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Infectious Gastrointestinal Disease/stomach bugs in the home - it’s not all foodborne! This leaflet has been put together to provide background information on gastrointestinal (infectious intestinal) diseases with particular reference to the home. The target audiences for this briefing material are those in healthcare professions, the media and others who are looking for background understanding of gastrointestinal disease and/or those who are responsible for informing the public about gastrointestinal diseases in the home and their prevention through good hygiene practice. What is infectious gastrointestinal disease? The case definition of infectious gastrointestinal disease (IID) is: people reporting diarrhoea or significant vomiting lasting less than 2 weeks, preceded by a symptomfree period of at least 3 weeks in the absence of a known non-infectious cause. Vomiting is considered significant if it occurs more than once in a 24-hour period, incapacitates the person or is accompanied by other symptoms such as cramps or fever. Gastrointestinal (GI) disease is caused by the consumption of contaminated food and water, or it may be transmitted from person-to-person either directly or indirectly. Examples of indirect transmission are via the hands, environmental surfaces or the airborne route (e.g. inhalation of aerosols from vomit). It is not known what proportion of gastrointestinal infections are spread by food, and what proportion are spread by other routes e.g. person-to-person transmission, but it is likely that this varies significantly from one country to another. In Europe for example, it is estimated that up to 60% of GI disease outbreaks are non foodborne, Foodborne disease in the home is described in the IFH fact sheet on foodborne disease. What are the main causes of infectious gastrointestinal disease? Gastrointestinal infections can result from ingestion of the following species: Bacteria: Campylobacter, Salmonella, Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, Bacillus spp., Shigella spp., Helicobacter pylori, Salmonella typhii, Vibrio cholera. Viruses: norovirus, rotavirus, adenovirus and astrovirus, Amoebae and other protozoa: Giardia spp. and Cryptosporidium. How do stomach bugs get into the home? An infected family member may act as the primary source of infection in the home. Infected people may show no symptoms and may spread infection unknowingly. People can continue to harbour and shed stomach bugs after symptoms have ceased. Through infected food purchased from retail premises. The most common sources are meat and poultry, raw eggs, unpasteurised milk, filter feeding shellfish (e.g. oysters, mussels and clams) which are harvested from sewagecontaminated waters, or vegetables grown or washed in polluted water. Through contaminated water. Domestic animals can carry some types of stomach bugs e.g. Salmonella and Campylobacter, and may shed them in their faeces. How do stomach bugs spread in the home and cause infection? Stomach bugs enter the body to infect the gastrointestinal tract via the mouth. The microbes enter the mouth either on food or on contaminated hands (fingers) touching the mouth. It can also sometimes enter the GI tract through the inhalation of aerosolised vomit. Infected vomit particles may be distributed as an aerosol into the environment during a vomiting attack. The aerosol can settle on surfaces in the home, where the organisms can remain infective on hard surfaces or fabrics for several hours or days. Some organisms e.g. Salmonella and Campylobacter survive for only short periods (1-4 hours) whilst others e.g, norovirus can survive for days or even weeks. Where someone has fluid diarrhoea, flushing the toilet produces an aerosol which can settle on surfaces such as the toilet seat or toilet flush handle. Contaminated food can cause infection: If raw foods such as poultry or shellfish bought from the supermarket are eaten raw or are not properly cooked, they can cause infection. The stomach bug can also be spread to other foods (cross contamination) which the poultry, shellfish or other contaminated food comes into contact with. Infection can be spread from an infected family member to an unaffected family member in a number of ways: From hand to mouth. The hands of an uninfected person can be contaminated shaking hands with an infected person or touching a surface which has been contaminated by aerosol particles or touched by a person with contaminated hands Via Food. This can happen if an infected family member handles or prepares ready-to-eat foods such as sandwiches or salads for other family members By inhalation of infected vomit. There is some evidence to suggest that for some stomach bugs e.g. norovirus infection can