A farm in Nottinghamshire has been closed over fears of a second E coli outbreak.
The farm closed volutarily and a full investigation is being carried out.
The HPA said it was aware of two other cases potentially linked to the farm, but those cases were different strains of the bacteria.
An HPA statement said there were many potential sources of E coli and as yet there was no confirmation the farm was the source of infection.
“The majority of E coli outbreaks are caused either by food contamination or person-to-person spread and only about 1 in 50 of all cases are associated with outbreaks linked to petting farms,” the statement said.
“Where there are different strains of E coli involved, as there are in this case, there is uncertainty about whether there is a shared source of infection.
“The HPA has advised closure of the farm on a precautionary basis to protect the public health while the investigation continues.”
The closure of the farm comes after a farm in Surrey was found to be at the centre of an outbreak of E coli.