences (22%), unregulated/special homes (5%), hospital (3%), and child care centres (1%). The most common agent was influenza A (45%), followed by rhinovirus (23%). Respiratory outbreaks occurred most commonly in the winter months, particularly January. In 2015, there were 56 confirmed enteric outbreaks investigated by the HRHD. The majority of enteric outbreaks investigated by the HRHD occurred in child care centres (55%), followed by long-term care homes (27%), retirement residences (13%), the community (4%), and hospitals (2%). Over half the agents involved in enteric outbreaks were unknown, but the most common known agent was norovirus (32%). Enteric outbreaks occurred most frequently in the late winter months (February and March). 2015 Halton Region Infectious Disease Report 2 Introduction The 2015 Halton Region Infectious Disease Report summarizes the incidence of infectious diseases that were reported to the Health Department for Halton Region residents in 2015. These diseases are caused by a variety of organisms including bacteria, viruses, and protozoa, or through toxins from these organisms. Infectious diseases are spread from one host to another by close personal contact, sexual contact, contaminated food or water, animals, or other environmental sources. The current list of infectious diseases that must be reported to the local Medical Officer of Health under the Health Protection and Promotion Act (HPPA)1 is shown in Appendix A: O. Reg 559/91 under the Health Protection and Promotion Act. Under the Health Protection and Promotion Act, outbreaks in any institutions of any infectious diseases must also be reported. The 2015 Halton Region Infectious Disease Report reflects the surveillance and health status reporting function that the Health Department is mandated to perform in order to monitor the impact of infectious disease programs and to identify significant or emerging issues. The Health Department works towards the goal of reducing the incidence of infectious diseases in the community through the delivery of various programs. Staff investigate reports of individual cases and respond to outbreaks in both the community and in institutions such as long-term care homes, retirement homes, acute care settings, child care settings, schools, colleges, and correctional institutions. In addition to investigating disease reports and preventing further spread of disease, the Health Department also conducts inspections of licensed child care settings, personal service settings, food premises, small drinking water systems, and public spas and swimming pools. Finally, the Health Department is mandated to provide education and certification programs, such as food handler training, as well as clinical services, such as immunization and sexual health clinics, which help to prevent and reduce the burden of infectious diseases. Presentation of the results This report is divided into four different sections: Part I: Leading reportable infectious diseases in 2015 in Halton provides an overview of the top ten most commonly reported infectious diseases in Halton. Part II: Categories of infectious diseases provides an in-depth look at the counts and rates of each reportable disease under the HPPA2 in Halton compared to Ontario. Trends over time are presented in graphs for diseases with 10 or more cases in 2015. Age and sex distributions are also presented for the most common reportable infectious diseases in Halton. Part III: Infectious diseases and the social determinants of health examines the relationship between income and the incidence of reportable infectious diseases in Halton in 2015. Part IV: Outbreak investigations presents a summary of respiratory and enteric outbreak investigations conducted by the HRHD in 2015. 2015 Halton Region Infectious Disease Report 3 Infectious disease data are presented as counts, crude rates, age-standardized rates, and agespecific rates: Crude incidence rates are used to get an actual depiction of the incidence of infectious diseases in Halton. It should not be used to directly compare two different populations (such as Halton and Ontario), as crude rates are influenced by the age structure of a population. Age-standardized incidence rates are used to compare the different populations of Halton and Ontario, as well as neighbourhood income groups. The rates are standardized to the 1991 Canadian population. This ensures that any differences in rate between populations are not due to differences in the age distributions between populations. Age-standardized rates provide an overall rate for all ages combined. Age-specific rates are used to make comparisons between age groups in Halton. Agespecific rates allow for comparisons by age group and sex to determine if certain age groups are more likely than others to have particular infectious diseases. Age-specific rates are presented for the most common reportable infectious diseases in Halton. Trends over time were tested for significance using linear regression and adjusting for autocorrelation. Please note that the upper limit of the Y-axis scale used in each graph differs. The data presented in this report are from the Integrated Public Health Information System (iPHIS). iPHIS is a dynamic disease reporting system which allows ongoing updates to data previously entered. As a result, data extracted from iPHIS represent a snapshot at the time of extraction and may differ from previous or subsequent reports. For more information on limitations of this report, as well as data extraction logic, see Appendix B: Data notes and limitations. The Provincial Case Definitions3 from the Infectious Disease Protocol, 2015 were used to determine what was considered a “case”. For certain diseases, only confirmed cases are counted, whereas others include probable and/or suspect cases as well. For a summary table of the case definitions used in this report, see Appendix C: Summary table of case definitions. Descriptions of each reportable disease were adapted from the Disease Specific Chapters4 of the Infectious Disease Protocol, 2015. When interpreting trends over time, it is important to consider changes to case definitions and laboratory testing. For example, Ontario adopted new case definitions for all reportable diseases in April 2009 and additional updates to case definitions for certain disease have occurred in subsequent years. Therefore comparisons of data before and after April 2009, as well as any additional years where definitions have changed, should be interpreted with caution. Only cases of diseases that were reported to the health department are captured in this report. Individuals who do not experience any symptoms or only experience mild symptoms may not seek medical attention or may not be tested for a specific disease, and would not be captured in this report. This report therefore likely underestimates the true rates of infectious diseases in the population, especially for common, milder illnesses such as many food- and water-borne infections. 2015 Halton Region Infectious Disease Report 4 Part I: Leading reportable infectious diseases in 2015 in Halton In 2015, 2,081 cases of reportable infectious diseases were reported to the Halton Region Health Department (HRHD). Table 1 shows the 10 most frequently reported infectious diseases which accounted for 91% of the total cases. Figure 1 shows the number of cases of these diseases in 2015 compared to the previous five-year annual average. For a summary of the counts, crude rates, and age-standardized rates of reportable diseases in Halton, including comparisons to previous years, see Appendix D: Summary of counts and rates of reportable infectious diseases. Table 1: Number, crude rate, and age-standardized rate of the top ten most frequently reported infectious diseases in Halton residents, 2015 Crude Incidence Rate per 100,000 Age-Standardized Incidence Rate per 100,000 916 163 203 Influenza (calendar year) Campylobacter enteritis 398 71 61 123 22 22 Salmonellosis 123 22 23 Gonorrhoea 117 21 26 Hepatitis C 99 18 19 Giardiasis 46 8.2 8.7 Encephalitis/meningitis* 35 6.2 6.7 Syphilis** 27 4.8 5.3 25 4.5 4.8 Total Number of Reported Confirmed Cases of the top 10 diseases 1903 --- --- All Other Reported Cases 178 --- --- Total number of reported cases in 2015 2081 --- --- Total Reported Confirmed Cases Chlamydial Infections Amebiasis Source: Integrated Public Health Information System [2012-2015], extracted April 20, 2016; Population Estimates, IntelliHEALTH, Ontario Ministry of Health and Long-Term Care [2013], extracted March 21, 2015. *Includes primary viral and unspecified encephalitis; encephalitis/meningitis; bacterial, other, and viral meningitis **Excludes early congenital syphilis 2015 Halton Region Infectious Disease Report 5 Figure 1: Top 10 most frequently reported infectious diseases in Halton residents 20102015 Source: Integrated Public Health Information System [2012-2015], extracted April 20, 2016 *Includes primary viral and unspecified encephalitis; encephalitis/meningitis; bacterial, other, and viral meningitis **Excludes early congenital syphilis 2015 Halton Region Infectious Disease Report 6 Comparison with Ontario: age-standardized incidence ratios for 2015 Figure 2 shows the incidence ratio for the top 10 infectious disease in Halton in 2015 compared to Ontario. If the confidence intervals (CIs) fall completely to the left of the line, it indicates that Halton’s rate was statistically significantly lower than Ontario’s rate. If the CI falls completely to the right of the line it means Halton’s rate was statistically significantly higher than Ontario’s rate. If the incidence ratio or corresponding CIs touch the line, then there was no statistically significant difference between Halton and Ontario. As seen in Figure 2, Halton had statistically significantly lower age-standardized rates of chlamydia, gonorrhoea, hepatitis C, and syphilis compared to Ontario. There were no statistically significant differences between Halton and Ontario in the age-standardized rate of any of the remaining top ten most frequently reported infectious diseases in Halton. For a comparison of rates and incidence ratios for common reportable diseases for Halton and Ontario, see Appendix D: Summary of counts and rates of reportable infectious diseases. Figure 2: Age-standardized incidence ratios for the top ten most frequently reported infectious diseases, Halton and Ontario, 2015. Sources: Integrated Public Health Information System [2015], extracted April 20, 2016; Population Estimates, IntelliHEALTH, Ontario Ministry of Health and Long-Term Care [2015], extracted March 21, 2015. Ontario data: Ontario Ministry of Health and LongTerm Care, Integrated Public Health System database, extracted by Public Health Ontario [January 22, 2016]. *Includes primary viral and unspecified encephalitis; encephalitis/meningitis; bacterial, other, and viral meningitis **Excludes early congenital syphilis 2015 Halton Region Infectious Disease Report 7 Part II: Categories of infectious diseases Vaccine-preventable diseases This section provides an overview of vaccine-preventable diseases reported to the HRHD in 2015. Vaccine-preventable diseases (VPDs) are diseases for which an effective vaccine exists. For the purposes of this report, there are 14 reportable diseases that are considered vaccinepreventable because they are part of Ontario’s routine immunization program, publically funded (influenza), or have been eradicated through vaccination (smallpox). Vaccines have played a key role in reducing the burden of many diseases and have even eradicated (i.e. world-wide) or eliminated (i.e. continent-wide) some diseases that in the past century have caused major illnesses and loss of life. Illnesses from nine infectious diseases (smallpox, diphtheria, pertussis, tetanus, polio, measles, mumps, rubella and H. influenzae type B) have decreased substantially or been eliminated entirely in North America. By age six, Ontario children have received immunization against 12 diseases. Under the Child Care and Early Years Act, children attending childcare settings are required to provide proof of age-appropriate immunization (unless exempt) against: Diphtheria, tetanus, pertussis, polio, Haemophilus influenzae B disease, measles, mumps, rubella, meningococcal disease, pneumococcal disease, and varicella (chickenpox). Rotavirus and influenza are recommended but not required. Under the Immunization of School Pupils Act, children attending school are required to provide proof of age-appropriate immunization (unless exempt) against: Diphtheria, tetanus, pertussis, polio, measles, mumps, rubella, meningococcal disease, and varicella if born in 2010 or later. Influenza is recommended but not required. For more information on publicly funded vaccines and the routine immunization schedule, see the Publicly Funded Immunization Schedules for Ontario.5 5 Because vaccines have different levels of effectiveness and/or do not cover all strains or subtypes of the organisms at which they are aimed, not all vaccines are equally effective. Also, coverage of the population is not 100%. This is why it is important to monitor the incidence of vaccine-preventable diseases. 2015 Halton Region Infectious Disease Report 8 In 2015, 451 Halton residents were diagnosed with VPDs, accounting for 22% of the total cases of reportable infectious diseases that year. Figure 3 shows the number of cases of VPDs in Halton residents in 2015 compared to the previous five-year averages. There were no cases of invasive meningococcal disease, invasive Haemophilis influenzae B disease, tetanus, diphtheria, polio, rubella or smallpox reported to the HRHD in 2015. Figure 3: Most frequently reported vaccine-preventable diseases compared to previous five-year average, Halton residents, 2010-2015. Sources: Integrated Public Health Information System [2015], extracted April 20, 2016 2015 Halton Region Infectious Disease Report 9 Influenza For the 2015 calendar year there were 398 reported cases of influenza, accounting for 88% of the reportable vaccine-preventable diseases and 19% of all reportable diseases. Influenza is a highly infectious respiratory illness caused by one of the three types of influenza virus: A, B, or C. Influenza A and B are of higher public health importance as they are responsible for epidemics. In contrast to the common cold, symptoms of influenza are more sudden in onset and more severe (fever, sore throat, headache, muscle ache, profound fatigue, cough), especially in very young, old, or individuals with compromised immune systems. In children, nausea, vomiting and diarrhea are not uncommon. Symptoms usually resolve in five to seven days, however complications such as pneumonia may develop. Many cases of influenza are not diagnosed or reported to the Halton Region Health Department because infected individuals often do not seek medical attention or, when doctors are visited physicians often do not order laboratory confirmation because it is unnecessary in uncomplicated situations when influenza is known to be circulating. Monitoring influenza is important due to how quickly epidemics evolve, the widespread morbidity, and the seriousness of complications, notably viral and bacterial pneumonias. Halton age-standardized influenza incidence rates by calendar year have been similar to those of the province (Figure 4). The impact of influenza as well as the rate of clinical testing are highly variable and therefore annual fluctuations above or below the provincial average are not surprising. The number of laboratory-confirmed cases of influenza can be helpful for tracking the timing and severity of the influenza season. However the actual number of cases is largely underestimated as a large proportion of infected persons would not receive laboratory testing. Figure 4: Influenza crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015 (calendar year). Sources: Integrated Public Health Information System [2006-2015], extracted April 20, 2016; Population Estimates, IntelliHEALTH, Ontario Ministry of Health and Long-Term Care [2015], extracted March 21, 2015. Ontario data: Ontario Ministry of Health and Long-Term Care, Integrated Public Health System database, extracted by Public Health Ontario [January 22, 2016]. 2015 Halton Region Infectious Disease Report 10 In 2015, the age-specific rate of influenza in Halton was highest among those ages 70 and over (Figure 5). In general rates of influenza were similar for males and females. Females over the age of 70 had a slightly higher age-specific rate of influenza compared to males, however this difference was not statistically significant. It is important to keep in mind that reported cases of influenza may not represent the true age distribution of influenza cases in the population. It is possible that older adults and young children may be more likely to be tested for influenza. For example, older adults or young children may be more likely to have severe cases, to seek medical attention, and for the case to consequently be tested, diagnosed and reported. Testing for influenza cases may also be higher among residents of retirement homes and long-term care facilities compared to the general population. Figure 5: Influenza age-specific incidence rates (per 100,000), by sex, Halton residents, 2015 (calendar year). Sources: Integrated Public Health Information System [2006-2015], extracted April 20, 2016; Population Estimates, IntelliHEALTH, Ontario Ministry of Health and Long-Term Care [2015], extracted March 21, 2015. 