occur by inhalation of infected aerosol particles. This may occur if family members are in close proximity to the infected person during, or immediately after, a vomiting attack. Infected animals can cause infection: By hand to mouth or hand to food transfer. This can occur if hands are not washed after handling the animal Page 2/10 Animals can transfer pathogens (e.g. via their paws) to environmental surfaces. The pathogens can then be transferred via hands to the mouth or to ready-to-eat foods. Ready-to-eat foods can become contaminated if placed on a surface (such as a kitchen work surface) that family pets are free to walk across. How common is gastrointestinal disease? In the developed World: Since national surveillance systems mostly focus on foodborne disease, this means that data on GI illnesses relate mainly to foodborne outbreaks in restaurants and hospitals. In the UK, even where “household” outbreaks are reported they mostly involve home catering for parties and other functions and, therefore, are mainly foodborne outbreaks. A 2003 WHO Report stated that, of the total GI disease outbreaks (including foodborne disease) reported in Europe during 1999 and 2000, 60 and 69%, respectively, were due to person-to-person transmission. A study of UK outbreaks suggested that 19% of Salmonella outbreaks and more than half of E. coli O157 outbreaks were transmitted by non-foodborne routes.1 Non-foodborne routes of spread are particularly important for viral infections, which represent the major component of gastrointestinal diseases in many communities. Since milder sporadic cases often go unreported, this means that in many/most countries, the overall GI infection burden, particularly that which is not foodborne, is not known; the most informative data on the overall burden of infection (both foodborne and non-foodborne) in the community comes from community-based studies which have been carried out in some countries: In the UK, an estimate of the true GI infection rates comes from a community- based study of the incidence of GI. This indicates that the true number of sporadic community cases of IID is up to 17 million. Of these, norovirus accounts for 3 million cases and 130,000 GP consultations, and Campylobacter is responsible for 500,000 cases and 80,000 GP consultations.2 The data suggest that up to 1 in 4 people in the UK suffer from a GI illness every year. This community-based study, estimated that only one in 147 cases of gastrointestinal illness is detected by surveillance and that, for every one reported case of Campylobacter, Salmonella, rotavirus and norovirus, another 9.3, 4.7, 43 and 288 cases, respectively, occur in the community. As stated above, according to the UK Food Standards Agency, around half of the annual cases of IID are food poisoning.3 In the US, according to Hall et al, the primary reported mode of transmission in most acute gastroenteritis outbreaks was person to person (52%), followed by foodborne (35%), waterborne (2%),animal contact (1%), and environmental contamination (0.2%). Person-to-person transmission was implicated in most outbreaks caused by norovirus (66%) and Shigella spp. (79%), whereas foodborne transmission was implicated in most outbreaks caused by Salmonella spp. (72%) and STEC (63%). Among the 3,052 reported outbreaks for which a single exposure setting was reported, health care facilities were the most frequent settings (49%), followed by restaurants etc (22%), schools or day-care facilities (10%), and private residences (7%). Private residences and restaurants were the most frequent exposure settings for outbreaks caused by Salmonella spp. (32% and 36%, respectively) and STEC (46% and 20%,respectively).4 Page 3/10 This follows on from an earlier (199) study by Mead et al. The results opf this study are shown in Table 2. Table 2 – Estimated annual infectious gastrointestinal illnesses in the USA (From Mead et al 1999 Norovirus Rotavirus Campylobacter Salmonella Shigella Hepatitis A E. coli O157 Total infectious GI illnesses 23,000, 000 3,900,000 2,453,926 1,412,498 448,240 83,391 73,480 Infectious illnesses (%) which are non-foodborne 13,800,000 (60%) 3,861,000 (99%) 490,785 (20%) 70,624 (5%) 358,952 (80%) 79,221 (95%) 11,022 (15%) In a Netherlands study carried out between 1996 and 1999, it was estimated that about 1 in 3.5 people experience a bout of infectious GI disease each year. Campylobacter was detected most frequently (10% of cases), followed by Giardia lamblia (5%), rotavirus (5%), norovirus (5%) and Salmonella (4%). Relative to the population of The Netherlands (16 million), 650,000 norovirus gastroenteritis cases occur annually.5 A 2007 report in Germany by Krause et al evaluated data from 30,578 outbreak reports captured 2001–2005. Of particular note is the