Sun-dried tomatoes have been linked to an outbreak of potentially deadly hepatitis, according to health experts.
Seven people have developed symptoms of hepatitis A, which is infectious and can lead to fatal liver complications. Four of them were hospitalised but have since been given the all-clear.
Fears remain that contaminated products may still be on supermarket shelves or in consumer kitchens because experts are unable to carry out tests on food to identify which brand of sun-dried tomatoes is responsible.
The Government's Health Protection Agency (HPA) and the Food Standards Agency (FSA) are on the alert after two men and five women became ill. Four of the patients live in the East of England, two in London and one in the South-west.
The health alert was triggered when two of the cases were reported late last year to the HPA. The hepatitis A strain affecting them was identical to a strain from a previous outbreak associated with sun-dried tomatoes in the Netherlands.
Neither of the patients had travelled to a country with a high risk of hepatitis in the previous three months and both had eaten "substantial" amounts of sun-dried tomatoes.
The virus is carried by human faeces and can be passed on through contaminated food or water, especially as a result of poor hygiene during the preparation of food, and it is the only common food-borne disease preventable by vaccine.
Symptoms, which include aches, loss of appetite, abdominal discomfort, fever and fatigue, appear about 28 days after infection. Patients may also develop itchy skin and jaundice which can last several months.
Acute hepatitis A can develop into fulminant hepatitis A, in the most serious cases, in which toxins attack the liver, leading to life-threatening complications.
Hepatitis A is diagnosed by a blood test, but there is no treatment other than rest and fluids.
Writing in the medical journal Eurosurveillance, Carlos Carvalho of the HPA, said: "A single food source may be contaminated with more than one strain. A food-borne outbreak with multiple strains in at least two European countries is suspected."
A spokesman for the FSA said: "Sun-dried tomatoes are being investigated as one possible source of the hepatitis A cases. However, no food source has been conclusively identified and no other relevant cases have been reported in the UK."
By Janie Manzoori-Stamford
E-mail your comments to Janie Manzoori-Stamford here.
Looking for a new job? Find your next job here with Catererandhotelkeeper.com jobs