2015 Halton Region Infectious Disease Report 11 In countries with temperate climates, influenza activity peaks during the winter months. In Canada, influenza season typically runs from November to April. Figure 6 shows counts of reported cases of influenza by surveillance week for the past five influenza seasons in Halton. The amount of influenza activity and the peak of influenza activity varied in Halton each year. The 2014/15 influenza season in had a higher volume of influenza activity compared to previous influenza seasons. Figure 6: Influenza cases, by surveillance week and influenza season, Halton residents, 2010-2015. Sources: Integrated Public Health Information System [2006-2015], extracted April 20, 2016; *The 2014-15 influenza season included a week 53 (December 28, 2014 to January 3, 2015). A week 53 occurs once every five to six years. 2015 Halton Region Infectious Disease Report 12 Streptococcus pneumoniae In 2015, there were 20 reported cases of invasive Streptococcus pneumoniae (invasive pneumococcal disease), accounting for 4% of the reportable vaccine-preventable diseases, and 1% of all reportable diseases. Streptococcus pneumoniae is a bacterial infection that occurs most frequently in infants, young children and the elderly. Symptoms include high fever, headache, lethargy, vomiting, and irritability, and in serious cases seizures and meningitis. The disease can occur throughout the year, but is most common in the winter and spring. The pneumococcal conjugate (Pneu-C-13) vaccine is given at 2 months, 4 months and 12 months. As seen in Figure 7, the age-standardized incidence rates of Streptococcus pneumoniae in Halton were quite variable in the past, as would be expected because of the relatively small numbers, but on the whole have been decreasing since 2010. In Ontario, the age-standardized rate of Streptococcus pneumoniae increased slightly from 2006 until 2010, and then began to decrease. In 2015, the Halton age-standardized incidence rate for Streptococcus pneumoniae was statistically significantly lower than Ontario. Figure 7: Streptococcus pneumoniae crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015. Sources: Integrated Public Health Information System [2006-2015], extracted April 20, 2016; Population Estimates, IntelliHEALTH, Ontario Ministry of Health and Long-Term Care [2015], extracted March 21, 2015. Ontario data: Ontario Ministry of Health and Long-Term Care, Integrated Public Health System database, extracted by Public Health Ontario [January 22, 2016]. 2015 Halton Region Infectious Disease Report 13 Pertussis (whooping cough) In 2015, there were 13 reported cases of pertussis (whooping cough), accounting for 3% of the reportable vaccine-preventable diseases and less than 1% of all reportable diseases. Pertussis is a bacterial infection that begins with a mild upper respiratory cough that can last one to two weeks, before progressing to a more frequent and severe cough. The cough (which often sounds like a whoop) is often followed by vomiting, and can last for one to two months. During recovery the cough gradually disappears, but can take several weeks to months. Young infants are at the highest risk and often have the most serious complications. Children receive vaccinations against pertussis at two, four, six, and 18 months, between four to six years, and again between 14 and 16 years. Adults should receive one dose of pertussis containing vaccine every 10 years after their adolescent dose. Receiving the two, four, and six month doses of the pertussis vaccine is most critical to reduce infant mortality and hospitalizations associated with pertussis. As seen in Figure 8, the age-standardized incidence rates of pertussis in Halton and Ontario have declined between 2006 and 2010, and have remained fairly constant in Halton since 2012. The peak in pertussis cases in 2012 in Ontario was due to an outbreak beginning in an underimmunized religious community in southwestern Ontario.6 6 In 2015, the age-standardized incidence rate of pertussis was statistically significantly lower in Halton compared to Ontario. Nearly 1/3 of pertussis cases in Halton occurred in infants under one year old. Figure 8: Pertussis crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015. Sources: Integrated Public Health Information System [2006-2015], extracted April 20, 2016; Population Estimates, IntelliHEALTH, Ontario Ministry of Health and Long-Term Care [2015], extracted March 21, 2015. Ontario data: Ontario Ministry of Health and Long-Term Care, Integrated Public Health System database, extracted by Public Health Ontario [January 22, 2016]. 2015 Halton Region Infectious Disease Report 14 Chickenpox (varicella) In 2015, there were 11 reported cases of chickenpox, accounting for approximately 2% of the reportable vaccine-preventable diseases and less than 1% of all reportable diseases. Chickenpox, or varicella, is an acute, generalized viral disease with sudden onset of slight fever, and a rash that begins as red spots, followed by small blisters for 3 to 4 days, and then scabs that may leave small scars. This viral infection remains latent and the disease may recur years later as herpes zoster (shingles) in about 15% of older adults, and sometimes in children. The one-dose varicella immunization program was introduced in Ontario in 2004 and was added to the children’s immunization schedule. The program was expanded in August 2011 to include a second dose to reduce breakthrough infections from waning immunity in individuals who previously received a single dose. As of January 2005, the first year for which case-specific data was available, individual laboratory-confirmed reports or those cases resulting in complications or hospitalization were reportable to the Health Department. In addition, all cases of chickenpox should be reported as aggregate. Cases that run their course of illness at home, however, are often not reported to the Halton Region Health Department. Also, physicians may make a clinical diagnosis of the disease and may not report it to the health department. Therefore caution must be taken when interpreting data as it is subject to significant underreporting. A comparison to Ontario is not available for chickenpox, as Public Health Ontario chose to exclude chickenpox data from the Infectious Disease Query due to the fact that chickenpox is not reliably reported. The limitations of chickenpox reporting have been recognized, and in 2016 the province made revisions to the varicella standards in the Ontario Public Health Standards to improve aggregate data reporting. This revision will also expand case and contact management for all laboratory confirmed cases. Hepatitis B In 2015, there were six reported cases of hepatitis B virus, accounting for approximately 1% of vaccine-preventable diseases in Halton. There was no statistically significant difference between Halton and Ontario in the age-standardized rate of hepatitis B infection in 2015. Most people with acute hepatitis B virus don’t experience symptoms, and those that do experience symptoms similar to hepatitis C infection, including loss of appetite, fatigue, abdominal pain, and fever, as well as jaundice. In rare cases, the active infection can rapidly (within hours or days) develop into severe liver failure which may result in death. Hepatitis B infection is classified as chronic when the infection lasts longer than six months. Hepatitis B infection is one of the leading causes of liver cancer worldwide. Important routes of hepatitis B transmission include sexual contact, sharing of personal items such as razors with an infected individual, mother-to-infant transmission, injection drug use, and exposure to contaminated medical equipment. The hepatitis B vaccine is very effective at reducing the risk of hepatitis B infection. Ontario’s universal vaccination program provides the hepatitis B vaccine to students in grade 7. 2015 Halton Region Infectious Disease Report 15 Mumps In 2015, there were two cases of mumps reported among Halton residents, and 33 cases in all of Ontario. Mumps is a viral infection. Symptoms of mumps include fever, and swelling/tenderness of one or more salivary glands. Inflammation of the parotid gland may also occur, as well as nonspecific respiratory symptoms. Mumps may result in testicular inflammation in males and ovarian inflammation in female, which in rare cases can lead to fertility issues. Mumps infection in the first trimester of pregnancy may result in fetal loss. The measles, mumps and rubella (MMR) vaccine is given to children at 12 months, and again between the ages of four and six. Proof of vaccination is required for all children over the age of six to attend school in Ontario, unless exemption has been given. Measles In 2015, there was one case of measles reported among Halton residents, and 21 cases in all of Ontario. Measles is a disease caused by the measles virus. Measles has essentially been eliminated in Canada due to mandatory vaccination, however travel-related cases, or outbreaks among unvaccinated communities may still occur. Measles begins with a fever, runny nose, cough, drowsiness, and irritable red eyes. Small white spots may appear in the mouth, and the characteristic red, blotchy rash appears on the face and progresses down the body about 3-7 days after the onset of symptoms. Measles complications are the most severe in those with malnutrition, immunodeficiency and pregnant women. Exposure to measles while pregnant can cause premature labour or miscarriage. The measles, mumps and rubella (MMR) vaccine is given to children at 12 months, and again between the ages of four and 6. Proof of vaccination is required for all children over the age of six to attend school in Ontario, unless exemption has been given. Invasive meningococcal disease There were no reported cases of invasive meningococcal diseases in Halton in 2015, and 34 cases in all of Ontario. Over the previous 5 years (2010-2014), there were a total of 4 reported cases in Halton. Invasive meningococcal disease is caused by the bacteria Neisseria meningitides. Invasive meningococcal disease presents most commonly as either meningitis or meningococcemia (meningococcal sepsis or bloodstream infection). Invasive meningococcal disease has a case fatality between 8-15%, and many that survive the disease have long-term complications such as hearing loss, mental impairment, loss of limbs or use of limbs, and scarring. Symptoms typically appear within three to four days of exposure to the bacteria. About 10% of the population carries the bacteria that causes invasive meningococcal disease, but may not have any symptoms. These individuals can spread the bacteria as long as they are present in their body. The bacteria are spread through direct contact with nose and throat secretions of people infected with the bacteria, and through saliva. People who have close 2015 Halton Region Infectious Disease Report 16 contact with an individual with invasive meningococcal disease can be given antimicrobial chemoprophylaxis within 24 hours to reduce their risk of developing the disease. Immunization against meningococcal disease is available as part of the Publicly Funded Immunization Schedules for Ontario, and is required for all children attending school in Ontario, unless exempt. The Men-C-C vaccine is given to children at 12 months old, and the Men-CACYW vaccine is given in grade 7. Invasive Haemophilus influenzae b disease In 2015, there were no reported cases of invasive Haemophilus influenzae b (Hib) disease in Halton, and eight reported cases in all of Ontario. Hib is a bacterial infection, and most commonly manifests as meningitis (swelling of the fluid surrounding the spinal cord and brain). Symptoms often appear suddenly and include fever, vomiting, lethargy, and a stiff neck or back. Children receive vaccination against HiB at two, four, six, and 18 months. Children under the age of five are most likely to get Hib. Prior to the introduction of the Hib vaccine in 1998, Hib was the leading cause of bacterial meningitis in young children. Children attending licensed daycare centres are required to show proof of immunization unless exempt. Tetanus In 2015, there were no reported cases of tetanus in Halton and only one reported case in Ontario. Tetanus, also referred to as lockjaw, is characterized by painful muscle spasms, followed by stiff abdominal muscles. Death or serious complications can result with no treatment. Infection is introduced into the body through a break in the skin (puncture wound, bites, burns, etc.) by an object that has been contaminated with spores from the bacterium Clostridium tetani. Vaccination against tetanus is given to children at two, four, six, and 18 months, between four to six years, and again between 14 and 16 years. Adults should receive a booster dose every ten years. Rubella There have been no cases of rubella reported in Halton since 2005. The last reported case of rubella in Ontario was in 2014. Cases that occur in Canada are primarily in unimmunized groups, and Canada is close to reaching its goal of rubella elimination. Rubella is a viral disease that presents with a rash, fever, headache, malaise, runny nose, and red eyes. The rash begins on the face and usually spreads within 24 hours. Rubella infection in pregnant women can lead to serious complications including congenital rubella infection (see neonatal section), which can result in miscarriage, stillbirth, fetal malformations, and intellectual disabilities. As such, routine screening for rubella susceptibility is recommended among all women of childbearing age. 2015 Halton Region Infectious Disease Report 17 The measles, mumps and rubella (MMR) vaccine is given to children at 12 months, and again between the ages of four and six. Proof of vaccination is required for all children over the age of six to attend school in Ontario, unless exemption has been given. Diphtheria There have been no reported cases of diphtheria in Ontario since 1995. Cases still occur worldwide, mostly in developing nations. Diphtheria is an infection caused by the bacterium Corynebacterium diphtheriae. Diphtheria primarily affects the upper respiratory tract, and can also include fever, sore throat, difficulty swallowing, and malaise. Enlarged lymph nodes give the characteristic swollen neck. Diphtheria is spread from person to person through respiratory droplets from coughing or sneezing. Vaccines containing diphtheria are given to children at two, four, six, and 18 months, between four to six years, and again between 14 and 16 years. Adults should receive a booster dose every ten years. Polio Canada was certified as being polio-free since 1994, and the last case was detected in 1977. A single case of polio would be considered a public health emergency in Canada. Polio only remains endemic in three countries: Afghanistan, Nigeria and Pakistan. Polio (poliomyelitis) is caused by poliovirus. Over 90% of polio cases are asymptomatic. Fever, headache, malaise, nausea, and vomiting can often progress to severe muscle pain, stiffness of the back and neck, and acute flaccid paralysis which may be permanent. Paralysis of respiratory or swallowing muscles can cause death. Polio primarily affects children under the age of three. Polio vaccine is given to children at two, four, six, and 18 months, and between four to six years. Smallpox In 1979 the World Health Organization declared smallpox as eradicated worldwide. For this reason, if there were ever a single case of smallpox anywhere in the world it would be considered a global health emergency. Worries of using smallpox as a bioterrorism weapon exist. Smallpox is an acute disease caused by the variola virus. Smallpox results in a sudden onset of fever, malaise, headache, and severe backache. This is followed 2-4 days later by the characteristic skin eruptions which eventually scab and fall off 3-4 weeks later. Smallpox is not known to have any other reservoir than humans, and due to its eradication, immunization among the general public is not required. Individuals who have contact with the laboratory contained virus are vaccinated against smallpox. 