fact that the most common settings among the 10,008 entries for 9,946 outbreaks in 2004 and 2005 were households (53%).6 In Australia, OzFoodNet sites reported 1,640 outbreaks of gastrointestinal illness affecting 30,193 people and resulting in 722 people being hospitalised. There were 89 deaths associated with these outbreaks. The majority of outbreaks (81%, 1,330/1,640) were due to person-to-person spread, 9% (154/1,640) were suspected or confirmed to have been transmitted by contaminated food, 9% (155/1,640) had an unknown mode of transmission and 1 outbreak was due to transmission from animal to person. In New Zealand, during 2011, there were 581 reported outbreaks of gastrointestinal disease, involving 7796 cases. A total of 204 cases required hospitalisation and four cases died.7 Campylobacter spp accounted for 29 (5%) of outbreaks. The most commonly identified enteric pathogen was norovirus in 31.2% of outbreaks, followed by Giardia spp. in 12.4%, Campylobacter spp. and Cryptosporidium spp. both 5.0% of outbreaks. The most common settings for exposure or transmission were the private home environment (24.8%). Person-toperson transmission was reported for 78.0% of outbreaks in 2011. Foodborne and environmental transmission were reported for 21.0% and 17.7% of outbreaks, respectively. Multiple modes of transmission were implicated in 33.0% of outbreaks. Contamination of food was the most common factor contributing to foodborne outbreaks (40.2%), followed by time/temperature abuse (38.5%,). For New Zealand, over the last 10 years, there have been substantial changes in the reporting of modes of outbreak transmission. Over this period, person-to-person transmission emerged as the most frequently reported mode, a change from foodborne Page 4/10 transmission which was often the most reported mode between 2001 and 2006. The proportion of foodborne outbreaks reported in 2011 (21.0%, 122/581) is similar to what was reported from 2007 to 2010, but less than from 2001 to 2006 (range 28.3% to 52.9%). Between 2001 and 2011, the number of outbreaks with person-to-person transmission reported increased more than three-fold (from 132 to 453, respectively). In 2011 the number of outbreaks with person-to-person transmission was more than three times higher than any other mode of transmission. Environmental transmission is emerging as a more frequently reported mode of outbreak transmission rising from 6.2% of outbreaks in 2001 to 20.3% in 2010 and 17.7% in 2011, respectively. Indications are that norovirus is now the most significant cause of infectious GI illness in the developed world, both outbreak-related and endemic (See IFH fact sheet on norovirus). Rotavirus is the leading cause of gastroenteritis in children under 5 years of age. (See IFH fact sheet on rotavirus). In developing countries: A 2008 report prepared by the WHO estimates that, globally, improving water, sanitation and hygiene has the potential to prevent at least 9.1% of the global disease burden (in disability-adjusted life years or DALYs, a weighted measure of deaths and disability), or 6.3% of all deaths. Children, particularly those in developing countries, suffer a disproportionate share of this burden, as the fraction of total deaths or DALYs attributable to unsafe water, inadequate sanitation or insufficient hygiene is more than 20% in children up to 14 years of age. Although a substantial proportion of this estimated reduction is made up, not only of diarrhoeal disease reduction but also conditions such as malaria, lymphatic filiarisis and schistosomiasis, the report estimates that for diarrhoeal diseases, improvements in water quality (achievable by promotion of home water treatment and safe storage as well as better control of public supply) and the promotion of other hygiene interventions in the home and community could produce, respectively, a 31% and 37% reduction in diarrhoeal disease burden. In developing areas, it is often difficult to establish whether a GI disease outbreak is waterborne or foodborne, or involves direct faecal/oral transfer via hands and surfaces. Most disease that is spread by water is also spread through faecal contamination or person-to-person contact or in contaminated food. Relatively few countries in the developing world have surveillance programmes on GI disease, which means that there is no systematic data on the incidence of these diseases. By contrast all Central/South American and Caribbean countries have some form of notification system. The situation is improving and it is hoped that by 2020 a surveillance network will cover most countries. The 2004 World Health report contains country-by-country statistics on the incidence of some specific infectious diseases, using data for 2002. Data on GI infections associated with