AS scientists work round the clock to identify the source of a new strain of E.coli, health chiefs in Yorkshire have offered advice to residents.
So far, the E.coli strain has infected 1,600 people worldwide, including seven in the UK.
All the UK cases caught the infection in Germany, where the outbreak began. The strain has killed at least 18 people.
Researchers suspect raw tomatoes, cucumbers and lettuce may be the source.
Dr Suzanna Mathew is the consultant in communicable disease control and regional gastrointestinal lead for the Health Protection Agency (HPA) in Yorkshire and the Humber.
She said: “The HPA continues to actively monitor the situation very carefully and is working with the authorities in Germany and with counterparts across Europe as to the cause of the outbreak.
“Health professionals nationally have been alerted to the situation and advised to urgently investigate and report suspected cases with a travel history to Germany.”
The World Health Organisation (WHO) has said it is conducting “numerous investigations” into what they describe as Europe’s worst recorded food-poisoning outbreak.
The HPA has issued a warning to people travelling to Germany to avoid eating raw tomatoes, cucmbers and leafy salads including lettuce.
Officials have urged anyone returning from germany with an illness, including bloody diarrhoea, to seek medical attention.