2015 Halton Region Infectious Disease Report 18 Food- and water-borne diseases This section provides an overview on food-borne and water-borne diseases reported to the HRHD in 2015. Food-borne and water-borne diseases are caused by bacteria, parasites, and viruses that have found their way into food or water that is being consumed. Food can become contaminated by any number of sources, including infected humans or animals, as well as runoff from landfills, agricultural lands, or sewers. Because the route of exposure to food-borne and water-borne diseases is by ingestion, and because symptoms are usually related to the digestive tract, these diseases are also often referred to as enteric diseases – meaning that they are related to the intestine. Many of these diseases are sometimes also transmitted from person-to-person. These diseases may cause nausea, vomiting, abdominal pain, diarrhoea, bloody stools, fever, and severe systemic illness. Illnesses caused by toxins (e.g., from Staphylococcus aureus) or other toxic agents can also be spread by food and water. In 2015, there were 376 reported cases of food and water-borne diseases among Halton residents, accounting for 18% of the total cases of reportable infectious diseases that year. Figure 9 shows the number of cases of the most common food-borne and water-borne diseases in Halton residents in 2015 compared to the previous five-year averages. Food and water-borne diseases are the most common type of travel-related illness, typically acquired from improperly prepared foods or untreated water in countries that do not have food safety standards equivalent to Canada. In 2015, 41% of reported cases of food- and waterborne illness in Halton were associated with travel outside of Canada. Figure 9: Most frequently reported food- and water-borne diseases compared to previous five-year average, Halton residents, 2010-2015. Sources: Integrated Public Health Information System [2015], extracted April 20, 2016 In addition to the diseases highlighted in Figure 9, there were also a total of 29 cases of the following diseases, accounting for the remaining 8% of this disease category: Verotoxinproducing E. coli including haemolytic uraemic syndrome (HUS), cryptosporidiosis, legionellosis, shigellosis, listeriosis, typhoid fever and hepatitis A. There were no cases of paratyphoid fever, botulism, cholera, trichinosis, or paralytic shellfish poisoning reported in Halton in 2015. 2015 Halton Region Infectious Disease Report 19 Salmonellosis In 2015, there were 123 reported cases of salmonellosis in Halton, accounting for 33% of the reportable food- and water-borne diseases, and 6% of all reportable diseases. Salmonellosis is classified as a food-borne disease because contaminated food, mainly of animal origin, is the predominant mode of transmission. Symptoms of salmonellosis include abdominal pain, diarrhoea, vomiting, and fever. Symptoms generally present within 6-72 hours of ingesting contaminated food or water, and typically last four to seven days. As seen in Figure 10, the age-standardized incidence rate of salmonellosis reported in Halton has fluctuated over time, similar to Ontario. In 2015, there was no significant difference in the age-standardized incidence rate of salmonellosis between Halton and Ontario. The age-specific rate of salmonellosis was slightly higher in Halton among children aged 0-4 compared to other age groups. Figure 10: Salmonellosis crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015. Sources: Integrated Public Health Information System [2006-2015], extracted April 20, 2016; Population Estimates, IntelliHEALTH, Ontario Ministry of Health and Long-Term Care [2015], extracted March 21, 2015. Ontario data: Ontario Ministry of Health and Long-Term Care, Integrated Public Health System database, extracted by Public Health Ontario [January 22, 2016]. 2015 Halton Region Infectious Disease Report 20 Campylobacter enteritis In 2015, there were 123 reported cases of Campylobacter enteritis in Halton, accounting for 33% of the reportable food- and water-borne diseases, and 6% of all reportable diseases. Campylobacter enteritis is a bacterial disease most often caused by the bacterium Campylobacter jejuni, and less commonly Campylobacter coli. Animals – most frequently poultry and cattle – are the reservoirs of Campylobacter organisms. The most common mode of transmission of this disease is through ingestion of the organisms in undercooked meat, contaminated food or water, or unpasteurized milk. Person-to-person transmission is uncommon. Typical symptoms of Campylobacter enteritis can include diarrhoea (which may be bloody), abdominal pain, fever, nausea and vomiting, and malaise. Symptoms usually occur within 2-5 days of becoming infected with the bacteria, and may last for one or two weeks. Reported age-standardized incidence rates of Campylobacter enteritis in Halton and Ontario have fluctuated over the past 10 years, although there appears to be a general decline in the incidence rate in Halton (Figure 11). In 2015, there was no significant difference in the agestandardized incidence rate of Campylobacter enteritis between Halton and Ontario. Figure 11: Campylobacter enteritis crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015. Sources: Integrated Public Health Information System [2006-2015], extracted April 20, 2016; Population Estimates, IntelliHEALTH, Ontario Ministry of Health and Long-Term Care [2015], extracted March 21, 2015. Ontario data: Ontario Ministry of Health and Long-Term Care, Integrated Public Health System database, extracted by Public Health Ontario [January 22, 2016]. 2015 Halton Region Infectious Disease Report 21 Giardiasis In 2015, there were 46 reported cases of giardiasis in Halton, accounting for 12% of the reportable food- and water-borne diseases, and 2% of all reportable diseases. Reservoirs of giardiasis include humans, and possibly other wild and domestic animals such as the beaver. Giardiasis can be transmitted through food or water contaminated with the protozoan giardia parasite. Person-to-person transmission can occur by hand-to-mouth transfer of cysts from the faeces of an infected individual. This mode of transmission is especially common in institutions and day care centres. Giardiasis primarily affects the upper small intestine. Giardiasis can affect people in different ways, ranging from no symptoms, to acute, self-limited diarrhoea, or it may lead to intestinal symptoms such as chronic diarrhoea, abdominal cramps, bloating, fatigue, and weight loss. It can also negatively affect the body’s ability to absorb fats and fat-soluble vitamins. Symptoms typically present within one to three weeks of exposure to the giardia parasite. Similar to other food- and water-borne diseases, age-standardized rates of reported giardiasis in Halton have varied over the past 10 years, although in general there appears to be a slight decrease in the incidence of giardiasis in both Halton and Ontario (Figure 12). In 2015, there was no statistically significant difference in the age-standardized rate of giardiasis in Halton and Ontario. Figure 12: Giardiasis crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015. Sources: Integrated Public Health Information System [2006-2015], extracted April 20, 2016; Population Estimates, IntelliHEALTH, Ontario Ministry of Health and Long-Term Care [2015], extracted March 21, 2015. Ontario data: Ontario Ministry of Health and Long-Term Care, Integrated Public Health System database, extracted by Public Health Ontario [January 22, 2016]. 2015 Halton Region Infectious Disease Report 22 Amebiasis In 2015, there were 25 reported cases of amebiasis in Halton, accounting for 7% of the reportable food- and water-borne diseases, and 1% of all reportable diseases. Amebiasis is an infection of the intestines caused by the parasite Entamoeba histolytica. The infection is spread through food or water that has been contaminated by infected faeces. It can also be spread from person-to-person. Many people with amebiasis do not have any symptoms. If symptoms do occur, they typically appear between one week and one month of being exposed to the parasite, and may include abdominal cramps, diarrhoea, and fatigue. In severe cases, fever, vomiting and bloody stools may also occur. The period between exposure to the parasite and the onset of symptoms is variable and can range anywhere from a few days to years, however it most commonly occurs over 2 to 4 weeks. Age-standardized rates of amebiasis have remained fairly constant in Ontario over the past 10 years, but have varied from year to year in Halton (Figure 12). Over the past 10 years, the agestandardized rate of giardiasis has been lower in Halton than Ontario, however in 2015 this difference was not statistically significant. Figure 13: Amebiasis crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015. Sources: Integrated Public Health Information System [2006-2015], extracted April 20, 2016; Population Estimates, IntelliHEALTH, Ontario Ministry of Health and Long-Term Care [2015], extracted March 21, 2015. Ontario data: Ontario Ministry of Health and Long-Term Care, Integrated Public Health System database, extracted by Public Health Ontario [January 22, 2016]. 2015 Halton Region Infectious Disease Report 23 Cyclosporiasis In 2015, there were 17 reported cases of cyclosporiasis in Halton, accounting for 5% of the reportable food- and water-borne diseases, and about 1% of all reportable diseases. Cyclosporiasis is an intestinal infection caused by the parasite Cyclospora cayetanensis. The infection is spread through food or water that has been contaminated by faeces infected with the parasite. Diarrhoea is a typical symptom of cyclosporiasis, and other common symptoms include loss of appetite, stomach pain, nausea, and fatigue. Vomiting, fever and flu-like symptoms may also be present. Symptoms typically begin within about one week of becoming infected with the parasite, however not all people experience symptoms. In 2015, there was an increase in the age-standardized incidence rate of cyclosporiasis in Halton and throughout Ontario. This increase was likely due to a national outbreak of non-travel related cyclosporiasis over the summer (May 3-Aug 8 2015). The source of this outbreak remains unidentified.7 In 2015, Halton had a higher age-standardized rate of cyclosporiasis compared to Ontario, however this difference was not statistically significant (Figure 14). Figure 14: Cyclosporiasis crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015. Sources: Integrated Public Health Information System [2006-2015], extracted April 20, 2016; Population Estimates, IntelliHEALTH, Ontario Ministry of Health and Long-Term Care [2015], extracted March 21, 2015. Ontario data: Ontario Ministry of Health and Long-Term Care, Integrated Public Health System database, extracted by Public Health Ontario [January 22, 2016]. 2015 Halton Region Infectious Disease Report 24 Yersiniosis In 2015, there were 13 reported cases of yersiniosis in Halton, accounting for approximately 3% of the reportable food- and water-borne diseases, and less than 1% of all reportable diseases. Yersiniosis is caused by consumption of food or water contaminated with the bacteria Yersinia, or through person-to-person contact with an infected individual. One of the most common sources of the bacteria is raw or undercooked pork, as well as other meats, fish and milk. Symptoms of yersiniosis differ depending on age. Children often experience fever, abdominal pain and diarrhea, and older children and adults typically experience fever and abdominal pain on their right side. Symptoms of yersiniosis usually appear within three to seven days of becoming infected, and can last for two to three weeks. In Ontario, age-standardized incidence rates of yersiniosis have decreased slightly over the last 10 years, while rates in Halton have been variable, which is expected due to the small number of cases (Figure 15). In 2015, the age-standardized rate of yersiniosis in Halton was not significantly different from Ontario. Figure 15: Yersiniosis crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015. Sources: Integrated Public Health Information System [2006-2015], extracted April 20, 2016; Population Estimates, IntelliHEALTH, Ontario Ministry of Health and Long-Term Care [2015], extracted March 21, 2015. Ontario data: Ontario Ministry of Health and Long-Term Care, Integrated Public Health System database, extracted by Public Health Ontario [January 22, 2016]. Verotoxin-producing E. coli with haemolytic uraemic syndrome In 2015, there were eight reported cases of verotoxin-producing E. coli with haemolytic uraemic syndrome, accounting for about 2% of food- and water-borne illnesses reported in Halton. In 2015, the age-standardized rate of reported cases of verotoxin-producing E. coli with HUS was similar in Halton and Ontario. Verotoxin-producing E. coli is a group of bacteria, which is often found in animals such as cattle, sheep, pigs, and goats, and can cause illness in humans. It is spread by ingesting contaminated 2015 Halton Region Infectious Disease Report 25 food or water, as well as person-to-person via the fecal-oral route (transmission of the pathogen from faeces to the mouth). Some sources of exposure to verotoxin-producing E. coli include raw or undercooked ground beef, raw fruits and vegetables, and unpasteurized milk and juice. Symptoms of Verotoxin-producing E. coli typically appear 3 to 4 days after exposure to the pathogen, and may include stomach cramps, malaise, vomiting, and diarrhoea (which can be bloody). In some cases, a serious complication involving the kidneys can occur, called haemolytic uraemic syndrome (HUS), which may lead to life-threatening kidney failure. Young children are particularly at risk of developing HUS, as well as older adults. Cryptosporidiosis In 2015, there were six reported cases of cryptosporidiosis in Halton. In 2015, the agestandardized rate of reported cases of cryptosporidiosis was lower in Halton compared to Ontario. Cryptosporidiosis (often referred to as “crypto”) is a disease caused by the parasite Cryptosporidium. Cryptosporidium is transmitted through the faecal-oral route, often via contaminated water. The most common symptoms of cryptosporidiosis include watery diarrhoea, abdominal pain, and cramping, although not all people infected with the parasite experience any signs or symptoms. For people with weakened immune systems, such as individuals with HIV/AIDS, cryptosporidiosis can be life threatening. Symptoms of cryptosporidiosis begin on average one week from infection with the parasite, and can last for a month or less in healthy individuals, or longer for those who are immunocompromised. Legionellosis In 2015, there were five reported cases of legionellosis in Halton. In 2015, there was no significant difference between Halton and Ontario in the age-standardized rate of reported cases of legionellosis. Legionellosis consists of two respiratory illnesses caused by the Legionella bacteria. The bacteria are found in warm water, such as water from hot tubs, hot water tanks and plumbing systems. People can become exposed to the Legionella bacteria if they breathe in mist or vapor contaminated with the bacteria. If the respiratory infection caused by the Legionella bacteria is severe and causes pneumonia, it is referred to as Legionnaires’ disease. Other symptoms include cough, headache, malaise, loss of appetite and fever. Symptoms typically begin within two weeks of being exposed to the bacteria, and can last several months. Legionnaires’ disease is a relatively uncommon disease, as fewer than 5% of people who are exposed to the bacteria actually develop the disease. Pontiac fever is a milder illness caused by Legionella, which has flu-like symptoms without pneumonia. Symptoms of Pontiac fever typically begin within 24-48 hours, and usually resolve within a few days without treatment. 