E. coli O157 and O104, Shigella, Salmonella, Campylobacter, norovirus and rotavirus are reviewed in separate IFH fact sheets. Preventing the spread of gastrointestinal infection in the home In situations where there is risk of spread of gastrointestinal infection in the home the following hygiene measures should be rigorously implemented. It must be remembered that stomach bugs can also be spread by people who have no symptoms – both those who have apparently recovered and those who haven’t developed symptoms. The following hygiene measures also apply to preventing the spread of infection in the workplace and schools. Page 5/10 Since the risk of introducing stomach bugs into the home, either via people or foods is constant and may not be recognised until an outbreak of infection occurs within the family, this means that good day-to-day hygiene including good food hygiene makes sense. General Hygiene To prevent transmission of infection from an infected family member (or a family member who may have been exposed to infection outside the home) to other family members or to food: Good handwashing practice is the single most important infection control measure. Hands should be thoroughly washed with soap and running water*. If access to soap and running water is a problem, use an alcohol hand rub or hand sanitiser. Where there is an outbreak in the home, it is suggested that handwashing followed by use of an alcohol rub/sanitiser should be encouraged. Hygienically clean surfaces in the bathroom and toilet, with particular attention to washbasins, baths, toilet seats, toilet handles and showers. This can be achieved by cleaning with a detergent cleaner followed by thorough rinsing under running water, or where this is not possible, e.g. for toilet seats, toilet flush handles etc., using an effective disinfectant cleaner**. If someone has diarrhoea, toilets should be disinfected after each time they use it. Keep the infected person’s immediate environment hygienically clean. The most important surfaces are those which come into contact with the hands, e.g. door handles, telephones, bedside tables, bed frames, computer keyboards, TV remote controls. To make these surfaces hygienically clean use an effective disinfectant cleaner or disinfectant product**, although, for items such as computer keyboards which might be damaged, it is better to make sure the family always wash their hands before using shared family computers. In a busy household it is not always possible to keep hand contact surfaces hygienically clean at all times. This is why it is so important to wash hands as frequently as possible to break the chain of infection. Cleaning cloths can easily spread stomach bugs around the home. They should be hygienically cleaned after each use, particularly after use in the immediate area of the infected person or the bathroom and toilet used by that person. This can be done in any of the following ways: - wash in a washing machine at 60C (hot wash). - clean with detergent and warm water, rinse and then immerse in disinfectant solution for at least 20 minutes or as prescribed. - clean with detergent and water then immerse in boiling water for 20 minutes. Alternatively use disposable cloths. Where floors or other surfaces become contaminated with faeces or vomit, they should be hygienically cleaned at once: - Remove as much as possible of the excreta, from the surface using paper or a disposable cloth, then - Apply disinfectant cleaner** to the surface using a fresh cloth or paper towel to remove residual dirt – then - Apply disinfectant cleaner** to the surface a second time using a fresh cloth or paper towel to destroy any residual contamination. Disposable gloves should be worn if in contact with faeces, and hands should be washed after removing gloves. Page 6/10 After someone has vomited, if possible, vacate the room and ventilate the room by opening windows for a short time to disperse aerosol particles Clothing, sheets and pillows and linens from the infected person (or carrier) should be kept separate from the rest of the family laundry and should be laundered in a manner which kills any stomach bugs. Either: - for preference, wash at 60C or above, using a powder or tablet detergent containing active oxygen bleach (see ingredients on back of pack). - alternatively wash at 40C with a powder or tablet detergent containing active oxygen bleach (see ingredients on back of pack) Note: washing at 40C without the presence of bleach will not destroy stomach bugs Do not share towels, facecloths, toothbrushes and other personal hygiene items with the infected or carrier person. Where young children are ill, or at particular risk: - their handwashing, personal and toilet hygiene may need supervision - nappies should be disposed of safely, or