Listeriosis outbreak: Is it still safe to eat frozen vegetables?

Nine cases of listeriosis in Europe have resulted in death since 2015

A recent outbreak of listeriosis across Europe has been connected with the consumption of frozen vegetables that haven’t been cooked sufficiently.

News of the bacterial infection has led many to question whether it’s safe to eat frozen vegetables at all.

However, health organisations have stated that frozen vegetables, including frozen sweetcorn, can still be consumed if the correct precautionary measures are taken.

Here’s everything you need to know about the listeriosis outbreak, symptoms of the illness and whether it’s still safe to eat frozen vegetables:

What’s happened?

A number of health organisations, including the Food Standards Agency, the European Centre for Disease Prevention and Control and Public Health England, have issued warnings in regard to an outbreak of listeriosis across Europe, a bacterial infection caused by Listeria monocytogenes.

Listeria monocytogenes is a species of bacteria that can fester at very low temperatures.

The prevalence of listeriosis was previously linked to consumption of frozen sweetcorn.

However, it has now also been connected with other frozen vegetables that have been eaten without being cooked through thoroughly.

The outbreak of Listeria monocytogenes has been occurring throughout Austria, Denmark, Finland, Sweden and the UK since 2015.

According to the European Food Safety Authority (EFSA), there have been 47 cases of the illness as of 8 June 2018, nine of which have resulted in death.

Why has the outbreak occurred?

The root of the outbreak of listeriosis is currently being investigated by health experts, as stated by Dr Kathie Grant, head of the Gastrointestinal Bacteria Reference Unit at Public Health England.

“We have been working with partners to identify the cause of 11 cases of listeriosis dating back to 2015, which are part of a larger outbreak across Europe,” she said.

According to the EFSA, strains of the Listeria monocytogenes bacteria were found in frozen vegetables that had been produced by a Hungarian company in 2016, 2017 and 2018.

On 29 June 2018, the Hungarian Food Chain Safety Office organised for frozen vegetable products produced between August 2016 and June 2018 at the plant that had been affected to be withdrawn and recalled.

What are the symptoms?

In many cases, people exposed to listeriosis may not experience any symptoms at all, as Dr Grant explained.

“Most people won’t have any symptoms of the infection or will only experience mild symptoms such as vomiting and diarrhoea, which usually pass within a few days without the need for treatment,” she said.

“More serious infection can develop in those with weakened immune systems or in vulnerable groups including babies, the elderly or pregnant women.”

Other mild symptoms of listeriosis can include having a high temperature of 38C or above, having chills or experiencing aches and pains, as outlined by the NHS.

In more severe cases, symptoms such as acute headaches, seizures, blotchy rashes and difficulty looking at bright lights could be signs that the listeriosis has triggered meningitis.

In this instance, the NHS recommends calling 999 or going to A&E immediately.

How common is it?

Listeriosis is a rare illness, as stated by the Food Standards Agency (FSA).

However, it can be life-threatening for those with weakened immune systems, including the elderly and pregnant women.

The EFSA states that more cases could arise in the near future due to the long shelf-life of frozen vegetables, people eating frozen vegetables that haven’t been cooked properly and consumers eating frozen vegetables that were bought prior to the recalls of frozen produce.

How can you prevent it?

The first course of action is to make sure that you cook frozen vegetables properly before eating them, as outlined by Dr Grant.

“The best way to prevent listeriosis is to practise good food hygiene,” she said.

“Along with the FSA, FSS [Food Standards Scotland] and HPS [Health Protection Scotland], we are reminding people that most frozen vegetables, including sweetcorn, need to be cooked before eating.

“This includes if adding them to salads, smoothies or dips.”

This is the case even if a product is described as being ready-to-eat without cooking on the packaging.

Food products that have been noted as causing listeriosis in the past include soft cheeses such as camembert and brie, unpasteurised milk and chilled ready-to-eat foods, as highlighted by the NHS.

However, eating these foods won’t always result in listeriosis, as there’s only cause for worry if you begin exhibiting symptoms.