2015 Halton Region Infectious Disease Report 26 Shigellosis In 2015, there were five reported cases of shigellosis in Halton. There was no statistically significant difference in the age-standardized rate of shigellosis reported in Halton compared to Ontario in 2015. Shigellosis is an infectious disease of the intestines caused by the Shigella bacteria. Shigellosis is spread through direct or indirect fecal-oral contact, including eating food or water contaminated with Shigella bacteria. Symptoms of shigellosis include fever, diarrhoea (which may be bloody), nausea, vomiting and fever. Symptoms typically begin within one to three days after exposure to the bacteria, and illness typically can last for four to seven days. People who are infected with the Shigella bacteria can continue to be infectious for four weeks after the illness. Some people can be infected with the bacteria and not show any symptoms, but still spread the infection on to others. Similar to other food and waterborne illnesses, shigellosis cases in Halton are often travelrelated. Listeriosis In 2015, there were two reported cases of listeriosis in Halton, and 65 cases in all of Ontario. Listeriosis is a disease that occurs when people eat or drink food or beverages contaminated with the bacteria Listeria monocytogenes. Common sources of Listeria include ready-to-eat meats, unpasteurized milk and cheeses, as well as raw vegetables. Symptoms of listeriosis include nausea, vomiting, muscle aches and cramps, diarrhea, and fever. In serious cases, the infection can spread to the nervous system and cause meningoencephalitis (brain infection), septicemia (blood poisoning), endocarditis (infection of the lining of the heart), and death. The length of time between infection and onset of symptoms, as well as the length of the illness is variable. Typhoid fever In 2015, there were two reported cases of typhoid fever in Halton, and 63 cases in all of Ontario. Typhoid fever is an infection caused by the bacteria Salmonella typhi. Typhoid fever is transmitted via the faecal-oral route, most often through eating food or water contaminated by infected human faeces. Cases of typhoid fever in Canada are typically acquired abroad, with the highest risk being among travellers to South Asia. Symptoms of typhoid fever are variable and may include fever, headache, malaise, cough, nausea, abdominal pain, and loss of appetite, and typically occur within one to two weeks of becoming infected. In severe cases, typhoid fever can cause delirium and confusion. Some people with fair skin also develop rose colored spots on their torso. In Canada, typhoid immunization is available and recommended for most people travelling to South Asia. 2015 Halton Region Infectious Disease Report 27 Hepatitis A In 2015, there was one reported case of Hepatitis A in Halton, and 70 cases in all of Ontario. Hepatitis A is a viral infection of the liver that is spread through food or water contaminated with the faeces of an infected person, or through close contact with an infected person. Common sources include uncooked food such as shellfish and produce. Symptoms of Hepatitis A can include fever, loss of appetite, abdominal discomfort, jaundice, dark colored urine, and light coloured stools. The time between exposure to the virus and onset of symptoms is variable, but on average takes about one month. Hepatitis A is one of the most common vaccine-preventable diseases among travellers. Hepatitis A is common in areas with poor sanitation, with a higher risk among travellers to Africa, Asia, and Central and South America. The Hepatitis A vaccine is recommended for travelers to high risk areas, as well as various other high risk groups. To achieve immunization, a first dose of the vaccine is given, followed by a booster dose six months to three years later, depending on the type of vaccine. Paratyphoid fever In 2015, there were no reported cases of paratyphoid fever in Halton, and 46 cases in all of Ontario. The last reported case in Halton was in 2014. Paratyphoid fever is a disease caused by several strains of the bacteria Salmonella enterica. Paratyphoid fever is not known to be endemic in Ontario, and cases are almost always travelacquired from other areas of the world such as South and South-East Asia. Paratyphoid fever is transmitted via the faecal-oral route, including ingestion of food and water contaminated by the faeces of infected individuals. Common sources include contaminated milk, raw fruit and vegetables, and shellfish. Symptoms of paratyphoid fever take one to 10 days to appear after exposure to the bacteria, and include fever, headache, malaise, loss of appetite, and a decrease in bowel movements. Symptoms can also include decreased heart rate, enlargement of the spleen, and rose coloured spots on the chest. Botulism In 2015, there were no reported cases of botulism in Halton, and five cases in all of Ontario. The last reported case of botulism in Halton was in 2012. Foodborne botulism is caused by ingesting toxins produced by the bacteria Clostridium botulinum in contaminated food. Common sources of botulism include canned foods, home preserved foods, and smoked or salted fish. Other types of botulism include wound botulism, which occurs when a wound is contaminated by C. botulinum (most often among injection drug users), and infant botulism, which is caused by ingesting spores of the botulinum bacteria, which grows and releases toxins in the intestines. Symptoms of botulism include fatigue, weakness, vertigo, blurred vision, difficulty speaking and dry mouth. Symptoms may progress to paralysis and in rare cases, death. In foodborne 2015 Halton Region Infectious Disease Report 28 botulism symptoms typically begin within 12 to 36 hours of consuming the toxin, and with wound botulism it may take up to two weeks for symptoms to occur. In Ontario, a single case of foodborne botulism or wound botulism should be treated as an outbreak, whereas two cases of infant botulism should be investigated as an outbreak. Cholera In 2015, there were no cases of cholera reported in Halton, and one case in all of Ontario. The last reported case of cholera in Halton was in 2008. Cholera is caused by toxin-producing strains of the bacteria Vibrio cholerae. Cholera is transmitted by consuming food or water contaminated by vomit or faeces infected with V. cholera. Cholera is not endemic to Canada, and cases are associated with travel to areas of the world where it is endemic. Symptoms of cholera typically include diarrhoea and vomiting, however most people infected with V. cholerae do not experience any symptoms. Severe cases can result in dehydration and death. Symptoms typically begin within a few hours to 5 days of becoming infected with V. cholerae. Trichinosis In 2015 there were no reported cases of trichinosis in Halton, and one case in all of Ontario. Trichinosis is a foodborne illness found worldwide. It is caused by the intestinal roundworm Trichinella, and is typically acquired from eating infected pork or meat from wild animals. After humans eat meat infected with Trichinella larvae, the larvae grow into adult worms and reproduce. Initial symptoms may include abdominal pain, nausea, vomiting or diarrhea. Within a few weeks of consuming the infected meat, the larvae then travel through tissues in the body including muscle, and symptoms may include muscle pain, fever, weakness, headache, conjunctivitis, and bleeding under the nails. Risk of trichinosis can be reduced by implementing food safety procedures such as cooking meat to a sufficient internal temperature. Paralytic shellfish poisoning In 2015, there were no cases of paralytic shellfish poisoning in Halton or Ontario. There has only been one reported case of paralytic shellfish poisoning in Ontario since it became a reportable disease in September 2013. Paralytic shellfish poisoning is caused by neurotoxins present in shellfish that are produced by phytoplankton or dinoflagellates in the ocean. Symptoms of paralytic shellfish poisoning typically begin within 30 minutes to three hours of ingesting the toxin, and include tingling or numbness, dizziness, vomiting, headache, paralysis of the arms and legs, lack of balance and coordination, as well as incoherent speech. In severe cases it can lead to respiratory failure and death. The Canadian Food Inspection Agency is responsible for monitoring for water quality in areas where shellfish are harvested, as well as testing for paralytic shellfish poisoning. 2015 Halton Region Infectious Disease Report 29 Sexually-transmitted and blood-borne infections This section provides an overview of the sexually-transmitted infections (STIs) and blood-borne infections reported to the HRHD in 2015. Reportable STIs include a number of viral and bacterial infections that are primarily transmitted by oral, vaginal, and/or anal intercourse. Other terms for STIs include sexually-transmitted diseases (STDs), and venereal diseases. Bloodborne infectious diseases are spread primarily through “blood-to-blood contact”. People who are at a higher risk for blood-borne infectious diseases include injection drug users, and healthcare workers and workers in other occupations who may be exposed to needle stick or other sharps injuries. While blood transfusions could also be a source of blood-borne infectious disease, the risk of transmission of infectious diseases through blood in Canada is low due to effective donor screening and laboratory tests. In 2015, there were 1171 reported sexually-transmitted and blood-borne infections in Halton, accounting for over half of all reportable diseases in Halton. Figure 16 shows the reported number of cases of sexually-transmitted and blood-borne infections among Halton residents in 2015 compared to the previous five-year averages. There were no cases of chancroid reported in Halton in 2015. Figure 16: Most frequently reported sexually-transmitted and blood-borne infections in Halton compared to previous five-year average, Halton residents, 2010-2015. Sources: Integrated Public Health Information System [2015], extracted April 20, 2016 *Excludes early congenital syphilis 2015 Halton Region Infectious Disease Report 30 Chlamydial infections In 2015, there were 916 reported cases of chlamydia in Halton, accounting for 78% of all reportable sexually-transmitted and blood-borne infections and 44% of all reportable diseases. Chlamydia is an STI caused by the bacteria Chlamydia trachomatis, and the most common sexually-transmitted infection reported in Halton and Ontario. In men, symptoms of chlamydia include discharge from the penis, pain or discomfort when urinating, and redness, itching, and swelling of the urethra. In females, chlamydia may present as a cervical infection with pain or bleeding during sexual intercourse, bleeding between periods, and discomfort when urinating. The majority of females with chlamydial infections, however, do not experience any symptoms. This infection is therefore likely to be underreported. In 2015, the age-standardized incidence rate of chlamydia in Halton was significantly lower than Ontario (Figure 17). The age-standardized incidence rate of chlamydia in Halton increased by 38% between 2006 and 2015, from 125 per 100,000 to 203 per 100,000 (Figure 17). This is consistent with the general rise in chlamydia rates seen in Ontario over the past ten years. Some of the increase in chlamydia rates throughout the province can be attributed to improved quality and acceptability of screening and testing methods. However, chlamydia continues to be considered a “hidden epidemic” due to lack of awareness about the problem, and because the majority of cases do not have any symptoms but are still infectious. Awareness-raising initiatives around the importance of safer sex practice (particularly condom use) and STI testing continue to be important components of health promotion campaigns concerning chlamydia and other STIs. Figure 17: Chlamydia crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015. Sources: Integrated Public Health Information System [2006-2015], extracted April 20, 2016; Population Estimates, IntelliHEALTH, Ontario Ministry of Health and Long-Term Care [2015], extracted March 21, 2015. Ontario data: Ontario Ministry of Health and Long-Term Care, Integrated Public Health System database, extracted by Public Health Ontario [January 22, 2016]. 2015 Halton Region Infectious Disease Report 31 Similar to Ontario, the majority of chlamydia cases in Halton in 2015 were youth and young adults. Halton females aged 15-24 were significantly more likely than males to have reported cases of chlamydia (Figure 18: Chlamydia age-specific incidence rates (per 100,000), by sex, Halton residents, 2015.). The higher rate of chlamydia among females may be related to a larger number of women screened for this infection compared to men. Figure 18: Chlamydia age-specific incidence rates (per 100,000), by sex, Halton residents, 2015. Sources: Integrated Public Health Information System [2006-2015], extracted April 20, 2016; Population Estimates, IntelliHEALTH, Ontario Ministry of Health and Long-Term Care [2015], extracted March 21, 2015. 2015 Halton Region Infectious Disease Report 32 Gonorrhoea In 2015, there were 117 reported cases of gonorrhoea infection in Halton, accounting for 10% of all reportable sexually-transmitted and blood-borne infections and 6% of all reportable infectious diseases in Halton. Gonorrhoea is a sexually-transmitted bacterial infection, which differs in males and females in course, severity, and ease of recognition. Worldwide, this infection affects both men and women, especially sexually active adolescents and younger adults. Untreated individuals may be infectious for months. The age-standardized incidence rate of gonorrhoea had been relatively stable between 2006 and 2013, however, both Halton and Ontario have seen an increase in rates over the past three years (Figure 19). The age-standardized incidence rate of gonorrhoea in Halton continues to be significantly lower than in Ontario. Public Health Ontario has been monitoring this increase provincially and has reported that “it is not fully understood and likely multifactorial” (PHO Monthly Infectious Disease Report, February 2015).8 In particular they are examining antibiotic sensitivity, adherence to treatment and testing guidelines, and have undertaken an evaluation of Ontario’s provincial treatment guidelines.9 Figure 19: Gonorrhoea crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015. Sources: Integrated Public Health Information System [2006-2015], extracted April 20, 2016; Population Estimates, IntelliHEALTH, Ontario Ministry of Health and Long-Term Care [2015], extracted March 21, 2015. Ontario data: Ontario Ministry of Health and Long-Term Care, Integrated Public Health System database, extracted by Public Health Ontario [January 22, 2016]. 2015 Halton Region Infectious Disease Report 33 Similar to Ontario, the majority of gonorrhoea cases in Halton were in youth and young adults. Males in Halton had higher rates of reported gonorrhoea compared to females, particularly among males aged 20-39 (Figure 20). This higher rate of gonorrhoea in males compared to females is likely due to more males seeking treatment for gonorrhoea symptoms, as most women with gonorrhoea do not experience any symptoms or they may only experience mild symptoms. Figure 20: Gonorrhoea age-specific incidence rates (per 100,000), by sex, Halton residents, 2015. Sources: Integrated Public Health Information System [2006-2015], extracted April 20, 2016; Population Estimates, IntelliHEALTH, Ontario Ministry of Health and Long-Term Care [2015], extracted March 21, 2015. 2015 Halton Region Infectious Disease Report 34 Hepatitis C In 2015, there were 99 reported cases of hepatitis C virus infection among Halton residents, accounting for 8% of reportable sexually-transmitted and blood-borne infections, and about 5% of all reportable diseases in Halton. Symptoms of hepatitis C infection are typically mild, and may include loss of appetite, abdominal discomfort, fatigue, nausea and vomiting. Many people do not experience any symptoms. Between 50-80% of those infected with the hepatitis C virus will develop chronic infection, which may lead to liver damage (cirrhosis), liver cancer, or liver failure. Hepatitis C is primarily spread by blood-to-blood contact, with sharing needles being one of the highest risk factors for infection. While the risk is low, it is also possible to acquire the infection from unprotected sex with an infected individual if there is blood-to-blood contact. Mother-tochild transmission has also been documented, but it is rare. Important interventions to reduce the risk of hepatitis C include harm reduction strategies such as needle exchange programs, as well as infection control procedures in healthcare settings to reduce the risk of exposure for healthcare workers. The age-standardized rate of hepatitis C in Halton has declined in recent years, from 29 per 100,000 in 2007 to 19 per 100,000 in 2015 (Figure 21). The age-standardized rate of hepatitis C in Ontario also declined slightly during the same time period. In 2015, the age-standardized rate of hepatitis C was significantly lower in Halton compared to Ontario. It is important to consider, however, when interpreting reported hepatitis C rates over time that most cases are reported months or years following infection. Figure 21: Hepatitis C crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015. Sources: Integrated Public Health Information System [2006-2015], extracted April 20, 2016; Population Estimates, IntelliHEALTH, Ontario Ministry of Health and Long-Term Care [2015], extracted March 21, 2015. Ontario data: Ontario Ministry of Health and Long-Term Care, Integrated Public Health System database, extracted by Public Health Ontario [January 22, 2016]. 2015 Halton Region Infectious Disease Report 35 Syphilis In 2015, there were 27 reported cases of syphilis: 6 infectious and 21 other (non-infectious or unspecified) cases in Halton, accounting for 2% of reportable sexually-transmitted and bloodborne infections. Syphilis is a complex sexually-transmitted bacterial infection with four stages. Primary syphilis is characterized clinically by a primary lesion called a chancre (painless ulcer). Secondary syphilis is characterized by a rash that typically appears on the palms of hands and soles of feet and/or mucous membrane lesions in the mouth, vagina or anus. At this stage, fever and malaise may also be present. The latent stage of syphilis begins when the symptoms of the previous stages disappear. Untreated latent syphilis can progress to tertiary syphilis, which can involve cardiovascular and neurological complications and may lead to death. Primary, secondary and early latent syphilis are considered infectious, while late latent and tertiary syphilis are considered non-infectious. Syphilis can also be passed from an infected mother to an unborn infant through the placenta, or at the time of birth (see Early congenital syphilis). The age-standardized rate of syphilis has decreased slightly in Ontario, and fluctuated in Halton over the past 10 years (Figure 9). In 2015, the age-standardized rate of syphilis in Halton was significantly lower than Ontario. Newly diagnosed non-infectious syphilis cases are found primarily through screening and the higher rates of non-infectious disease may reflect increased screening. While cases of noninfectious syphilis may have actually been acquired years before they are diagnosed and reported, they are still counted as incident cases in the year of diagnosis. Figure 22: Syphilis crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015. Sources: Integrated Public Health Information System [2006-2015], extracted April 20, 2016; Population Estimates, IntelliHEALTH, Ontario Ministry of Health and Long-Term Care [2015], extracted March 21, 2015. Ontario data: Ontario Ministry of Health and Long-Term Care, Integrated Public Health System database, extracted by Public Health Ontario [January 22, 2016]. 