Everything you need to know about the hospital food listeria outbreak – New Scientist News

Listeriosis is caused by Listeria monocytogenes bacteria

Two more people are reported to have died after eating contaminated sandwiches at a UK hospital, bringing the total to five fatalities. Here’s everything you need to know about the listeria outbreak.

What happened?

On 7 June, it was announced that six people in the UK – described as already having been “seriously ill” in hospital – had developed listeria infections. Three of them died as a result of the infection. Now two more deaths have been linked to the same outbreak.

Where did the infection come from?

The infections have been traced back to a sandwich and salad production company that supplies food to hospitals, which has ceased production as a result of the outbreak. The company providing meat to the sandwich producer has also halted production, according to Public Health England. UK health minister Matt Hancock has ordered a review of hospital food.

What is listeria and why is it dangerous?

The bacteria can cause an infection called listeriosis, which is rare in the UK. Although it generally causes only mild symptoms, listeriosis can be very dangerous in young babies, elderly people and pregnant women, as well as people with weak immune systems. In vulnerable people, it can spread through the body and attack the brain, or cause miscarriage in pregnant women.

How does the infection spread?

Listeria bacteria can grow in foods, especially soft cheese, unpasteurised milk, and smoked fish, which is why pregnant women are advised to avoid these. It can also grow on other food products, including salads, and can continue to replicate even when food is refrigerated at cold temperatures.

Pre-packed sandwiches have been responsible for some past outbreaks. Three cases were linked to pre-packed sandwiches in Yorkshire and the Humber and the West Midlands in 2017, for example. A recent review of cases in Spain found that cheeses and hams were often likely sources of bacteria, and in the US, deli meats, cheeses and frozen vegetables have been responsible for outbreaks.

Contaminated ready-to-eat meat products were responsible for a huge outbreak in South Africa, which began in 2017 and went on to cause over a thousand cases and claim 216 lives.

Are there likely to be more cases?

It’s hard to know for sure because the illness can take up to 70 days to develop after contact with the bacteria. Public Health England is using genetic sequencing to try to identify other cases of infection that might be linked to the same outbreak.

Should I worry about getting infected?

The sandwiches responsible for this outbreak have been taken off the market, and most healthy people do not need to worry about listeria. Practising good food hygiene – such as careful washing of hands and food – can limit your risk of infection, and you can kill off any listeria bacteria in your food by cooking it thoroughly.