The European Commission on Thursday urged people who recently visited Germany to watch for symptoms such as bloody diarrhoea after an outbreak of a food-borne bacteria blamed for two deaths.
The outbreak appears to be limited to Germany, but authorities are probing suspected cases in Sweden, Britain and the Netherlands among people who recently travelled there, the commission said.
"People who have recently visited Germany should pay attention to symptoms, such as bloody diarrhoea, and accordingly consult their physician," said Frederic Vincent, the commission spokesman for health issues.
The commission stressed that it was "essential" to rapidly identify potential cases "to prevent the development of severe disease."
German authorities believe raw vegetables are the most likely source of the outbreak of enterohaemorrhagic E. coli (EHEC), which causes haemolytic uraemic syndrome (HUS), a disease that can result in acute renal failure, seizures, strokes and coma.
The bacteria was found in three cucumbers from Spain, German authorities said Thursday.
Germany's national disease centre, the Robert Koch Institute, says that more than 200 people have been diagnosed as suffering from HUS, and that at least two people have died.