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Washing those dirty dishes in public and in private

Sally Bloomfield
BPharm PhD MRPharmS
International Scientific Forum on Home Hygiene (IFH) and Visiting Professor of Environmental Health
Division of Life Sciences
King's College London

Infectious intestinal disease (IID) or gut infections are a huge problem in the UK. It is estimated that 9.4 million cases occur in England and Wales every year.(1) Most people with IID get through it at home without needing any medical attention. But every year around 35,000 people are admitted to hospital because of IID, and up to 300 die from it.(2,3) According to the UK Food Standards Agency (FSA), almost half of IID cases are thought to be food poisoning.(2)
The FSA, the UK food safety watchdog, has acknowledged that food hygiene needs to be improved and is currently running a high-profile campaign aimed at both the general public and the catering industry. The FSA has set itself a target of reducing the incidence of food poisoning by 20% by 2006.
It has been estimated that up to eight out of 10 cases of food poisoning originate in the home.(4) Being made aware of this fact makes people realise that they are in control and can reduce their risk. Food poisoning is not something that they just suffer, but an unpleasant condition that they can prevent. That is why education is so important.

The role of nurses in home hygiene education
Nurses can play an important role in educating patients and their families about home hygiene. Although a nurse often has only limited time with a patient, focusing on a few key messages can be effective and change patient behaviour.
Health education on home hygiene can be carried out opportunistically - for example, if a patient has recently suffered from food poisoning. Otherwise, "at-risk" patients can be targeted easily - the old, the very young, pregnant women, the immunosuppressed and those weakened by chronic illness. Food poisoning is more debilitating for "at-risk" groups, and in some cases is fatal.
The basics of kitchen hygiene can be reinforced with the elderly and their carers. Mothers with young babies and toddlers are often more receptive to improving kitchen behaviour fuelled by concern about the health of their children. Home hygiene is an important subject for pregnant women, to protect both their own health and that of their baby.
When seeing patients who are immunosuppressed or weakened by disease it is relevant to discuss their vulnerability to infection and measures that can reduce their risk. 
Research shows that IID is caused by a variety of pathogens. The main bacteria that cause IID are Salmonella, Campylobacter, Listeria and Escherichia coli. Common viruses include Norwalk-like viruses (NLV) and rotaviruses. One survey found that 38% of all UK IID cases were caused by a virus, and 25% by bacteria.(5) The rest could not be identified, but half were thought to be caused by a virus. Although half of these infections are foodborne, the remainder, particularly the NLV or "winter vomiting virus", are transmitted from one person to another.
It is easy for people to feel overwhelmed by the subject of home hygiene and to worry that the only way to reduce the risk of infection is by becoming obsessively clean. This can often have the effect of turning them off home hygiene altogether. They are far more likely to change their behaviour if they realise that just a few simple changes can make a lot of difference.
Experience is now showing that a rational approach to home hygiene is the best option. This means targeting the sites, surfaces and activities in the toilet, bathroom, kitchen and other areas that carry the greatest risk of cross- contamination - it's not about trying to create a germ-free home. 
As far as foodborne infection is concerned, logically the kitchen is the area of primary concern as it is where food is prepared. By concentrating on the at-risk areas in the kitchen, the risk of food poisoning is radically reduced. Pathogens come into the kitchen in a variety of ways. Many that occur in food come from animals or their products - meat, poultry, eggs and milk, for example. The UK FSA quotes an average contamination rate of 50% for Campylobacter and 6% for Salmonella in chickens; however, regional figures vary, so that, for example, the figure for Salmonella in frozen chickens in Scotland stands at 17.4%, and for Northern Ireland the contamination for Campylobacter in fresh chickens remains at 89%.(6) A recent study from the Public Health Laboratories showed that Salmonella and Campylobacter were present in 25% and 83% of raw chickens, respectively. Both pathogens were isolated from the outside of the packaging in 6% of packaged chickens.(7)
Vegetables can be contaminated from manure, sewage or dirty water. Pathogens can be introduced into the kitchen by humans, who, for example, have not washed their hands properly after going to the toilet.
In the kitchen, it is not just the risk of cross-contamination that is a problem: cooking, reheating and the storage of food all represent high-risk activities. Research has shown that 40% of all food-related outbreaks in the home are caused by inappropriate storage of food, 20% of cases are caused by cross-contamination and 31% by inadequate cooking of food.(8)
By addressing these three facets of kitchen hygiene, the risk of food poisoning will be significantly reduced.
Cross-contamination is one of the major causes of food poisoning. Cross-contamination is the transfer of pathogens from an infected source to another source, such as raw food to other foods. This can happen when one food touches or drips onto another. It can also happen when raw food or an infected person transfers an infection to cooking equipment such as a chopping board, knife or work surface. Cooked and prepared food can then become contaminated with these pathogens through contact. But the risk of cross-contamination can be reduced with just a few simple measures (see Table 1).