cleaned, disinfected and washed. Contrary to popular perception, the faeces of babies can be highly infectious. Where possible, infected people should stay in their own room and use their own facilities, cutlery, crockery etc. Infected people should particularly avoid contact with those who may be more vulnerable to infection, and their personal items. Food and Kitchen hygiene Rigorous food hygiene is important in preventing the spread of stomach bugs in the home. Where there is an infected person in the home, food hygiene practices should focus on preventing contamination of food, particularly ready-to-eat foods such as sandwiches and salads. Where there is a suspected food source of the outbreak in the home, food hygiene practice should focus on containing and destroying the source, and preventing transfer to other foods. Infected people should try to stay away from the kitchen and should not prepare food for others. Wash hands after handling food which may be contaminated and disinfect using an alcohol handrub or sanitiser. Wash hands before handling ready-to-eat foods and disinfect using an alcohol handrub or sanitiser. Hygienically clean all food contact surfaces, utensils and cloths after handling and preparation of raw foods using a disinfectant cleaner**. Hygienically clean all contact surfaces, utensils and cloths before handling and/or preparing ready-toeat foods. Cook foods thoroughly. Wash any foods such as fruit and vegetables to be eaten raw thoroughly under clean running water. Store foods carefully in a refrigerator or freezer. Ensure that cooked foods are kept separate from uncooked foods. *How to wash hands Handwashing “technique” is very important. Rubbing with soap and water lifts the germs off the hands, but rinsing under running water is also vital, because it is this process which actually removes the germs from the hands. The accepted procedure for handwashing is: Page 7/10 ensure a supply of liquid soap, warm running water, clean hand towel/disposable paper towels and a foot-operated pedal bin always wash hands under warm running water apply soap rub hands together for 15–30 seconds, paying particular attention to fingertips, thumbs and between the fingers rinse well and dry thoroughly. In situations where soap and running water is not available an alcohol- based hand rub or hand sanitiser should be used to achieve hand hygiene: apply product to the palm of one hand rub hands together rub the product over all surfaces of hands and fingers until your hands are dry. Note: the volume needed to reduce the number of germs on hands varies by product. In high risk situations where there is an outbreak in the home, handwashing followed use of an alcohol rub/sanitiser should be encouraged. One very simple thing which people can do which can significantly reduce the risk of disease is to avoid putting their fingers to their mouth. **Disinfectants and disinfectant cleaners: Make sure you use a disinfectant or disinfectant/cleaner such as a bleach-based product, which is active against the type of stomach bug which is causing the outbreak. In many situations it is likely that the causative organisms will not be known. In this case it is important to use a disinfectant or disinfectant cleaner which is active against all types of organisms (bacteria and viruses). For more details on choosing the appropriate disinfectant, consult the IFH information sheet “Cleaning and disinfection: Chemical Disinfectants Explained”. Also consult the manufacturers’ instructions for information on the “spectrum of action”, and method of use (dilution, contact time etc). For bleach (hypochlorite) products, use a solution of bleach, diluted to 0.5% w/v or 5000ppm available chlorine. Household bleach (both thick and thin bleach) for domestic use typically contains 4.5 to 5.0% w/v (45,000-50,000 ppm) available chlorine. In situations where “concentrated bleach” is recommended a solution containing not less than 4.5% w/v available chlorine should be used. Bleach/cleaner formulations (e.g. sprays) are formulated to be used “neat” (i.e. without dilution). It is always advisable however to check the label as concentrations and directions for use can vary from one formulation to another. Good Food hygiene practice in the home is described in more detail in: 1. Home Hygiene - prevention of infection at home: a training resource for carers and their trainers. International Scientific Forum on Home Hygiene. Available from: http://www.ifh-homehygiene.org/2003/2public/2pub06.asp. 2. Home Hygiene in Developing Countries: Prevention of Infection in the Home and Peridomestic Setting. A training resource for teachers and community health professionals in developing countries. International Scientific Forum on Home Hygiene. Available from: http://www.ifh-homehygiene.org/2003/2PUBLIC/ifh_ training_resource.pdf. Page 8/10 Other “facts about” sheets giving information on infectious gastrointestinal disease 1. 