Hospital sandwiches and other ready-to-eat foods pose a high-risk from foodborne listeria contamination in vulnerable groups, particularly among the elderly and immunocompromised.
According to the Health Protection Agency (HPA), sandwiches sales from contracted suppliers across the NHS are valued at approximately £13M a year, which equates to roughly 16M sandwiches. If those from other sources, including ones made in-house, are added, the total is likely to be even higher.
At a recent meeting of the Food Standards Agency’s (FSA’s) Advisory Committee on the Microbiological Safety of Food (ACMSF), experts expressed considerable concern about this source of food poisoning. It comes at a time when there is a rising incidence of the disease listeriosis across Europe, which epidemiologists are at a loss to explain. They suspect it is to do with eating pattern changes in the food chain and greater consumption of products more at risk.
The HPA said that in the first five months of 2007 there had been a continued increase in the numbers of human listeriosis cases reported in the UK, compared with the 1990s. For the first 22 weeks of the year there had been 87 cases reported, resulting in 25 deaths of which 20 were in patients over 60 years of age.
The disease, although rare, is severe for vulnerable groups and can result in miscarriages among pregnant women, septicaemia or central nervous systems infections. High mortality rates are reported in all patient groups, according to HPA infection researcher Jim McLaughlin.
McLaughlin cited an incidence of listeria contamination earlier this year from a company supplying a large proportion of its sandwiches to hospitals. In a paper to ACMSF he noted: “This incident, together with previous incidents, highlights the problems with serving this type of food to vulnerable groups in hospitals as ‘‘Listeria monocytogenes’’ may legally be present in ready-to-eat foods up to 100 colony forming units (cfu) per gramme.”
He added: “I feel uncomfortable about some of the lower levels - especially in food given to vulnerable groups such as in hospital.”
A similar contamination problem had occurred in the same factory in 2005, he said. And, highlighting the potential risk, he added that early in 2006, the factory had been supplying 10,000 sandwiches a day to outlets in the south east of England, of which 40% were hospitals.
Previous surveys have shown that butter and sandwiches from hospitals and residential/care homes had detected the presence of ‘‘Listeria monocytogenes’’, the levels were within legal limits. In contrast, higher numbers of vacuum-packed and modified atmosphere cooked meals at the end of shelf-life were detected with levels exceeding 100cfu. Common risk factors for contamination are storage at temperatures above 8°C and the absence of hazard analysis critical control point procedures, reported McLaughlin.