[[NIP13_table1_43]]

Appropriate and adequate handwashing is essential to good kitchen hygiene. A Food and Drink Federation survey found that 26% of men and 17% of women do not always wash their hands before preparing food. And 31% of men and 17% of women said they do not regularly wash their hands after using the toilet.(9)
Hands should be washed before starting food preparation and after handling raw foods. Warm water, liquid soap and a thorough technique should be employed, after which the hands should be rinsed in running water and then dried thoroughly on a clean dry towel or kitchen roll, not on an apron!
Thorough cooking removes another major risk in the kitchen as it kills commonly occurring bacteria such as Salmonella and Campylobacter. Again, following simple rules eliminates the risk (see Table 2).

[[NIP13_table2_43]]

Food storage is the other major risk in the kitchen. Storing food at the right temperature will prevent pathogens multiplying beyond safe levels (see Table 3).

[[NIP13_table3_43]]

Nurses have an important role to play in educating the public on simple measures that will reduce their chance of contracting food poisoning in the home. Both targeted and opportunistic health education should contribute to reducing the risk of domestic food ­poisoning.

References

  1. Wheeler JG, Sethi D, Cowden JM, et al. Study of infectious intestinal disease in England; rates in the community, presenting to general practice, and reported to national surveillance. BMJ 1999;318:1946-50.
  2. Djuretic T, Ryan MJ, Wall PG. The cost of inpatient care for acute infectious intestinal disease in England from 1991 to 1994. Commun Dis Rep Rev 1996;6:R78-80.
  3. Office of Population Censuses and Surveys. Mortality statistics for England and Wales by underlying cause [DH2/No. 23]. London: HMSO; 1996.
  4. Schmidt K. Situation of foodborne diseases in Europe, 1992-1996. From Proceedings of the 4th World Congress on Foodborne Infections and Intoxications. 7-12 June 1998. Berlin: Federal Institute for Health Protection of Consumers and Veterinary Medicine; 1998. Vol 1, p. 262-6.
  5. Evans HS, Madden P, Douglas C, et al. General outbreaks of infectious intestinal disease in England and Wales; 1995 and 1996. Commun Dis Public Health 1998;1:165-71.
  6. Food Standards Agency. Salmonella in retail chicken drops to an all time low but the battle with campylobacter continues. London: FSA; 2001. Available from URL: http://www.food.gov.uk/news/ pressreleases/salmonellaschick
  7. Jorgensen F, Bailey R, Williams S, et al. Prevalence and numbers of Salmonella and Campylobacter spp on raw, whole chickens in relation to sampling methods. Int J Food Microbiol 2002;76:151-64.
  8. Gillespie IA, O'Brien SJ, Adak GK. General outbreaks of infectious intestinal diseases linked with private residences in England and Wales, 1992-9. BMJ 2001;323:1097-8.
  9. BBC Newsonline. Dirty hands "poison thousands". 11 June 2001. Available from URL: http://news.bbc.co.uk/hi/english/health/newsid_1378000/1378634.stm