Download Emerging and re-emerging infectious disease. ( 16/03/2017)

Emerging and re-emerging
infectious disease.
( 16/03/2017)
Dr Priyadarsh
Moderator –
Dr Chetana Maliye
Dr Abhay Ambilkar
Infectious Diseases: A World in Transition
AIDS
Avian Influenza
Ebola
Marburg
Cholera
Rift Valley Fever
Typhoid
Tuberculosis
Leptospirosis
Malaria
Chikungunya
Dengue
JE
Antimicrobial resistance
UP
?
DOWN
Guinea worm
Smallpox
Yaws
Poliomyelitis
Measles
Leprosy
Neonatal tetanus
No infectious disease has spread so fast and far as SARS did in 2003
SARS Cases
19 February to 5 July 2003
Total: 8,439 cases, 812 deaths,
30 countries in 7-8 months
Europe:
10 countries (38)
Canada (243)
Russian Fed. (1)
Mongolia (9)
USA (72)
China (5326)
Korea Rep. (3)
SARS: The First Emerging Infectious
Disease Of The 21st Century
Kuwait (1)
India (3)
Colombia (1)
Hong Kong (1755)
Macao (1)
Taiwan (698)
Malaysia (5)
Viet Nam (63)
Singapore (206)
Brazil (3)
Indonesia (2)
Philippines (14)
Thailand (9)
South Africa (1)
(
Australia (5)
New Zealand (1)
Source: www.who.int.csr/sars
 Emerging infectious disease
Newly identified & previously unknown infectious agents
that cause public health problems either locally or
internationally
1991 – Peru .
23 Jan 1991
Cholera re-emerged after
100 years.
More than 300000 cases in
1st year.
In 1992, 358174 cases and
2602 deaths.
In 1994, 127180 cases and
1321 deaths.
 Re-emerging infectious disease
Infectious agents that have been known for some time,
had fallen to such low levels that they were no longer
considered public health problems & are now showing
upward trends in incidence or prevalence worldwide
Factors Contributing To Emergence
AGENT
 Evolution of pathogenic infectious agents
(microbial adaptation & change)
 Development of resistance to drugs
 Resistance of vectors to pesticides
Antimicrobial Drug Resistance
 Causes:
• Wrong prescribing practices
• non-adherence by patients
• Counterfeit drugs
• Use of anti-infective drugs in animals & plants
• Loss of effectiveness:
• Community-acquired (TB, Pneumococcal) &
Hospital-acquired (Enterococcal, Staphylococcal
 Antiviral (HIV), Antiprotozoal (Malaria), Antifungal
Factors Contributing To Emergence
HOST
 Human demographic change (inhabiting new areas)
 Human behavior (sexual & drug use)
 Human susceptibility to infection (Immunosuppression)
 Poverty & social inequality
 Unsafe sexual practices (HIV, Gonorrhea, Syphilis)
 Changes in agricultural & food production patterns- foodborne infectious agents (E. coli)
 Increased international travel (Influenza)
 Outdoor activity
Factors Contributing To Emergence
ENVIRONMENT and CLIMATE
 Climate & changing ecosystems
 Economic development & Land use (urbanization, deforestation)
 Technology & industry (food processing & handling)
 International travel & commerce
 Breakdown of public health measure (war, unrest, overcrowding)
 Deterioration in surveillance systems (lack of political will)
 Deforestation forces animals into closer human contact- increased
possibility for agents to breach species barrier between animals & humans
 El Nino- Triggers natural disasters & related outbreaks of infectious diseases
(Malaria, Cholera)
 Global warming- spread of Malaria, Dengue, Leishmaniosis, Filariasis
Transmission of Infectious Agent from
Animals to Humans
 >2/3rd emerging infections originate from animals- wild &
domestic
 Emerging Influenza infections in Humans associated with
Geese, Chickens & Pigs
 Animal displacement in search of food after
deforestation/ climate change (Lassa fever)
 Humans themselves penetrate/ modify unpopulated
regions- come closer to animal reservoirs/ vectors
(Yellow fever, Malaria)
Poverty, Neglect & Weakening of
Health Infrastructure
 Poor populations- major reservoir & source of continued transmission
 Poverty- Malnutrition- Severe infectious disease cycle
 Lack of funding, Poor prioritization of health funds, Misplaced in
curative rather than preventive infrastructure, Failure to develop
adequate health delivery systems
 Growth of densely populated cities- substandard housing, unsafe
water, poor sanitation, overcrowding, indoor air pollution (>10%
preventable ill health)
 Problem of refugees & displaced persons
 Diarrheal & Intestinal parasitic diseases, ARI
Lyme disease (B. burgdorferi)- Changes in ecology, increasing deer
populations, suburban migration of population
Factors influencing emergence and reemergence
 Weakened public health infrastructure
 Failure of safety procedures/regulations.
