Another child is being treated in hospital following an outbreak of E. coli on a petting farm, the Health Protection Agency said today.
There are now 13 youngsters being cared for by doctors. Of these, four are seriously ill, six are in a stable condition and three are improving.
The total number of cases of E. coli 0157 linked to Godstone Farm in Surrey now stands at 37.
According to the Health Protection Agency (HPA), the outbreak could be the largest of its kind in the UK spread by animals.
A spokesman said: "The HPA reports that the total number of cases of E.coli O157 linked to Godstone Farm in Surrey is 37.
"Thirteen children are currently being treated in hospital."
Health officials were not able to release any information on the condition of the latest child to receive hospital treatment or where he or she was being treated.
The HPA said earlier it expected more cases to come to light because of the bug's long incubation period.
Tens of thousands of people could be affected, it has been reported.