Supermarkets have recalled bags of frozen vegetables over fears they could contain a deadly bacteria called Listeria. Nine deaths in Europe – including two in the UK – have been linked to the outbreak, the Manchester Evening News reports.

The listeria bacteria can develop into the rare but serious listeriosis illness. It has symptoms that are similar to flu, including high temperature, muscle ache, sickness and diarrhoea. It can be more serious for people with weakened immune systems and also the elderly, pregnant women and infants.

A freezing plant in Hungary is thought to be the source of contamination, with two UK cases showing patients consumed the same brand of frozen corn from the same UK supermarket known to be supplied by Hungary.

The European Food Safety Authority (EFSA) said the extent of the outbreak had initially been underestimated, and recent cases showed it was continuing.

Listeriosis is a rare but serious foodborne illness caused by the bacterium Listeria monocytogenes that can be more serious for those individuals who have weakened immune systems, and also the elderly, pregnant women and infants.

The FSA has issued a list of 49 frozen food items – many sold across the big supermarket chains – that are all being withdrawn from sale.

It said: “The products might be contaminated with Listeria monocytogenes.

“Symptoms caused by this organism can be similar to flu and include high temperature, muscle ache or pain, chills, feeling or being sick and diarrhoea.

“Some people are more vulnerable to listeria infections, including those over 65 years of age, pregnant women and their unborn babies, babies less than one month old and people with weakened immune systems.