 Population increase.
 Anthropogenic activities or natural variance in climate
 Civil disturbance/Human displacement
 Human Behaviour –
 - Occupation
 - Mistrust and Misinformation
 - Anti-infective drug prescription and use
 - Deliberate use to cause terror and harm.
Weakened public health infrastructure
 Weakened investment in public health in 2 nd half of twentieth
century and deterioration of mosquito control campaigns led to
resurgence of Aedes aegypti in urban areas.
 Dengue , before 1970 only 11 countries of Latin America had
outbreak , now its in more than 69 countries.
 Now dengue is endemic in more than 100 countries.
 During 2003 , 1.4 million cases and 6600 deaths.
 Chikungunya outbreak in 2005 with initial 3111 human infection
spread across pacific and till March 2006, more than 204000 cases
were reported.
 Lapses in vaccination for diphtheria in USSR around 1990 led to
outbreaks with more than 5000 cases in 1993.
Failure of safety Procedures/
Regulations
 1980 – USSR , Romania – HIV and Hep B in more than 250
children and health workers.
 1976, 1995 – Ebola in democratic republic of Congo
where syringes and failed barrier nursing caused the
diseases in health workers.
 Lapses in universal precautions led to nosocomial
transmission of SARS in China , Hong Kong, Singapore .
The outbreaks then spread through the health workers to
the community.
Population Increase
 During to fast population growth , the sanitation ad basic
infrastructure systems had collapsed or are inadequate.
 Cholera, which was rarely seen in Latin America for more than 100
years , returned back with an outbreak in Peru in 1991.
 It spread rapidly in Latin America.
 It caused nearly 400000 cases and 4000 deaths.
 By 1995, more than 1 million cases and more than 10000 deaths
were reported all over south America.
 Urbanisation has brought its own set of problems.
 In 1994, India witnessed outbreaks of both bubonic and pneumonic
plague in 5 states with around 800 infections and 56 deaths.
Anthropogenic activities or Natural
Variance in climate.
 Deforestation leads to change in habitat of many animals and they start
living closely to human population.
 Lassa fever in west Africa and sine nom virus in North America were
spread in a same way.
 Chagas disease re-emerged due to mis-management of deforested
lands & by movement of triatomines nearer to the human settlements.
 Nisseria meningitides , which is traditionally occurs in sub Saharan Africa
spread . After a drought , it spreaded to Uganda and Tanzania.
 1998 jpnese encephalitis , spread in png due to a drought , increase
breeding sites for culex mostiques in dried river beds.
 It then transmitted through mosquito from birds, pigs, etc. in the area of
Malaysia to India.
 El Nino – Rift valley fever in Kenya, Somalia, Tanzania. 89000 total
infection with 478 deaths
Civil Disturbance/ Human
displacement
 1994 Rwanda – civil disobedience – 48000 cases of
cholera and 23800 death within 1 month of
displacement.
 2004 – Marburg haemorrhagic fever in Angola which
was still going through a civil war, spreading to more
than 200 people and killing more than 90 % cases.
 1998 – Similar outbreak of Malburg virus in Congo.
Human Behaviour
 Occupation
 - Anthrax – wool-sorters disease
 Ebola with people coming in contact with animals.. ( wood
cutters, researchers, zoo workers)
 H7N7 – investigator, poultry workers.