2. 3. 4. Foodborne disease and home hygiene. International Scientific Forum on Home Hygiene. http://www.ifh-homehygiene.org/factsheet/foodborne-disease-andhome-hygiene UK Health Protection Agency – Infectious Diseases http://www.hpa.org.uk/ webw/HPAweb&Page&HPAwebContentAreaLanding/Page/1153386734379?p= 1153386734379. US Centre for Disease Control and Prevention. http://www.cdc.gov/Diseases Conditions/. European Centre for Disease Control and Prevention. http://www.ecdc.europa.eu/en/healthtopics/Pages/AZIndex.aspx IFH Home Hygiene Guidelines and Training Resources Guidelines for prevention of infection and cross infection the domestic environment. International Scientific Forum on Home Hygiene. Available from: http://www.ifh-homehygiene.com/best-practice-care-guideline/guidelinesprevention-infection-and-cross-infection-domestic Guidelines for prevention of infection and cross infection the domestic environment: focus on issues in developing countries. International Scientific Forum on Home Hygiene. Available from: http://www.ifh-homehygiene.org/bestpractice-care-guideline/guidelines-prevention-infection-and-cross-infectiondomestic-0 Recommendations for suitable procedure for use in the domestic environment (2001). International Scientific Forum on Home Hygiene. http://www.ifhhomehygiene.org/best-practice-care-guideline/recommendations-suitableprocedure-use-domestic-environment-2001 Home hygiene - prevention of infection at home: a training resource for carers and their trainers. (2003) International Scientific Forum on Home Hygiene. Available from: http://www.ifh-homehygiene.com/best-practice-training/home-hygiene%E2%80%93-prevention-infection-home-training-resource-carers-and-their Home Hygiene in Developing Countries: Prevention of Infection in the Home and Peridomestic Setting. A training resource for teachers and community health professionals in developing countries. International Scientific Forum on Home Hygiene. Available from: www.ifh-homehygiene.org/best-practice-training/homehygiene-developing-countries-prevention-infection-home-and-peri-domestic. (Also available in Russian, Urdu and Bengali) This fact/advice sheet was last updated in 2015 Further Information The changing hygiene climate: a review of infectious disease in the home and community. International Scientific Forum on Home Hygiene. www.ifh-home hygiene.org – 2008. Bloomfield SF, Exner M, Fara GM, Nath KJ, Scott, EA; Van der Voorden C. The global burden of hygiene-related diseases in relation to the home and community. (2009) International Scientific Forum on Home Hygiene. Page 9/10 http://www.ifh-homehygiene.org/review/global-burden-hygiene-related-diseasesrelation-home-and-community The Community Summary Report on Trends and Sources of Zoonoses, Zoonotic Agents, Antimicrobial resistance and Foodborne outbreaks in the European Union. http://www.efsa.europa.eu/en/zoonosesscdocs/zoonosescomsumrep.htm Centre for Diseases Control and Prevention. Preliminary FoodNet data on the incidence of infection with pathogens transmitted commonly through food – in 10 states, 2006-2013. http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6315a3.htm WHO, Five keys to safer food. 2006. Food Safety Department. World health Organisation.www.who.int/foodsafety/publications/consumer/manual_keys.pdf References 1 2 3 4 5 6 7 WHO. Water and Health in Europe: A Joint Report from the European Environment Agency and the WHO Regional Office for Europe. 2002. Eds: Bartram J, Thyssen N, Gowers A, Pond K, Lack T. The Longitudinal study of infectious intestinal disease in the UK (IID2 study): incidence in the community and presenting to general practice Tam CC, Rodrigues LC, Viviani L, et al. Gut (2011). doi:10.1136/gut.2011.238386. Food Standards Agency. A report of the study of infectious intestinal disease in England (TSO, 2000). Hall AJ, Wikswo ME, Manikonda K, Roberts VA, Yoder JS, Gould LH. Acute gastroenteritis surveillance through the National Outbreak Reporting System, United States. Emerg Infect Dis. 2013. http://dx.doi.org/10.3201/eid1908.130482 . de Wit MA, Koopmans MP, Kortbeek LM, van Leeuwen NJ, Bartelds AI, van Duynhoven YT. Gastroenteritis in sentinel general practices in The Netherlands. Emerging Infectious Diseases 2001;7:82-91. Krause G, Altmann D, Faensen D, et al. SurvNet electronic surveillance system for infectious disease outbreaks, Germany. Emerging Infectious Diseases 2007; 13:1548-55. Summary of Outbreaks in New Zealand 2011. Institute of Environmental Science and Research Limited. July 2012. https://surv.esr.cri.nz/PDF_surveillance/AnnualRpt/AnnualOutbreak/2011/2011Out breakRpt.pdf Page 10/10