2015 Halton Region Infectious Disease Report 36 HIV and AIDS In 2015, there were 11 reported cases of HIV and one reported case of AIDS in Halton. Human Immunodeficiency Virus (HIV) is a virus that targets the body’s immune system. Symptoms of HIV infection are variable and may include mild flu-like symptoms such as fever, sore throat, headaches and swollen lymph nodes. Left untreated, the infection progressively interferes with the body’s immune system. HIV infection becomes AIDS when the immune system is severely weakened (measured by CD4 cell count) or a person develops one or more opportunistic infections. Most people with AIDS die from an infection, cancer, or other disease that they were more susceptible to because of their weakened immune systems. The prognosis for people with HIV has improved immensely in recent decades. With treatment, HIV is a manageable disease and many people with the infection can live long lives. HIV is transmitted from person to person through unprotected sexual intercourse, blood, breast milk, and contact with sexual bodily fluids. It can also be transmitted from mother to child. The period in which a person with HIV can spread the infection on to others is not precisely known, however people are most infectious during the first months of infection, when they have other STIs present, and when they have a high viral load. Certain population groups that tend to have a higher risk of acquiring HIV include men who have sex with men and injection drug users. There has been a general decrease in the age-standardized rate of HIV in Ontario, while rates in Halton have fluctuated (which is to be expected due to the small number of cases each year) (Figure 23). In 2015, the age-standardized rate of HIV in Halton was significantly lower than Ontario. Figure 23: HIV crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015. Sources: Integrated Public Health Information System [2006-2015], extracted April 20, 2016; Population Estimates, IntelliHEALTH, Ontario Ministry of Health and Long-Term Care [2015], extracted March 21, 2015. Ontario data: Ontario Ministry of Health and Long-Term Care, Integrated Public Health System database, extracted by Public Health Ontario [January 22, 2016]. 2015 Halton Region Infectious Disease Report 37 Chancroid Chancroid is very rare in North America, and there have been no reported cases of chancroid in Ontario since 1997. Chancroid is most common in tropical and subtropical regions of the world. Chancroid is a bacterial infection caused by Haemophilus ducreyi. Chancroid is characterized by a single, or multiple open, painful sores on the genitals. It is transmitted by direct sexual contact with the open sores. People with chancroid can spread the infection to others until the sores are healed, which can take anywhere from weeks to months without treatment, or one to two weeks with antibiotic treatment. 2015 Halton Region Infectious Disease Report 38 Neonatal infectious diseases In 2015, there were three cases of reportable neonatal diseases: two cases of neonatal group B streptococcal disease, and one case of early congenital syphilis. Reportable neonatal diseases are those that are transferred from mother to infant either through the placenta, or through the birth canal at the time of birth. Neonatal group B streptococcal disease In 2015 there were two reported cases of neonatal group B streptococcal disease in Halton, and 43 cases in all of Ontario. Approximately 10-30% of pregnant women have the group B streptococci bacteria in their genital tract. The bacteria can be passed from the mother to her infant in utero or through the birth canal in early onset transmission, or through person-to-person contact with late onset transmission. Infection with the bacteria can be life-threatening in infants, and cause septicemia (blood infection), pneumonia, or meningitis. The risk of neonatal group B streptococcal disease is greatly reduced through prenatal screening for group B streptococci. Antibiotic treatment can prevent the spread of the bacteria from mother-to-child. Proper hand-washing procedures can also help reduce the spread of the bacteria once the infant is born. Early congenital syphilis There was one reported case of early congenital syphilis in Halton in 2015, and three cases in all of Ontario. Congenital syphilis is a life-threatening infection in infants, contracted from an infected mother through the placenta or at the time of birth. Congenital syphilis can result in stillbirth, pre-term birth or other serious complications. Screening for syphilis is recommended as a routine prenatal test. Treatment of infected mothers for syphilis lowers the risk to the infant. Congenital rubella syndrome In 2015 there were no reported cases of congenital rubella syndrome in Halton or Ontario. The last reported case of congenital rubella syndrome in Ontario was in 2009. Congenital rubella syndrome occurs when a pregnant mother infected with rubella virus passes the virus onto their infant. Risk of fetal infection is particularly high during the first trimester of pregnancy. Congenital rubella syndrome can result in miscarriage, stillbirth, and numerous other complications such as deafness, intellectual disabilities and congenital heart disease. Some infants with congenital rubella syndrome may appear healthy at birth, but may later develop eye, ear or brain damage. As the rubella virus is not endemic in Canada, a single case of congenital rubella syndrome would be considered an outbreak. Vaccination against rubella (MMR vaccine) prior to pregnancy is important to prevent pregnant mothers from becoming infected with rubella and passing it onto their unborn infants. 2015 Halton Region Infectious Disease Report 39 Opthalmia neonatorum There were no cases of opthalmia neonatorum in Halton in 2015, and three cases in all of Ontario. There have been no reported cases in Halton over the last 10 years. Opthalmia neonatorum is a serious eye infection that can occur when either Neisseria gonorrhoeae (the bacterium that causes gonorrhoea) or Chlamydia trachomatis (the bacterium that causes chlamydia) is passed from an infected mother to her infant during birth. Symptoms of opthalmia neonatorum include swollen red eyelids and discharge from the eyes, and typically occur within 3 weeks of birth. Under the Health Protection and Promotion Act, it is required that new-born babies are treated with an eye drop solution that destroys any infectious bacteria that might cause opthalmia neonatorum. 2015 Halton Region Infectious Disease Report 40 Zoonotic, vector-borne and exotic diseases This section provides an overview of zoonotic, vector-borne and exotic infectious diseases. Zoonotic diseases are diseases that can be passed between humans and animals. Vectorborne diseases are spread to people by small organisms like mosquitos and ticks. Exotic diseases refer to other diseases that are not normally found in Ontario and Halton. In 2015, there were 16 diseases (all vector-borne) reported in Halton, accounting for less than 1% of all reportable diseases. Figure 24 shows the reported number of cases of these vectorborne infections among Halton residents in 2015 compared to the previous five-year averages. There were no cases of any of the other 12 reportable zoonotic, exotic, or vector-borne infectious diseases in Halton in 2015. Figure 24: Most frequently reported zoonotic and exotic infections in Halton compared to previous five-year average, Halton residents, 2010-2015. Sources: Integrated Public Health Information System [2015], extracted April 20, 2016 2015 Halton Region Infectious Disease Report 41 Lyme disease In 2015 there were 10 reported cases of Lyme disease in Halton. Of these ten cases, five were associated with travel to risk areas within Ontario, three were associated with travel to another country where Lyme disease is endemic, one was associated with travel to Eastern Canada, and one case may have been exposed within Halton Region. Lyme disease is a zoonotic disease caused by the bacterium Borrelia burdorgeri. The bacteria are spread by the bite of a black-legged tick. Lyme disease occurrence varies with the season, and is more common in the summer due to increased activity outdoors and the higher presence of infectious ticks in the environment. There are three stages of Lyme disease. In the early localized stage, infected individuals may experience the characteristic “bulls eye” rash at the site of the tick bite, as well as fever, stiff neck, headache, and muscle and joint pain. In the early disseminated stage, neurological problems may begin, such as twitching of the facial muscles or facial paralysis, meningitis, fatigue, and muscle and joint pain. Late stages of the disease may involve further problems with the heart, nervous system and joints including arthritis, meningitis, and behaviour changes. Most cases of Lyme disease can be treated with antibiotics. Taking steps to avoid tick bites, such as wearing insect repellent and clothes that cover the body, can help reduce the risk of Lyme disease. Halton residents who find a tick on themselves or family members can submit ticks to the Halton Region Health Department for testing. The age-standardized rate of Lyme disease in Halton was lower than Ontario in 2015, however this difference was not statistically significant. In Ontario, the age-standardized rate of Lyme disease is on the rise. In 2015 there were 419 reported cases of Lyme disease in Ontario, which was the highest number of cases of Lyme disease ever reported. For more information on Lyme disease in Ontario in 2015, see the PHO Monthly Infectious Diseases Surveillance Report, December 2015. Figure 25: Lyme disease crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015. Sources: Integrated Public Health Information System [2006-2015], extracted April 20, 2016; Population Estimates, IntelliHEALTH, Ontario Ministry of Health and Long-Term Care [2015], extracted March 21, 2015. Ontario data: Ontario Ministry of Health and Long-Term Care, Integrated Public Health System database, extracted by Public Health Ontario [January 22, 2016]. 2015 Halton Region Infectious Disease Report 42 Malaria In 2015 there were five reported cases of malaria in Halton Region. The age-standardized rate of malaria in Halton was not statistically significantly different from Ontario in 2015. Malaria is a disease caused by parasites from the Plasmodium genus, and is transmitted through the bite of a female Anopheles mosquito. Malaria is a major cause of illness in tropical areas throughout Africa, Asia, Central and South America. Malaria is not endemic to Ontario, and therefore reported cases in Halton are due to travel-acquired infections or acquired prior to immigrating to Canada from a country where malaria is endemic. Common symptoms of malaria include fever, chills, sweats and headache. Complications of malaria can include coma, as well as liver, kidney and other organ failure and can result in death. With certain types of malaria infection, relapses of the disease may occur. The incubation period for malaria is variable depending on the Plasmodium species they are infected with, and can range from weeks to months. Personal protection against insect bites and vector control are important preventative measures for malaria. West Nile virus illness In 2015, there was one reported case of West Nile virus in Halton, and 34 cases in total throughout all of Ontario. This was significantly lower than the previous five year average of 9 cases of West Nile virus per year in Halton. West Nile virus is a Flavivirus that is most commonly transmitted to humans via mosquitos in the genus Culex. Birds are the primary reservoir for West Nile virus (site where the virus normally lives and replicates). West Nile virus was first reported in Uganda in the 1930s, and first appeared in Ontario in 2002. The majority of West Nile virus infections occur in Ontario during the summer months, and incidence rates fluctuate due to differences in weather and the size of the mosquito population from year to year. Most people who are infected with West Nile virus do not have any symptoms. For those that do experience symptoms, symptoms typically appear within 2-15 days of becoming infected with the virus. Mild cases of West Nile virus may experience a flu-like illness, including fever, headache, body ache and skin rash. In serious cases, neurological complications may occur, including encephalitis and meningitis. Q fever In 2015, there were no reported cases of Q fever in Halton, and 15 reported cases in all of Ontario. The last reported case of Q fever in Halton was in 2013. Q fever is caused by the bacterium Coxiella burnetii. Reservoirs of the bacteria include cattle, goats, sheep, dogs and cats, as well as several wild animals. Coxiella burnetii is shed by infected animals in their urine, feces, milk, and in the amniotic fluids and placenta during birth. Humans can become infected by inhaling dust particles that are contaminated by the infected animals. People who spend time with animals, such as farmers and veterinarians, are at highest risk for the disease. There is also concern that this Coxiella burnetii could be used for bioterrorism, as it is resistant to many disinfectants, and can become airborne and cause disease in humans when inhaled. 2015 Halton Region Infectious Disease Report 43 Over half of those infected with Coxiella burnetii do not have any symptoms. Acute symptoms of Q fever are variable, and may include high fever, headache, fatigue, cough, diarrhoea, nausea and sensitivity to light. In less than 5% of cases, chronic Q fever may develop, which often presents as endocarditis (inflammation of the lining of the heart valves). Brucellosis There were no reported cases of brucellosis in Halton in 2015, and five cases in all of Ontario. The last reported case of brucellosis in Halton was in 2009. Brucellosis is a disease caused by the Brucella bacteria. Reservoirs of brucellosis include several domestic animals such as cattle, sheep and pigs, as well as wild animals like deer and bison. Humans can become infected with brucellosis through eating or drinking raw dairy products from an infected animal, from breathing in the bacteria, and when the bacteria from the animals enters the body through wounds in the skin or through mucous membranes. People who work with livestock, including farmers and veterinarians, are most at risk for brucellosis. Cattle in Ontario have been declared brucellosis free. Symptoms of brucellosis most commonly occur within 1-2 months of exposure to the pathogen, and include fever that comes and goes, headache, weakness, chills, aches and pains, and weight loss. In serious cases, meningitis, endocarditis and osteomyelitis (bone infection) may occur. Leprosy In 2015, there were no reported cases of leprosy in Halton, and three cases in all of Ontario. The last reported case of leprosy in Halton was in 2011. Leprosy is a disease that primarily involves the skin and is caused by the bacterium Mycobacterium leprae. It is likely that the bacterium is transmitted from person-to-person through infected respiratory droplets and nasal secretions. Main symptoms of leprosy include skin lesions and skin growths. The disease can also damage the nervous system and lead to muscle weakness and numbness in the arms, hands, legs and feet. Symptoms can take many years to appear after becoming infected with the bacteria. Leprosy is not endemic to Canada, and cases reported in Canada are acquired from countries where the disease is endemic. In the southern United States some armadillos naturally carry the bacteria that cause leprosy, and while it is possible to acquire the disease from an armadillo the risk is very low. Hemorrhagic fevers In 2015 there were no reported cases of hemorrhagic fever in Halton, and one case in all of Ontario. Hemorrhagic fevers include a number of different viruses from several families, including Filoviridae (e.g. Ebola and Marburg), bunyaviruses (e.g. Rift Valley fever virus), arenaviruses (e.g. Lujo virus), and flaviviruses (e.g. Dengue virus). Symptoms of viral hemorrhagic fevers may include rapid onset of fever, bleeding under the skin, vomiting blood, blood in stool, bleeding from the nose and coughing up blood. In severe cases viral hemorrhagic fever can be 2015 Halton Region Infectious Disease Report 44 fatal. While dengue hemorrhagic fever is reportable, the milder, more common illness dengue fever is not reportable. Modes of transmission of viral hemorrhagic fevers vary depending on the virus. Most of the viruses that cause hemorrhagic fevers are transmitted to humans through animal or insect hosts. Ebola and Marburg are transmitted through direct contact with infected bodily fluids (such as blood or semen), while dengue is transmitted through the bite of a mosquito, similar to malaria. Tularemia There were no reported cases of tularemia reported in Halton in 2015, and one case in all of Ontario. Tularemia is caused by the bacterium Francisella tularensis. The disease is found in several wild and domestic animals, including rabbits, as well as certain insects. Humans can contract the infection in numerous ways including bites from infected ticks, eating infected undercooked meat, handling infected animals, drinking contaminated water and inhaling dust from contaminated