 Mistrust and Misinformation
 -Rumours in 2003 in Nigeria – OPV for infertility. So in 2004 , polio
outbreak. Nigeria had 70 % polio cases among world wide that
year.
Anti infective drug prescription and use
 Over prescribing or under prescribing
 E coli multiple resistant strain are present in each country but
more resistant strains in China and Venezuela , where over
the counter anti biotics are very easily available.
 MDR TB, XDR TB in HIV positive people.
 Use of injudious antibiotics in veterinary cases.
 Deliberate use for bio-terrorism
 Anthrax letter following 9/11.
 Anthrax spores infection through letter to 22 people, 5 of
whom died.
ENVIRONMENT
Climate change
Mega-cities
Vector
proliferation
Migration
Pollution
Exploitation
Antibiotics
HUMAN
Food
production
ANIMALS
Intensive farming
Transmission
Population
Growth
Vector
resistance
VECTORS
Examples of recent emerging diseases
Source: NATURE; Vol 430; July 2004;
www.nature.com/nature
Emerging Zoonoses: Human-animal
interface
Avian influenza
virus
Borrelia burgdorferi:
Lyme
Bats: Nipah
virus
Deer tick (Ixodes
scapularis)
Ebola virus
Marburg virus
Mostomys rodent: Hantavirus
Lassa fever
Pulmonary Syndrome
Lesson learnt from SARS
 An infectious disease in one country is a threat to all
 Important role of air travel in international spread
 Tremendous negative economic impact on trade, travel
and tourism, estimated loss of $ 30 to $150 billion
 High level commitment is crucial for rapid containment
 WHO can play a critical role in catalyzing international
cooperation and support
 Global partnerships & rapid sharing of data/information
enhances preparedness and response
Swine Flu Influenza A (H1N1)
March 18 2009 – ILI outbreak reported in Mexico
 April 15th CDC identifies H1N1 (swine flu)
 April 25th WHO declares public health emergency
 April 27th Pandemic alert raised to phase 4
 April 29th Pandemic alert raised to phase 5
 By May 5th more than 1000 cases confirmed in 21 countries
 Screening at airports for flu like symptoms (especially passengers coming
from affected area)
 Schools closed in many states in USA
 May 16th India reports first confirmed case
 Stockpiling of antiviral drugs and preparations to make a new effective
vaccine
Pandemic H1N1.
WorldwideCases - 162,380
Deaths -1154
IndiaCases - 558
Death - 1
26
Examples of Re-Emerging Infectious
Diseases
 Diphtheria- Early 1990s epidemic in Eastern
Europe(1980- 1% cases; 1994- 90% cases)
 Cholera- 100% increase worldwide in 1998 (new strain
eltor, 0139)
 Human Plague- India (1994) after 15-30 years absence.
Dengue/ DHF- Over past 40 years, 20-fold increase to
nearly 0.5 million (between 1990-98)
Bioterrorism
 Possible deliberate release of infectious agents by dissident
individuals or terrorist groups
 Biological agents are attractive instruments of terror- easy to
produce, mass casualties, difficult to detect, widespread
panic & civil disruption
 Highest potential- B. anthracis, C. botulinum toxin, F. tularensis,
Y. pestis, Variola virus, Viral haemorrhagic fever viruses
 Likeliest route- aerosol dissemination
National surveillance:
current situation
 Independent vertical control programmes
 Surveillance gaps for important diseases
 Limited capacity in field epidemiology, laboratory diagnostic
testing, rapid field investigations
 Inappropriate case definitions
 Delays in reporting, poor analysis of data and information at all
levels
 No feedback to periphery
 Insufficient preparedness to control epidemics
 No evaluation
IHR and PHEIC
 1969 – Member states of WHO agreed to new set of regulations – The
International Health Regulations.
 For better regulations during trade and travel with minimum
interference for public health security.
 Reporting 4 diseases – Cholera, plague, yellow fever, smallpox.
