Nearly 300 individuals in Europe and the UK have fallen ill in a significant outbreak of potentially fatal food poisoning connected to tainted tomatoes.

Almost 30 cases have been recorded in Britain, with the UK Health Security Agency warning that the rare strains involved are particularly severe. 

At least 14 patients across the outbreak have required hospital treatment.

Health authorities have confirmed 289 cases of infection since January of the previous year, due to two rare strains of the bacteria, identified as Salmonella Blockley and Salmonella Strathcona.

Testing conducted by the European Food Safety Authority (EFSA) in 2023 and 2024 traced the contamination back to cherry tomatoes cultivated in Sicily, Italy.

Italy has the highest patient count, with 78 cases documented, followed by Germany, Austria, and France. The United States has also reported eight cases, and Canada has confirmed five.

The European Centre for Disease Prevention and Control (ECDC) stated that the risk persists as long as contaminated seasonal produce is distributed to stores, indicating the threat is ongoing.

A spokesperson mentioned, ‘Future outbreaks are expected until the source of the contamination is discovered and preventive measures are established.’

Salmonella can trigger diarrhoea, vomiting, stomach cramps and fever, and in the most severe cases can lead to life-threatening complications.

Italian health chiefs have already rolled out an urgent sampling and testing programme on two varieties of cherry tomatoes sold domestically, requiring local authorities to complete at least one round of checks by the end of 2024.

Experts say tomatoes may be especially vulnerable because of their texture, which allows bacteria to cling to the surface. 

The danger is heightened as they are often eaten raw rather than cooked, which would normally kill off harmful bugs.

Salmonella is a group of bacteria that infects the gut of farm animals and is usually associated with meat, poultry and eggs. 

While most cases clear within days, it can sometimes prove fatal.

Symptoms usually appear within 12 to 72 hours of infection. Those most at risk of severe illness include children, the elderly and anyone with a weakened immune system. 

In serious cases, patients may need hospital care because of the risk of dehydration.

It comes as UKHSA data released earlier this year found salmonella cases have surged in the first three months of 2025, up on 2023 and 2024. 

According to the ECDC and the EFSA, nine European countries have reported 29 cases of Salmonella Strathcona since January 2025.

Tomato consumption was reported by four people who were sickened by the bug, with Italy reporting the most infections with 11 people sick.

Experts say that isolates genetically close to the bacteria causing the outbreak which has swept through Europe and the US have been detected since 2011 – indicating a recurrent public health concern.

The ECDC added that it is an ongoing seasonal outbreak, with most cases occurring in the summer months when foodborne illnesses are more common, particularly between June and October.

It added: ‘The recurrence of cases in 2025, including those without travel history, suggests ongoing transmission and distribution of contaminated produce beyond Italy. The presence of cases in multiple countries underscores the need for continued surveillance and cross-sector coordinated response.’

According to the ECDC, the role of the environment should also be investigated to identify the point of entry at which contamination with Salmonella Strathcona is occurring.