soil. Symptoms of tularemia typically begin within 3-5 days of exposure to the bacteria, and include fever, chills, muscle pain and headache. Various other symptoms may also be present, including skin ulcers at the site of infection, swollen lymph nodes, conjunctivitis (pink eye), sore throat or tonsillitis, vomiting or diarrhea, as well as cough, chest pain and difficulty breathing. Similar to Q fever, it has been noted that tularemia has the potential to be used in bioterrorism due to the way that it can spread through aerosolized particles. Yellow fever In 2015 there were no reported cases of yellow fever in Halton, and one case in all of Ontario. Yellow fever is an acute illness that typically occurs within 3-6 days of becoming infected with the virus from the bite of a mosquito infected with the yellow fever virus. Symptoms include fever, headache, nausea or vomiting, muscle pain, loss of appetite, and jaundice. Serious cases can progress to hemorrhagic symptoms (such as vomiting blood, or bleeding gums and nose) and can be fatal. Yellow fever virus is not endemic to Ontario, and cases reported in Ontario are travel acquired or among those who immigrated to Canada from endemic countries, including areas of Africa and Latin America. Reservoirs of the virus include humans, monkeys and other vertebrates. Yellow fever is vaccine-preventable, and the vaccine is recommended for those travelling to countries where there is a risk of yellow fever. Rabies The last reported case of human rabies infection in Ontario occurred in 2012. Rabies is a viral disease that is transmitted through the bite of a rabid animal. Early symptoms of rabies include fever, headache, and malaise. Later symptoms include anxiety, confusion, excitation, increased salivation, hallucinations and paralysis. People with rabies typically die within days of the onset of these symptoms. A rabies vaccine is available for anyone who has 2015 Halton Region Infectious Disease Report 45 been exposed to animals with rabies or who may be at high risk of contact with rabid animals, which can effectively provide immunity to rabies before or soon after exposure to the virus. In Canada, common sources of rabies are raccoons, skunks, foxes, bats, and coyotes. Ontario has a highly successful rabies eradication program, where flavoured baits containing rabies vaccine are distributed in certain areas of the province to immunize the wild animals that eat them. In 2015, the first reported case of rabies in a raccoon in ten years was reported in Hamilton. In response, the Ontario government distributed rabies vaccine baits around the Hamilton area. For more information, see www.ontario.ca/page/rabies.10 Psittacosis/ornithosis The last reported case of psittacosis/ornithosis occurred in Ontario in 2011. Psittacosis/ornithosis is a disease caused by the bacteria Chlamydophila psittaci. The bacteria are carried by wild and domestic birds, and humans can become infected by inhaling dust from dried faeces or other secretions from infected birds. Person-to-person transmission is rare. Symptoms typically begin within 1-4 weeks of exposure to the bacteria, and can include fever, headache, light sensitivity, muscle pain and cough. In serious cases, inflammation of the brain, heart muscle or walls of veins can occur. Anthrax There have been no reported cases of anthrax in humans in Ontario since 1990. As anthrax is a rare and severe disease, a single case of non-travel related anthrax in Ontario would be considered an outbreak. Anthrax is caused by the bacterium Bacillus anthracis. The main reservoirs of anthrax are livestock and wild animals, and anthrax spores can be found in soil. The last positive case of anthrax in animals in Ontario was in 2006. Anthrax has been known to be used as a bioterrorism agent, and every case should be followed up to determine exposure and whether or not the case was the result of bioterrorism. Anthrax presents clinically in three different ways. Cutaneous anthrax is the most common form of anthrax infection, and occurs when anthrax spores get into the skin through a cut or scrape. Symptoms of cutaneous anthrax include a sore at the site, which may form a black ulcer, as well as fever, malaise and headache. Inhalation anthrax occurs when anthrax spores are inhaled. Early stages of inhalation anthrax may involve sweats, cough, malaise, nausea or vomiting. This is followed later by respiratory distress and shock, and has a very high mortality rate. Gastrointestinal anthrax occurs when anthrax spores are ingested. Symptoms include vomiting, abdominal pain and gastrointestinal bleeding. Lassa fever No cases of Lassa fever have ever been reported in Ontario. Lassa fever is a disease caused by the Lassa virus, and is endemic to areas of Africa including Guinea, Liberia, Nigeria and Sierra Leone. The virus is transmitted to humans through direct contact with or inhaling particles of faeces of infected wild rodents. It can also be sexuallytransmitted, or spread from person-to-person via exposure to blood and other bodily fluids of infected individuals. 2015 Halton Region Infectious Disease Report 46 Symptoms of Lassa fever appear within 6-21 days of becoming infected with the virus, and can include mild symptoms such as fever, headache, malaise and weakness. Many people do not experience any symptoms. In some people, more serious symptoms can occur such as vomiting, pain in the chest and abdomen, bleeding (in the eyes or nose), and organ failure resulting in death. Hantavirus pulmonary syndrome There have been no human cases of hantavirus pulmonary syndrome reported in Ontario since the disease became reportable in 2001. Humans can become infected with hantavirus by inhaling or coming in direct contact with the virus in the urine or faeces of infected rodents, or by being bitten by an infected rodent. Hantavirus has been found in deer mice and voles in Ontario. Hantavirus pulmonary syndrome presents as a flu-like illness, which progresses rapidly to more serious symptoms including a drop in blood pressure, fluid-filled lungs and respiratory failure. The case fatality rate of hantavirus pulmonary syndrome is 35-50%. Plague The last reported human case of the plague in Canada occurred in 1939. A single case of the plague in Canada would constitute an outbreak. The plague is caused by the bacteria Yersinia pestis, The plague is endemic in many places throughout the world, including areas of Africa, Europe, North and South America and Asia. Yersinia pestis is considered a potential bioterrorism agent, and therefore it is important to investigate plague cases to determine whether bioterrorism is a possible source of exposure. The plague can present in three different forms. Bubonic plague is transmitted via the bite of an infected flea or by handling the tissues of an infected animal. Symptoms of bubonic plague include fever and swelling of the lymph nodes. Left untreated, the case fatality of bubonic plague is around 50%. Pneumonic plague is a serious lung infection that occurs when bacteria from an infected person or animal is inhaled. If left untreated, pneumonic plague can result in death. All other forms of plague are referred to as septicaemic plague, which occurs when the Yersinia pestis bacteria spread through the blood stream to other parts of the body, and can be fatal if not treated. 2015 Halton Region Infectious Disease Report 47 Other reportable infectious diseases In addition to the various categories of infectious diseases presented in this report, there were an additional 64 cases of other reportable diseases (meningitis/encephalitis, group A streptococcal disease, tuberculosis) reported to the Halton Region Health Department in 2015, accounting for 3% of all reportable diseases in Halton. There were no cases of Creutzfeld-Jakob disease, acute flaccid paralysis, or severe acute respiratory syndrome reported in Halton in 2015. Figure 26: Other reportable diseases compared to previous five-year average, Halton residents, 2015 and 2010-2014. Source: Integrated Public Health Information System [2009-2015], extracted April 20, 2016. *Includes primary viral and unspecified encephalitis; encephalitis/meningitis; bacterial, other, and viral meningitis 2015 Halton Region Infectious Disease Report 48 Encephalitis and meningitis In 2015, there were 35 reported cases of encephalitis and/or meningitis reported in Halton, accounting for less than 2% of all reportable diseases in Halton in 2015. Encephalitis is an inflammation of the brain. There are many different agents that can cause encephalitis, many of which are viruses. Symptoms of encephalitis include sudden fever, headache, vomiting, sensitivity to light, stiff neck and back, confusion, drowsiness, unsteady gait, and irritability. Loss of consciousness, poor responsiveness, seizures, muscle weakness, sudden severe dementia, memory loss, withdrawal from social interaction, or impaired judgement may also occur. Meningitis is an inflammation of the membranes (called meninges) that surround the brain and spinal cord. Meningitis may be caused by many different viruses and bacteria, or by diseases that can cause inflammation of the tissues of the body without infection. Symptoms of meningitis, which may appear suddenly, often include high fever, severe and persistent headache, stiff neck, nausea and vomiting, as well as changes in behaviour such as confusion, sleepiness, and difficulty waking up. In infants, symptoms of meningitis may include irritability or tiredness, poor feeding, and fever. While fluctuations are expected due to the small number of cases reported on a year-to-year basis, the age-standardized incidence rates of encephalitis/meningitis combined have been steady in Ontario and Halton since 2010 (Figure 27). In 2015, the age-standardized incidence rate for meningitis/encephalitis was similar in Halton and Ontario. Figure 27: Encephalitis and meningitis combined* crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015. Sources: Integrated Public Health Information System [2006-2015], extracted April 20, 2016; Population Estimates, IntelliHEALTH, Ontario Ministry of Health and Long-Term Care [2015], extracted March 21, 2015. Ontario data: Ontario Ministry of Health and Long-Term Care, Integrated Public Health System database, extracted by Public Health Ontario [January 22, 2016]. *Includes primary viral and unspecified encephalitis; encephalitis/meningitis; bacterial, other, and viral meningitis 2015 Halton Region Infectious Disease Report 49 Invasive group A streptococcal disease In 2015 there were 17 reported cases of invasive group A streptococcal disease in Halton (iGAS), accounting for approximately 1% of all reportable diseases in Halton. iGAS disease is caused by Streptococcus pyogenes, which is a type of bacteria that commonly infects the skin and mucous membranes, causing strep throat, impetigo and other relatively mild infections. When these bacteria infect body sites that are normally sterile, such as blood (bacteraemia), cerebrospinal fluid (meningitis), and synovial fluid/joints, the disease is classified as iGAS disease. Serious cellulitis, necrotizing fasciitis (flesh-eating disease), and streptococcal toxic shock syndrome are forms of iGAS disease. The disease is generally spread via person-to-person contact including: droplet spread when an infected person coughs or sneezes, direct contact with mucus from the nose or throat of an infected person, or through contact with infected skin sores. iGAS disease typically occurs more frequently in the late winter and spring in Ontario. Halton’s age-standardized rates for iGAS have been fairly similar to Ontario, but show greater variability due to the small number of cases. Figure 28: Invasive Group A streptococcal disease crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015. Sources: Integrated Public Health Information System [2006-2015], extracted April 20, 2016; Population Estimates, IntelliHEALTH, Ontario Ministry of Health and Long-Term Care [2015], extracted March 21, 2015. Ontario data: Ontario Ministry of Health and Long-Term Care, Integrated Public Health System database, extracted by Public Health Ontario [January 22, 2016]. 2015 Halton Region Infectious Disease Report 50 Tuberculosis In 2015, there were 12 reported cases of tuberculosis in Halton. Tuberculosis is a mycobacterial disease that is a major cause of disability and death, especially among those in developing countries. About 10% of those initially infected will eventually develop active tuberculosis disease, half of those developing the disease during the first two years following infection. 90% of untreated infected individuals will never develop active tuberculosis. Only active cases of tuberculosis are included in this report. Worldwide, industrialized countries have seen downwards trends in mortality and morbidity due to tuberculosis for many years, however, since the mid-1980s, population groups with a high prevalence of HIV infection have experienced increasing rates of tuberculosis. Worldwide, 1-2% of all tuberculosis cases involve a multi-drug resistant strain. In some countries, such as parts of China, India, and Russia, multi-drug resistant tuberculosis is a major public health issue. The ten-year trend in incidence of active tuberculosis has remained fairly steady in Ontario, but has fluctuated for Halton (Figure 29). Age-standardized rates of infectious tuberculosis in Halton have remained consistently lower than Ontario. The fluctuations in rates of tuberculosis are expected as the number of cases in the population is low. Figure 29: Tuberculosis crude and age-standardized incidence rates (per 100,000), Halton residents compared to Ontario, 2006-2015. Sources: Integrated Public Health Information System [2006-2015], extracted April 20, 2016; Population Estimates, IntelliHEALTH, Ontario Ministry of Health and Long-Term Care [2015], extracted March 21, 2015. Ontario data: Ontario Ministry of Health and Long-Term Care, Integrated Public Health System database, extracted by Public Health Ontario [January 22, 2016]. 2015 Halton Region Infectious Disease Report 51 Acute flaccid paralysis There were no reported cases of acute flaccid paralysis in Halton in 2015, and three cases in all of Ontario. The last reported case of acute flaccid paralysis in Halton was in 2014. Acute flaccid paralysis can be caused by a number of different pathogens, including enteroviruses (including the virus that causes polio), adenoviruses, West Nile Virus, Campylobacter, and botulism. As poliovirus can cause acute flaccid paralysis, it is important to rule out this virus as the causative agent in order to maintain Canada’s status as polio-free. A single case of polio in Canada would be considered a public health emergency (see section of this report on Polio). In Canada, acute flaccid paralysis is most often caused by Guillain-Barré Syndrome. Signs and symptoms of acute flaccid paralysis include rapid onset of weakness or paralysis, in children less than 15 years old (without other causes like trauma). Acute flaccid paralysis associated with polio is typically asymmetric, often involving one leg or one arm only. Acute flaccid paralysis associated with Guillain-Barré Syndrome can be symmetrical. Creutzfeldt-Jakob disease There were no reported cases of Creutzfeldt-Jakob disease (CJD) in Halton in 2015, and eight cases in all of Ontario. The last reported case of CJD in Halton was in 2014. CJD is a rare, degenerative brain disorder. It belongs to a group of diseases called transmissible spongiform encephalopathies, or prion diseases. There are three major forms of classic CJD. The most common is sporadic CJD, the exact cause of which is not known. Familial CJD is associated with a family history of the diseases. Iatrogenic (acquired) CJD occurs when the infection is spread from a person with CJD to another person through surgical or medical treatment, and is very rare. Variant CJD is a fourth, rare form of the disease which has been linked to exposure to cattle with Bovine Spongiform Encephalopathy (often referred to as “mad cow”). Signs and symptoms of CJD include confusion, dementia, difficulty walking, loss of control of body movements and loss of speech. CJD is fatal. Severe Acute Respiratory Syndrome The last reported case of Severe Acute Respiratory Syndrome (SARS) in Canada was in 2003, and the last reported case worldwide was in China in 2004. SARS is a viral respiratory illness caused by a coronavirus. The disease was first reported in China in 2003. By the summer of 2003, major outbreaks occurred in Canada, the Guangdong Province of China, Hong Kong, Taiwan, Singapore and Vietnam. There has been no evidence of the virus in humans since 2004. SARS is transmitted from person-to-person by close contact, such as when an infected person coughs or sneezes, or through contact with infected bodily fluids. Symptoms of SARS typically begin within 2-10 days of exposure to the virus, and may include malaise, fever, cough, shortness of breath, diarrhea, pneumonia, and acute respiratory distress syndrome (life threatening fluid build-up in the lungs). 