 Pre-established control measures at inter national borders.
 2005 – IHR provided a more up-to-date legal framework of reporting
any Public Health Emergency of International Concern.
 Using real time evidence to recommend measures to stop the
international spread of diseases.
 Decision tree instrument is used to classify diseases under PHEIC or not.
 If the disease falls under PHEIC, its notification is needed even for
single case.
GOARN- Global Outbreak Alert & Response
Network
 Coordinated by WHO
 Mechanism for combating international disease outbreaks
 Ensure rapid deployment of technical assistance, contribute to long-term epidemic
preparedness & capacity building
 Multidisciplinary network of technical and operational resources from over 200
global, regional and national public health institutions, specialist public health
networks in epidemiology, infection control and biomedical sciences, networks of
laboratories, many United Nations organizations and international nongovernmental
organizations.
 GOARN harnesses international resources at the request of affected WHO Member
States to augment their response to ongoing or potential public health
emergencies.
 Since its inception GOARN has responded to over 120 deployments in 85 countries
deploying more than 2300 experts in the field to assist Member States characterise
and control disease outbreaks and respond to natural disasters and humanitarian
emergencies
Sharing Outbreak-related Information
• with Public Health Professionals
• with Public
Key Tasks in Dealing with Emerging
Diseases
Surveillance at national, regional, global level
epidemiological,
laboratory
ecological
anthropological
Investigation and early control measures
Implement prevention measures
behavioural, political, environmental
Monitoring, evaluation
Solutions
 Internet-based information technologies
Improve disease reporting
Facilitate emergency communications &
Dissemination of information
 Human Genome Project
Role of human genetics in disease susceptibility, progression & host
response
 Microbial genetics
Methods for disease detection, control & prevention
 Improved diagnostic techniques & new vaccines
 Geographic Imaging Systems
Monitor environmental changes that influence disease emergence
& transmission
What skills are needed?
Infectious
diseases
Epidemiology
Public
Health
Telecom. &
Informatics
International
field
experience
Laboratory
Information
management
Multiple expertise needed !
Strategy
Public health surveillance & response systems
 Rapidly detect unusual, unexpected, unexplained
disease patterns
 Track & exchange information in real time
 Response effort that can quickly become global
 Contain transmission swiftly & decisively
Key tasks - carried out by whom?
Global
Regional
Synergy
National
Global Disease Intelligence:
A world on the alert
Collection
Verification
Distribution
Response
The Best Defense (Multi-factorial)
 Coordinated, well-prepared, well-equipped PH systems
 Partnerships- clinicians, laboratories & PH agencies
 Improved methods for detection & surveillance
 Effective preventive & therapeutic technologies
 Strengthened response capacity
 Political commitment & adequate resources to address
underlying socio-economic factors
 International collaboration & communication
Thank You
References
 Dikid, T., Jain, S. K., Sharma, A., Kumar, A., & Narain, J. P. (2013). Emerging & reemerging infections in India : An overview, (July), 19–31.
 Morens, D. M., Folkers, G. K., & Fauci, A. S. (2004). The challenge of emerging and reemerging infectious diseases, 430(July).
 Morens, D. M., & Fauci, A. S. (2013). Emerging Infectious Diseases : Threats to Human
Health and Global Stability, 9(7), 7–10. https://doi.org/10.1371/journal.ppat.1003467
 Article, R. (2013). Emerging and re-emerging infections, 7(Suppl 1), 51–56.
 Quaglio, G., Demotes-mainard, J., & Loddenkemper, R. (2012). Emerging and reemerging infectious diseases: a continuous challenge for Europe, 40(6), 1312–1314.
https://doi.org/10.1183/09031936.00111712
 Heymann, D. L. (1992). Emerging and re-emerging infections. Oxford textbook of
public health.
 Emerging and re-emerging infections . Park textbook for preventive and social
medicine.
 Delgado, G., Morales, R., Mendez, J. L., & Cravioto, A. (2011). The Re-emergence of
Cholera in the Americas, 79–95. https://doi.org/10.1007/978-1-60327-265-0