Food poisoning is not often associated with hospital, but last year’s incident in Manchester has highlighted that people in hospitals may be affected: six people died as a result of an outbreak of Listeria last summer.

Listeriosis is rare and usually does not affect healthy people. However, hospital patients are at higher risk due to their pre-existing conditions and compromised immune systems. Listeria is associated with raw foods such as unpasteurised milk, cheeses and uncooked meats, although contamination of raw vegetables is also common. These bacteria can survive nearly freezing temperatures, therefore appropriate refrigeration and handling does little to prevent the illness.

While it was most likely out of the hospital’s control to prevent the outbreak in Manchester, many may ask whether healthcare professionals know enough about foodborne disease to protect their patients.

Food safety in hospitals should be a priority because their population is at higher risk of developing foodborne diseases. Evidence demonstrates that nosocomial foodborne outbreaks are associated with higher mortality risk than that observed in community outbreaks.¹ Chemotherapy and transplant patients are most vulnerable and are often put on special diets which exclude raw fruit and vegetables and other foods associated with high risk of infection. By law, all hospitals and other healthcare settings must follow the Hazard Analysis and Critical Control Points (HACCP) standards to manage food safety in their institutions. To comply with this law, all food handlers and their supervisors must adhere to the food safety standards set by their institution.

As a result of these precautions, food poisoning outbreaks in hospitals are rare. Some outbreaks – the Listeria outbreak mentioned above is a good example – are associated with HACCP standards not being observed by external suppliers. In these cases, contaminated, often pre-cooked or pre-prepared products enter hospital premises. An outbreak of Clostridium perfringens occurred in a UK hospital where 44 patients who consumed pre-cooked roast pork became ill.² In some cases, for example a Salmonella enteritidis outbreak involving 22 immunocompromised patients in Spain, poor kitchen hygiene practices were implicated as a source of food contamination.³

However, following HACCP principles does not guarantee that food is free of contaminants: it is a quality control measure that helps to identify potential hazard points and prompts an introduction of further control measures to minimise those hazards. Previous outbreaks in hospitals have frequently been associated with asymptomatic staff, in which cases following HACCP would not be sufficient to prevent the disease. One such outbreak took place in a UK hospital in the 1990s. 12.3% of catering staff were found to be asymptomatic carriers of Salmonella enteritidis who intermittently contaminated patient meals due to poor personal hygiene.⁴ A similar outbreak was reported in a private London hospital where an asymptomatic food handler contaminated a batch of sandwiches. Interestingly, the food handler became ill a few days following the outbreak, and it was reported that their baby showed symptoms of infection a few days before the hospital case was identified.⁵ Clearly, poor understanding of the importance of personal hygiene and infection control played a significant role in both outbreaks.

One study conducted in Italy investigated the knowledge of food-service staff. Researchers found that not all staff were aware of foodborne pathogens, and that some did not have sufficient knowledge of safe temperatures for food storage.⁶ The same study asserted that despite the knowledge staff did have, not all staff used safe practices when handling food. These findings may explain the results of another study which reported a high incidence of bacterial contamination of food-contact surfaces in hospitals, with pathogens such as S. aureus, E. coli and Serratia marcescens being widely present.⁷ Furthermore, another study of catering staff conducted in Japan demonstrated that a low level of job satisfaction due to organisational issues resulted in low job-commitment and inadequate compliance with organisational standards, subsequently leading to a serious food poisoning incident.⁸

Healthcare staff also seem to have poor knowledge of foodborne disease. One study reported that despite being frequently involved in food service, nurses had a general lack of understanding about the aetiology of  foodborne diseases and the mechanisms for spread.¹ The nurses were reported to use protective clothing and gloves, but did not demonstrate adequate skills for food handling. Moreover, the majority of the nurses (80%) also reported that they did not attend any food hygiene-related training. Similarly, a survey among healthcare professionals showed that only 21% of the respondents correctly answered at least 60% of the foodborne disease-related questions.⁹

Nosocomial foodborne disease is rare, but potentially detrimental to the health of hospital patients. Outbreaks are usually associated with contaminated food supplied by external sources, but there is also evidence that catering staff as well as healthcare professionals do not have sufficient understanding of this problem. Nutrition and Hydration Week 2020 provides a great opportunity for us to raise awareness and learn more about these potentially fatal illnesses.

Read more about Nutrition and Hydration Week 2020 here: https://nutritionandhydrationweek.co.uk/ 

1. Buccheri, C., Casuccio, A., Giammanco, S. et al. Food safety in hospital: knowledge, attitudes and practices of nursing staff of two hospitals in Sicily, Italy. BMC Health Serv Res. 2007; 7: 45.

2. Regan, C.M., Syedt, Q., Tunstall PJ. A hospital outbreak of Clostridium perfringens food poisoning – implications for food hygiene review in hospitals. J Hosp Infect. 1995;29:69–7

3. Dryden, M.S., Keyworth, N., Gabb, R. et al. Asymptomatic food handlers as the source of nosocomial salmonellosis. J Hosp Infect. 1994 Nov;28(3):195-208.

4. Guallar, C., Ariza, J., Dominguez, M.A., et al. An insidious nosocomial outbreak due to Salmonella enteritidis. Infect Control Hosp Epidemiol. 2004;25:10–15.

5. Maguire, H., Pharoah, P., Walsh, B. et al. Hospital outbreak of Salmonella virchow possibly associated with a food handler. J Hosp Infect. 2000 Apr;44(4):261-6.

6. Angelillo, I.F., Viggiani, N.M., Greco, R.M. et al. HACCP and food hygiene in hospitals: knowledge, attitudes, and practices of food-services staff in Calabria, Italy. Collaborative Group. Infect Control Hosp Epidemiol. 2001 Jun;22(6):363-9.

7. Touimi, G.B., Bennani, L., Berrada, S., et al. Evaluation of hygienic conditions of food contact surfaces in a hospital kitchen in Morocco. Iran J Microbiol. 2019 Dec;11(6):527-534.

8. Kubota, S., Kawai, H. Comprehensive study on the prevention of food poisoning through the investigation of an affected hospital food service facility. Nihon Eiseigaku Zasshi. 2015;70(1):69-80.

9. Efunshile, M.A., Onwakpu, K.O., Robertson, L.J. et al. Opinions and knowledge on globally important foodborne parasites among healthcare professionals at a tertiary teaching hospital in Nigeria. Food Waterborne Parasitol. 2020 Feb 21;18:e00075.