2015 Halton Region Infectious Disease Report 52 Part III: Infectious diseases and the social determinants of health Social determinants of health reflect the social and physical conditions where people live, learn, work, and play. These conditions can influence an individual’s overall health, as well as their risk of infection and disease. There is a clear relationship between infectious diseases and the social determinants of health; however, sometimes this relationship is complex, and best understood by exploring specific examples such as sexually-transmitted infections (STIs) and tuberculosis. Sexually-transmitted infections (STIs) Individual behaviours such as inconsistent condom use and multiple sexual partners clearly influence an individual’s risk of developing an STI. However, these behaviours can be influenced by the social determinants of health. For example, someone who is living in low income, has unsafe or unstable housing, or has limited social supports often has fewer opportunities to make choices that decrease their risk of infection or disease. Access to accurate and reliable health information, as well as the availability of low cost/no cost STI prevention, screening, and treatment are also important because these supports can create opportunities for individuals to make choices that reduce their risk of contracting or transmitting an STI. Tuberculosis Tuberculosis is another example of an infectious disease which can be influenced by the social determinants of health. For example, an individual can be at a greater risk of developing tuberculosis if they are malnourished or experiencing homelessness. The social determinants of health also contribute to physical environments where tuberculosis is more likely to be transmitted, such as crowded and inadequately ventilated housing. Infectious diseases and the social determinants of health in Halton Due to the influence of the social determinants of health, the burden of infectious disease is not evenly distributed across the population. In 2015, the age-standardized incidence rate of reportable infectious diseases in Halton decreased as neighbourhood income increased. These differences were statistically significant when comparing the low income group to the middle and high income groups. Halton residents in the lowest income group were 2.4 times more likely to have a reportable infectious disease compared to those in the highest income group (Figure 30). 2015 Halton Region Infectious Disease Report 53 Figure 30: Age-standardized incidence rates (per 100,000), by neighbourhood income group, Halton Region, 2015 Sources: Integrated Public Health Information System [2006-2015], extracted April 20, 2016. Statistics Canada, 2011 Census of Population, Statistics Canada Catalogue no. 98-311-XCB2011018. Statistics Canada. 2013. Canadian National Household Survey (NHS) Profile. 2011 National Household Survey. Statistics Canada Catalogue no. 99-004-XWE. Ottawa. Released September 11, 2013. There is a clear relationship between income and infectious disease in Halton. However, income is only one determinant of health and is often linked to other determinants of health. In order to effectively reduce the incidence and prevalence of infectious diseases in Halton, the role that income and other determinants of health play must be considered. Addressing the root causes of infectious diseases includes improving the social and physical environments where people live, learn, work, and play, so that all Halton residents have the opportunity to make choices that allow them to achieve their best possible health. 2015 Halton Region Infectious Disease Report 54 Part IV: Outbreak investigations Halton Region Health Department staff investigate outbreaks under the mandate to “decrease or eliminate the risks to health presented by infectious diseases” as outlined in the Health Protection and Promotion Act.1 Although many infectious disease investigations involve single sporadic cases (i.e. can’t be linked to other cases), contaminated food or water, or person-toperson contact can result in clusters of illness affecting large numbers of people. Some outbreaks have required significant Halton Region Health Department resources, especially those of longer duration. All institutional enteric and respiratory outbreaks are reportable to the Halton Region Health Department (HRHD) regardless of whether or not the specific disease is known or reportable. Outbreaks of enteric illness in institutions are most frequently caused by viruses such as norovirus, however, bacteria and other pathogens may cause outbreaks as well. Outbreaks of respiratory infections in institutions are typically caused by a variety of respiratory viruses such as influenza A and B, rhinovirus, coronavirus, respiratory syncytial virus (RSV) and other viruses. Examples of bacteria that cause respiratory outbreaks in institutions include Chlamydia pneumonia, Legionella, and Mycoplasm pneumoniae (atypical pneumonia). Since each outbreak requires its own case definition, health unit staff collaborate with the facility to develop a case definition based on the outbreak’s characteristics and any agent identified through laboratory testing. Health unit staff also provide ongoing support to the facility during the outbreak investigation to ensure that infection prevention and control measures are used to minimize the duration of outbreaks and to minimize the impact of the outbreak on both staff and residents. Public health units in Ontario are required to report both confirmed and suspect respiratory and enteric outbreaks into the Integrated Public Health Information System (iPHIS). The Provincial Case Definitions3 section of the 2015 Infectious Disease Protocol provides definitions for confirmed and suspect enteric and respiratory outbreaks. There were a total of 130 outbreaks investigated by the Halton Region Health Department in 2015. 2015 Halton Region Infectious Disease Report 55 Respiratory outbreaks In 2015, there were a total of 74 respiratory outbreaks investigated by the Halton Region Health Department, accounting for 57% of all (both respiratory and enteric) outbreaks reported. Agent In 2015, the most common agents involved in respiratory outbreaks investigated by the HRHD were influenza A (45%) and rhinovirus (23%). The higher number of influenza A outbreaks investigated in 2015 compared to the previous 5-year average is consistent with a high amount of flu activity observed in Halton and throughout Ontario during the 2014-2015 flu season. Figure 31: Respiratory outbreaks investigated in Halton compared to previous five-year average, by agent, 2015 and 2010-2014. Source: Integrated Public Health Information System [2015], extracted April 12, 2016; Integrated Public Health Information System [2010-2014], extracted May 2, 2016. Location In 2015, the majority of respiratory outbreaks investigated by the HRHD involved long-term care homes (69%), followed by retirement homes (22%), unregulated or special homes (5%), hospitals (3%), and child care centres (1%) (Figure 32). Figure 32: Respiratory outbreaks investigated in Halton, by location, 2015. Source: Integrated Public Health Information System [2015], extracted April 12, 2016; Integrated Public Health Information System [2010-2014], extracted May 2, 2016. 2015 Halton Region Infectious Disease Report 56 Seasonal variation In 2015, the majority of outbreaks investigated in Halton were in the winter months, particularly January (Figure 33). Five of the outbreaks reported in 2015 had an onset date in December 2014 (not shown). Figure 33: Respiratory outbreaks investigated in Halton, by month of onset, 2015. Integrated Public Health Information System [2015], extracted April 12, 2016. Outbreak duration The duration of outbreaks varied from approximately one week to up to five weeks or longer. The most common outbreak duration was 1-2 weeks (46%) (Figure 34). Figure 34: Respiratory outbreaks investigated in Halton, by duration, 2015. Integrated Public Health Information System [2015], extracted April 12, 2016. 2015 Halton Region Infectious Disease Report 57 Number of cases investigated Of the total 977 people who became ill with a respiratory illness, 755 (77%) were clients and 222 (23%) were staff of the affected premises. In total, 9,553 clients and 10,911 staff were “at risk of becoming ill” because of an outbreak in their facilities, and subject to increased control procedures (Table 2). Table 2: Total number of clients and staff who were at risk and who were ill, by location of the outbreak, respiratory outbreaks, Halton Region, 2015. Location of outbreak Clients Staff At risk Ill At risk Ill Long-term care home 7424 499 9696 182 Retirement residence 1437 168 829 35 Unregulated/special homes 547 66 267 4 Child care 80 12 16 1 Hospital 65 10 103 0 Total 9553 755 10911 222 Source: Integrated Public Health Information System [2015], extracted April 19, 2016. Enteric outbreaks In 2015, there were a total of 56 enteric outbreaks investigated by the Halton Region Health Department, accounting for 43% of all outbreaks (respiratory and enteric) reported. Agent In 2015, the agent was unknown for more than half (63%) of enteric outbreaks. For outbreaks where the agent was known, norovirus was the most common agent (32%), followed by calcivirus/norovirus (4%) and adenovirus (2%) (Figure 35). Figure 35: Enteric outbreaks investigated in Halton compared to previous five-year average, by agent, 2015 and 2010-2014. Source: Integrated Public Health Information System [2010-2015], extracted April 18, 2016; Integrated Public Health Information System [2010-2014], extracted May 2, 2016. 2015 Halton Region Infectious Disease Report 58 Location In 2015, the majority of enteric outbreaks investigated by the HRHD include child care centres (55%), followed by long-term care homes (27%), retirement residence (13%), within the community (4%), and hospitals (2%) (Figure 36). Figure 36: Enteric outbreaks investigated in Halton compared to previous five-year average, by location, 2015 and 2010-2014. Source: Integrated Public Health Information System [2010-2015], extracted April 18, 2016; Integrated Public Health Information System [2010-2014], extracted May 2, 2016. Seasonal variation In 2015, the majority of outbreaks investigated in Halton were in the winter and early spring. The number of outbreaks peaked in the months of February and March (11 and 12 outbreaks, respectively) (Figure 37). Figure 37: Enteric outbreaks investigated in Halton, by month of onset, 2015. Source: Integrated Public Health Information System [2015], extracted April 18, 2016. 2015 Halton Region Infectious Disease Report 59 Outbreak duration The duration of outbreaks varied from less than one week to up to five weeks or longer. Approximately 42% of enteric outbreaks lasted less than two weeks and 9% lasted four weeks or longer (Figure 34). Figure 38: Enteric outbreaks investigated in Halton*, by duration, 2015. Source: Integrated Public Health Information System [2015], extracted April 18, 2016. *excludes community outbreaks Number of cases investigated Of the total 1,213 people who became ill, 940 (77%) were clients and 273 (23%) were staff of the affected premises. In total, 5,063 clients and 3,143 staff were “at risk of becoming ill” because of an outbreak in their facilities, and subject to increased control procedures (Table 3). Table 3: Total number of clients and staff who were at risk and who were ill, by location of the outbreak, enteric outbreaks, Halton Region, 2015 Location of outbreak Clients Staff At risk Ill At risk Ill Long-term care home 1978 290 2308 108 Retirement residence 649 121 315 34 Unregulated/special homes 0 0 0 0 Child care 2388 515 470 127 Hospital 44 10 50 4 Community 4 Total 5063 940 3143 273 Source: Integrated Public Health Information System [2015], extracted April 21, 2016. 2015 Halton Region Infectious Disease Report 60 Conclusion Infectious diseases are an important cause of illness and death throughout Canada, and health units across Ontario are mandated under the Health Protection and Promotion Act to work to prevent and reduce the burden of illness due to infectious diseases in the population. Reports of infectious diseases in the population are important for monitoring the health of the community, and help to fulfil the Health Department’s mandate to conduct disease surveillance. Results of this report will be used by the Halton Region Health Department to inform program planning and the delivery of health services for the Halton community. For more information on infectious diseases in Halton, as well as other health statistics, please refer to the Halton Health Statistics website. 2015 Halton Region Infectious Disease Report 61 References 1. Health Protection and Promotion Act, RSO 1990, c H.7. Retrieved February 2016 from https://www.ontario.ca/laws/statute/90h07. 2. O. Reg. 559/91: Specification of Reportable Diseases, Health Protection and Promotion Act, RSO 1990, c H.7. Retrieved February 2016 from https://www.ontario.ca/laws/regulation/910559 3. Infectious Disease Protocol, 2015, Appendix B – Provincial Case Definitions. Ontario Public Health Standards. Retrieved February 2016 from http://www.health.gov.on.ca/en/pro/programs/publichealth/oph_standards/infdispro.aspx 4. Infectious Disease Protocol, 2015, Appendix A – Disease-Specific Chapters. Ontario Public Health Standards. Retrieved February 2016 from http://www.health.gov.on.ca/en/pro/programs/publichealth/oph_standards/infdispro.aspx 5. Publicly Funded Immunization Schedules for Ontario – October 2015. Retrieved May 2016 from http://www.health.gov.on.ca/en/pro/programs/immunization/docs/immunization_schedule .pdf 6. Deeks et al. Prolonged pertussis outbreak in Ontario originating in an under-immunized religious community. Canada Communicable Disease Report, 40(3), 2014. 7. Public Health Notice Update - Outbreak of Cyclospora under investigation. Public Health Agency of Canada. Retrieved May 2016 from http://www.phac-aspc.gc.ca/phnasp/2015/cyclospora-eng.php 8. Monthly Infectious Disease Surveillance Report, February 2015. Public Health Ontario. Retrieved February 2016 from http://www.publichealthontario.ca/en/DataAndAnalytics/Documents/PHO_Monthly_Infect ious_Diseases_Surveillance_Report_-_February_2015.pdf 9. Guidelines for Testing and Treatment of Gonorrhea in Ontario, April 2013. Public Health Ontario. Retrieved February 2016 from http://www.publichealthontario.ca/en/eRepository/Guidelines_Gonorrhea_Ontario_2013. pdf 10. Rabies, 2016. Government of Ontario. Retrieved February 2016 from www.ontario.ca/page/rabies 11. iPHIS data caveats for Query. Public Health Ontario. Retrieved February 2016 from http://www.publichealthontario.ca 12. Query Metadata (Infectious Diseases). Public Health Ontario. Retrieved February 2016 from http://www.publichealthontario.ca 13. NHS User Guide, National Household Survey, 2011. Retrieved February 2016 from http://www12.statcan.gc.ca/nhs-enm/2011/ref/nhs-enm_guide/99-001-x2011001-eng.pdf 2015 Halton Region Infectious Disease Report 62 Appendix A: O. Reg 559/91 under the Health Protection and Promotion Act ONTARIO REGULATION 559/91 SPECIFICATION OF REPORTABLE DISEASES2 Last amendment: O. Reg. 315/13. The following diseases are specified as reportable diseases for the purposes of the Act: Acquired Immunodeficiency Syndrome (AIDS) Acute Flaccid Paralysis Amebiasis Anthrax Botulism Brucellosis Campylobacter enteritis Chancroid Chickenpox (Varicella) Chlamydia trachomatis infections Cholera Clostridium difficile associated disease (CDAD) outbreaks in public hospitals Creutzfeldt-Jakob Disease, all types Cryptosporidiosis Cyclosporiasis Diphtheria Encephalitis, including, i. Primary, viral ii. Post-infectious iii. Vaccine-related iv. Subacute sclerosing panencephalitis v. Unspecified Food poisoning, all causes Gastroenteritis, institutional outbreaks Giardiasis, except asymptomatic cases Gonorrhoea Group A Streptococcal disease, invasive Group B Streptococcal disease, neonatal Haemophilus influenzae b disease, invasive Hantavirus pulmonary syndrome Hemorrhagic fevers, including, i. Ebola virus disease ii. Marburg virus disease iii. Other viral causes Hepatitis, viral, i. Hepatitis A ii. Hepatitis B iii. Hepatitis C Influenza Lassa Fever Legionellosis Leprosy 2015 Halton Region Infectious Disease Report 63 Listeriosis Lyme Disease Malaria Measles Meningitis, acute, i. bacterial ii. viral iii. other Meningococcal disease, invasive Mumps Ophthalmia neonatorum Paralytic Shellfish Poisoning Paratyphoid Fever Pertussis (Whooping Cough) Plague Pneumococcal disease, invasive Poliomyelitis, acute Psittacosis/Ornithosis Q Fever Rabies Respiratory infection outbreaks in institutions Rubella Rubella, congenital syndrome Salmonellosis Severe Acute Respiratory Syndrome (SARS) Shigellosis Smallpox Syphilis Tetanus Trichinosis Tuberculosis Tularemia Typhoid Fever Verotoxin-producing E. coli infection indicator conditions, including Haemolytic Uraemic Syndrome (HUS) West Nile Virus Illness Yellow Fever Yersiniosis O. Reg. 559/91, s. 1; O. Reg. 205/95, s. 1; O. Reg. 129/96, s. 1; O. Reg. 381/01, s. 1; O. Reg. 432/01, s. 1; O. Reg. 81/03, s. 1; O. Reg. 96/03, s. 1; O. Reg. 365/06, s. 1; O. Reg. 304/08, s. 1; O. Reg. 315/13, s. 1. Omitted (revokes other Regulations). O. Reg. 559/91, s. 2. 