Giving high-risk food to vulnerable people in medical settings should be avoided, according to a review of healthcare-associated foodborne outbreaks that included the United States.

Researchers said diets should be nutritious and tasty without using high-risk foods but they acknowledged limited budgets of healthcare operations may impact the quality of food served.

As the proportion of elderly people is projected to increase, the share of the population as patients in healthcare facilities (HCF) is likely to rise and so is the risk associated with healthcare-associated foodborne outbreaks (HA-FBO).

Researchers searched for HA-FBOs between 2001 and 2018 from 37 Organisation for Economic Cooperation and Development (OECD) countries and from 2012 to 2018 in the German surveillance system as well as looking at 2010 to 2018 data from the European Food Safety Authority (EFSA).

They found 57 HA-FBOs from 16 OECD countries. Eleven each in the United States and Germany and nine in the United Kingdom. Also, 28 outbreaks came from the German surveillance system, based on the study published in the journal Eurosurveillance.

Main pathogens
The top three pathogens associated with the 85 outbreaks were Salmonella, norovirus and Listeria monocytogenes. In total, these infected 3,802 people and caused 90 deaths.

In the EFSA database, 14 countries reported 88 HA-FBOs. The top pathogens were norovirus, Salmonella and Clostridium perfringens. Most were reported by Poland and France.

Of the 85 outbreaks, 24 were caused by Salmonella, 22 by norovirus and 19 by Listeria monocytogenes. One HA-FBO was from the parasite Cyclospora cayetanensis while another was associated with the fungus Blastoschizomyces capitatus. based on number of deaths, Listeria monocytogenes was the main pathogen causing HA-FBOs.

A high number of patients per outbreak was observed in norovirus HA-FBOs with a median of 35 cases and a range of two to 570, with one reported death. Salmonellosis reports included a median of 29 patients per outbreak with a range of two to 130 and 11 deaths.

Listeriosis typically had a smaller number of cases per outbreak with a median of five and range of two to 48 but a higher number of deaths with 65. The four E. coli incidents had a high number of patients per outbreak with a median of 77 and range of four to 109, including eight deaths.

Employees such as medical and non-medical staff and food handlers at healthcare facilities were mentioned among patients in 27 of 61 outbreaks.

Overall, 39 of 85 outbreaks occurred in hospitals, 23 in nursing homes, 13 at multiple healthcare settings and 10 in rehabilitation centers. Listeria was responsible for 16 incidents affecting hospitals, while in nursing homes, nine were caused by Salmonella.

Avoid serving high risk foods
Frequently reported implicated foods were mixed foods, vegetables and fruits and meat and meat products. Mixed foods included seven listeriosis outbreaks associated with sandwiches. Four of six fruit outbreaks were linked to frozen berries contaminated by norovirus. In 10 of 35 outbreaks, food or ingredients considered risky for vulnerable people in health care facilities were mentioned such as deli meat, raw oysters and bean sprouts.

Frozen berries should be heat-treated before consumption or not served to vulnerable or immunocompromised patients. Fresh produce such as mung bean sprouts, raw celery and raw spinach should be considered as risky for vulnerable patients, said researchers.

Consumption of high-risk food by vulnerable patients, inadequate time or temperature control, insufficient kitchen and food hygiene and carriers of pathogens among food handlers were reported as reasons for outbreaks.

In 29 HA-FBOs, traceback investigations linked the incidents to catering companies or suppliers showing strict control of supply chains is needed. In several outbreaks, there were also patients in the community.

Work was part of the NOVA project under the One Health EJP, the European unio’s Horizon 2020 research and innovation program.