2015 Halton Region Infectious Disease Report 64 Appendix B: Data notes and limitations Definitions Dissemination areas (DAs) are small geographic units with a population of 400 to 700 persons. DAs are the smallest standard geographic area for which all census data are disseminated. All of Canada is divided into DAs. In the census year 2011, Halton Region was made up of 746 DAs. Neighbourhood income groups: The National Household Survey (NHS) indicator “in the bottom half of the Canadian distribution” was used as the bases for the neighbourhood income groups. The term neighbourhood refers to a single DA. This indicator provides the percent of households per DA who are in the bottom half of the Canadian distribution based on adjusted household income. Using this value, all of the DAs in Canada were ranked into 10 equal groups (deciles) and then categorized as low (deciles 1-3), middle (deciles 4-7) or high (deciles 8-10). When looking at Halton alone, this resulted in an unequal number of DAs in each income group since deciles are based on the national ranking. Each infectious disease case extracted from iPHIS was assigned to the appropriate DA using the provided postal code along with the postal code conversion file (2011, Postal Code Conversion File). Since the actual income of individuals is not known, and may vary from their neighbourhood income, misclassification of individuals based on their neighbourhood income instead of household income may diminish the association between income and infectious disease incidence. Approximately 11% of infectious disease records from iPHIS were not included in the income analysis due to no postal code being provided, incomplete postal codes, postal codes not matching in the PCCF file, or data being suppressed due to small response from the NHS. Data Sources Halton infectious disease data: Integrated Public Health Information System [2006-2015], extracted April 20, 2016. Ontario infectious disease data: Ontario data: Ontario Ministry of Health and Long-Term Care, Integrated Public Health System database, extracted by Public Health Ontario [January 22, 2016]. Population estimates for Halton and Ontario: Population Estimates, IntelliHEALTH, Ontario Ministry of Health and Long-Term Care [2015], extracted March 21, 2015. Population estimates by DA for income calculation: Statistics Canada, 2011 Census of Population, Statistics Canada Catalogue no. 98-311XCB2011018. Outbreak investigation data: Integrated Public Health Information System [2010-2015], extracted April 20, 2016. 2015 Halton Region Infectious Disease Report 65 Income indicator: Statistics Canada. 2013. Canadian National Household Survey (NHS) Profile. 2011 National Household Survey. Statistics Canada Catalogue no. 99-004-XWE. Ottawa. Released September 11, 2013. Postal code conversion file: Statistics Canada, 2011 Census of Population, Postal Code Conversion File (PCCF). Ottawa. Released July 20 2011. iPHIS data extraction logic Diagnosis status date was used for AIDS cases Encounter date was used for HIV cases Diagnosis date was used for tuberculosis cases Accurate episode date was used for all other diseases Diagnosing health unit = Halton Disposition statuses containing “do not use”, “entered in duplicate” or “entered in error” were not included Atypical mycobacterial infection tuberculosis cases were not included To obtain the total number of HIV cases, all AIDS cases classified as ‘Carrier’ or ‘Confirmed’ in iPHIS were combined For more information on data extraction logic, see Public Health Ontario’s iPHIS data caveats for Query and Metadata document.11,12 Limitations There is likely to be under-reporting of cases, as not all infected individuals may experience symptoms and/or seek medical care, so laboratory testing may not be performed for all cases. iPHIS is a dynamic disease reporting system which allows ongoing updates to data previously entered. Therefore, data in this report may differ from previous or subsequent reports and should not be compared to these reports. Case definitions of reportable diseases have changed over time, therefore trends over time should be interpreted with caution. In addition, diagnostic technology has changed over time, therefore changes over time should also be interpreted with caution as they may reflect changes in diagnostic procedures rather than true changes in incidence in the population. For more information on changes in case definitions see the Infectious Disease Protocol (Appendix B).3 Population counts by DA are only available for census years (2011 in this report). As this report included five years of data for the income analysis, to determine the denominator it was necessary to multiply the 2011 population by five, even though the population may have varied from year to year (especially in Milton). This report uses the National Household Survey income indicator, “in bottom half of the Canadian distribution”. In 2011 the voluntary National Household Survey replaced the mandatory long form census. In Halton, the global non-response rate increased from under 5% in 2006 to 23% in 2011. Because voluntary surveys are more prone to non-response bias than mandatory surveys, the NHS data may not reflect a representative sample of Halton’s 2015 Halton Region Infectious Disease Report 66 population, especially at smaller areas of geography (such as dissemination areas) and certain population groups (such as low income). Statistics Canada has warned that people with low incomes and very high incomes, Aboriginals, and recent immigrants were less likely to respond to the NHS. See the NHS user guide13 for more information. Estimates are rounded, therefore not all percentages may add up to 100%. 2015 Halton Region Infectious Disease Report 67 Appendix C: Summary table of case definitions Table 4: Summary table of provincial case definitions, adapted from the 2015 Infectious Disease Protocol (Appendix B)3 Probable Suspect Confirmed Disease Carrier case case case Acute flaccid paralysis Amebiasis Anthrax Botulism Brucellosis Campylobacter enteritis Chancroid Chicken pox (varicella) Chlamydial infections Cholera Creutzfeldt-Jakob disease, all types Cryptosporidiosis Cyclosporiasis Diphtheria Encephalitis/meningitis Giardiasis Gonorrhea (all types) Group A streptococcal disease, invasive Group B streptococcal disease, neonatal Haemophilus influenzae B disease, invasive Hantavirus pulmonary syndrome Hemorrhagic fevers Hepatitis A Hepatitis B Hepatitis C HIV AIDS Influenza Lassa fever Legionellosis Leprosy Listeriosis Lyme disease Malaria Measles Meningococcal disease, invasive 2015 Halton Region Infectious Disease Report X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X 68 Disease Mumps Opthalmia neonatorum Paralytic shellfish poisoning Paratyphoid fever Pertussis (whooping cough) Plague Poliomyelitis, acute Psittacosis/ornithosis Q fever Rabies Rubella Salmonellosis Severe Acute Respiratory Syndrome (SARS) Shigellosis Smallpox Streptococcus pneumoniae, invasive Syphilis, early congenital Syphilis Tetanus Trichinosis Tuberculosis Tularemia Typhoid fever Verotoxin producing E. coli including HUS West Nile Virus Illness Yellow fever Yersiniosis 2015 Halton Region Infectious Disease Report Probable case Suspect case X X X X X X X X X X X X X X X X X X X X X X X X Confirmed case Carrier X X X X X X X X X X X X X X X X X X X X X X X X X X X 69 Appendix D: Summary of counts and rates of reportable infectious diseases Table 5 below summarizes counts, rates, and incidence rate ratios of reportable infectious diseases in Halton with five or more cases in 2015. Counts are presented for 2015 as well as the previous five-year average (2010-2014) in Halton. Crude incidence rates are presented for Halton in 2015 and for the previous five-year average. Crude incidence rate ratios are also presented for Halton in 2015 compared to the previous 5-year average. 95% confidence intervals for the rate ratios are presented in brackets. A cell shaded in red with an up arrow (↑) indicates that 2015 had a statistically significantly higher crude rate compared to the previous five year average, a cell shaded in green with a down arrow (↓) indicates that the crude rate was statistically significantly lower in 2015, and an equals sign (=) indicates that there was no significant difference in 2015 compared to the previous five year average. Age-standardized incidence rates (ASIRs) are presented for Halton and Ontario. Age-standardized rate ratios are also presented for Halton compared to Ontario in 2015. 95% confidence intervals for the rate ratios are presented in brackets. An up arrow (↑) indicates that Halton had a statistically significantly higher age-standardized rate compared to Ontario, a down arrow (↓) indicates that the age-standardized rate was statistically significantly lower in Halton, and an equals sign (=) indicates that there was no significant difference in 2015 between Halton and Ontario. Table 5: Summary of counts, crude rates, crude rate ratio, age-standardized rates, and age-standardized rate ratio for reportable infectious diseases, Halton and Ontario, 2010-2015. Halton # of Crude rate ratio Halton crude rate Halton Ontario Age-standardized cases (Halton 2015 vs Disease 2015 2015 rate ratio (Halton vs. 2010-2014 2010-14 2010-14 ASIR ASIR Ontario, 2015) 2015 2015 average) average average Vaccine-preventable diseases Influenza (calendar year) 398 242 71 45 1.6 (1.3-1.8) (↑) 61 58 1.1 (1.0-1.2) (=) Streptococcus pneumoniae 20 35 3.6 6.7 0.5 (0.3-0.9) (↓) 2.9 5.8 0.5 (0.3-0.8) (↓) Pertussis (whooping cough) 13 9 2.3 1.6 1.4 (0.6-3.3) (=) 2.4 6.3 0.4 (0.2-0.7) (↓) Chickenpox (varicella) 11 14 1.8 2.6 0.7 (0.3-1.5) (=) NA NA NA 2015 Halton Region Infectious Disease Report 70 Halton # of cases Disease Hepatitis B Halton crude rate 2015 2010-14 average 2015 6 4 1.1 2010-14 average 0.8 Crude rate ratio (Halton 2015 vs 2010-2014 average) Halton 2015 ASIR Ontario 2015 ASIR Age-standardized rate ratio (Halton vs. Ontario, 2015) 1.4 (0.4-5.0) (=) 1.1 0.6 1.9 (0.8-4.7) (=) Food- and water-borne diseases Salmonellosis 123 104 22 20 1.1 (0.9-1.4) (=) 23 22 1.0 (0.9-1.2) (=) Campylobacter enteritis 123 137 22 26 0.8 (0.7-1.1) (=) 22 24 0.9 (0.8-1.1) (=) Giardiasis 46 49 8.2 9.3 0.9 (0.6-1.3) (=) 8.7 11 0.8 (0.6-1.1) (=) Amebiasis 25 17 4.5 3.3 1.3 (0.7-2.5) (=) 4.8 6.0 0.8 (0.5-1.2) (=) Cyclosporiasis 17 6 3.0 1.2 2.5 (1.0-6.3) (↑) 3.0 1.9 1.6 (0.9-2.7) (=) Yersiniosis 13 9 2.3 1.7 1.3 (0.6-3.1) (=) 2.3 1.8 1.3 (0.7-2.3) (=) Verotoxin-producing E. coli with HUS 8 5 1.4 0.9 1.6 (0.5-5.1) (=) 1.5 1.5 1.0 (0.5-2.1) (=) Cryptosporidiosis 6 8 1.1 1.5 0.7 (0.2-2.0) (=) 1.4 3.3 0.4 (0.2-1.0) (↓) Legionellosis 5 8 0.9 1.5 0.6 (0.2-1.8) (=) 0.7 0.7 1.0 (0.4-2.4) (=) Shigellosis 5 7 0.9 1.4 0.6 (0.2-2.0) (=) 0.9 2.0 0.5 (0.2-1.1) (=) Sexually-transmitted and blood-borne infections Chlamydia 916 799 163 151 1.1 (1.0-1.2) (=) 203 328 0.6 (0.6-0.7) (↓) Gonorrhoea 117 79 21 15 1.4 (1.1-1.9) (↑) 26 50 0.5 (0.4-0.6) (↓) Hepatitis C 99 95 18 18 1.0 (0.7-1.3) (=) 19 30 0.6 (0.5-0.8) (↓) Syphilis 27 41 4.8 7.8 0.6 (0.4-1.0) (↓) 5.3 12.0 0.4 (0.3-0.7) (↓) HIV 11 14 2.0 2.7 0.7 (0.3-1.6) (=) 2.4 6.0 0.4 (0.2-0.8) (↓) 2015 Halton Region Infectious Disease Report 71 Halton # of cases Disease 2015 2010-14 average Halton crude rate 2015 2010-14 average Crude rate ratio (Halton 2015 vs 2010-2014 average) Halton 2015 ASIR Ontario 2015 ASIR Age-standardized rate ratio (Halton vs. Ontario, 2015) Zoonotic, exotic, and vector-borne diseases Lyme disease 10 5 1.8 1.0 1.8 (0.6-5.2) (=) 1.7 2.7 0.6 (0.3-1.2) (=) Malaria 5 5 0.9 0.9 0.9 (0.3-3.3) (=) 0.6 1.3 0.5 (0.2-1.3) (=) Other reportable infectious diseases Encephalitis/meningitis** 35 37 6.2 7.0 0.9 (0.6-1.4) (=) 6.7 5.3 1.3 (0.9-1.8) (=) Invasive group A streptococcal disease 17 17 3.0 3.3 0.9 (0.5-1.8) (=) 3.1 3.8 0.8 (0.5-1.4) (=) Tuberculosis 12 15 2.1 2.9 0.7 (0.3-1.6) (=) 1.9 4.2 0.4 (0.2-0.8) (↓) Sources: Integrated Public Health Information System [2006-2015], extracted April 20, 2016; Population Estimates, IntelliHEALTH, Ontario Ministry of Health and Long-Term Care [2015], extracted March 21, 2015. Ontario data *Excludes early congenital syphilis **Includes primary viral and unspecified encephalitis; encephalitis/meningitis; bacterial, other, and viral meningitis 2015 Halton Region Infectious Disease Report 72 Table 6: Summary of counts of rare reportable diseases in Halton, 2010-2015 summarizes counts of rare reportable diseases in Halton (diseases with less than five cases in 2015), compared to the five-year average (2010-2014). For diseases with zero cases in Halton in 2015, the date of the last reported case is also presented. Note that depending on rarity of the disease and availability of data, the last reported case date may be for Halton, Ontario, Canada, or worldwide (location listed in brackets). Table 6: Summary of counts of rare reportable diseases in Halton, 2010-2015 Halton # of cases 2010Disease Year of last reported case 2015 2014 average Vaccine-preventable diseases Mumps 2 3 2015 (Halton) Measles 1 2 2015 (Halton) Invasive meningococcal disease 0 1 2014 (Halton) Invasive Haemophilus influenzae B 0 <1 2011 (Halton) disease Tetanus 0 <1 2011 (Halton) Rubella 0 0 2005 (Halton) Diphtheria 0 0 1995 (Ontario) Polio 0 0 1977 (Canada) Declared eradicated worldwide in Smallpox 0 0 1979 Food- and water-borne diseases Listeriosis 2 2 2015 (Halton) Typhoid fever 2 1 2015 (Halton) Hepatitis A 1 4 2015 (Halton) Paratyphoid fever 0 3 2014 (Halton) Botulism 0 <1 2012 (Halton) Cholera 0 0 2008 (Halton) No cases in Halton in last 10 years† Trichinosis 0 0 Paralytic shellfish poisoning 0 0 2014 (Ontario) Sexually-transmitted and blood-borne infections AIDS 1 3 2015 (Halton) Chancroid 0 0 1997 (Ontario) Neonatal Neonatal group B streptococcal 2 1 2015 (Halton) disease Early congenital syphilis 1 <1 2015 (Halton) Congenital rubella syndrome 0 0 2009 (Ontario) No cases in Halton in last 10 Opthalmia neonatorum 0 0 years* Zoonotic, exotic, and vector-borne diseases West Nile Virus illness 1 9 2015 (Halton) Q fever 0 1 2013 (Halton) Leprosy 0 <1 2011 (Halton) Brucellosis 0 0 2009 (Halton) 2015 Halton Region Infectious Disease Report 73 No cases in Halton in last 10 years† No cases in Halton in last 10 years† No cases in Halton in last 10 years† 2012 (Ontario) 2011 (Ontario) 1990 (Ontario) No cases have ever been reported Lassa fever 0 0 in Ontario No cases have been reported in Hantavirus pulmonary syndrome 0 0 Ontario since disease became reportable in 2001 Plague 0 0 1939 (Canada) Other reportable infectious diseases Acute flaccid paralysis 0 <1 2014 (Halton) Creutzfeldt-Jakob disease 0 <1 2014 (Halton) Severe acute respiratory syndrome 2003 (Halton & Canada), 2004 0 0 (SARS) (worldwide) Hemorrhagic fevers Tularemia Yellow fever Rabies Psitticosis/ornithosis Anthrax 0 0 0 0 0 0 0 0 0 0 0 0 Sources: Integrated Public Health Information System [2010-2015], Infectious Disease Protocol, 2015, Appendix B – Provincial Case Definitions. Ontario Public Health Standards. Retrieved February 2016 from http://www.health.gov.on.ca/en/pro/programs/publichealth/oph_standards/infdispro.aspx † There are still cases reported in Ontario, however, there have been no cases reported in Halton in the last ten years of data available in iPHIS. 2015 Halton Region Infectious Disease Report 74 1 Health Protection and Promotion Act, RSO 1990, c H .7. R etrieved F ebru ar y 2016 fro m https://www.o ntar io.ca/laws/statute/90h 07. 2 O. R eg. 559/91: Sp ecification of Rep ortab le Diseases, H ealth Protection and Promotion Act , RSO 1990, c H .7. R etrieved F ebru ar y 2016 fro m https://www.ontar io.ca/laws/r egulation /910559 3 Infectiou s Disease Protoco l, 2015, Append ix B – Provin cial C ase D efin itions. Ontar io Public H ealth Stand ard s. Retrieved F ebru ar y 2016 from http://www.h ealth.gov.o n.ca/en/pro/p rogr am s/pub lichealth/o ph_stan dard s/infdispro.aspx 4 Infectiou s Disease Protoco l, 2015, Append ix A – Disease- Sp ecific Chapt er s. Ontario Public Health Stan dard s. Retr iev ed F ebru ar y 2016 from http://www.health.gov.on.ca/en /pro/progr am s/pub lichealth /oph _st andards/infdispro .asp x 5 Publicly Fund ed Immun izat ion Sch edules for Ontario – Octob er 2015. Retr iev ed M ay 2016 fr om http://www.h ealth.gov.on .ca/en/p ro/pro grams/immunizatio n/do cs/im muniz ation _sch edule.p df 6 Deeks et al. Pro long ed p ertussis o utbreak in Ont ario orig inating in an und er-im muniz ed religio us co mmun it y. Can ad a Co mmunicable Disease R eport, 40(3), 2014. 7 Public Health N otice Upd ate - Outb reak of C yclospo ra und er invest igatio n. Public H ealth Ag en cy of C anad a. Retr ieved May 2016 fro m http://www.ph ac- aspc.gc.ca/phn- asp/2015/cyclo spor a-eng .php 8 9 Monthly Infectiou s D isease Surveillan ce Repo rt, F ebru ar y 2015. Public H ealth Ontar io. Retrieved F ebru ar y 2016 from http://www.p ublich ealthontar io.ca/en /Dat aAnd An alyt ics/Do cu ment s/PHO_Monthly_Infectiou s_D iseases_Surveillance_Rep ort_- _Feb ruar y_2015.pdf Guid elines for Testing and Tr eat ment of Gono rrhea in Ontar io, April 2013. Public H ealth Ontar io. R etrieved Feb ruar y 2016 fr om http://www.pub lichealthont ario .ca/en/eR epo sitor y/Gu idelin es_Gonorrh ea_Ontario _2013.pdf 10 Rabies, 2016. Governm ent of Ontar io. R etrieved Feb ruar y 2016 fr om www.ont ario .ca/p ag e/r abies 11 iPH IS d at a caveats for Quer y. Public H ealth Ontar io. R etrieved Feb ruar y 2016 fr om pu blichealthont ario.ca 12 Qu er y Met adat a (Inf ectious Diseases). Public H ealth Ontar io. Retr ieved F ebru ar y 2016 from publich ealthontar io.ca 13 NHS U ser Guid e, N ation al Household Survey, 2011. Retrieved F ebru ar y 2016 from http://www12.st atcan.g c.ca/nh s-enm /2011/r ef/nhs- enm _guide/99-001- x2011001- eng.pdf 2015 Halton Region Infectious Disease Report 75
