Public Health England investigated an initial cluster of the rare E. coli 055 in Dorset last year
A third child is being treated in hospital for serious kidney problems following an E. coli infection in Dorset.
Public Health England (PHE) said tests had shown it was the same strain of E. coli O55 that had affected 26 other people in the county.
In May, two children were also admitted to hospital with haemolytic uraemic syndrome (HUS), the most common cause of acute kidney injury in children .
No common source has been identified.
Animal droppings
PHE said close family contacts and pets were being tested and follow-up investigations were taking place.
It urged Dorset residents and visitors to be "extra vigilant" with hand hygiene before preparing food and after contact with animals.
In June, the O55 strain was found in animal droppings outside the home of an affected family.
It is not yet clear whether the faecal sample, which tested positive, came from a wild or domestic animal.
Noeleen McFarland, from PHE, said: "E. coli is a type of bacteria that is found in the guts of cattle and other ruminants, whilst pets can act as carriers passing this on to humans in their faeces, therefore hand hygiene is one of the most important ways of preventing this bacteria causing infection."
A cluster of cases of the bacterial illness in Dorset was investigated in November 2014, with another outbreak in May. There was also a further case in July.
Areas previously affected include Blandford, Portland, Bournemouth and Poole.
There have also been some cases outside the county which had links to people from Dorset.
Clusters of this particular strain had not been identified in England since records began in 1994.
PHE said any previous cases of the O55 strain had been associated with travel.
Avoiding E. coli infection
Wash hands thoroughly after using the toilet, before and after handling food and after handling animals
Remove any loose soil before storing vegetables and salads
Wash all vegetables and fruits that will be eaten raw
Store and prepare raw meat and unwashed vegetables away from ready-to-eat foods
Do not prepare raw vegetables with utensils that have also been used for raw meat
Cook all minced meat products, such as burgers and meat balls, thoroughly
People who have been ill should not prepare food for others for at least 48 hours after they have recovered
Source: Public Health England, external
- Published24 June 2015
- Published30 May 2015
- Published28 May 2015
- Published27 November 2014
- Published26 November 2014
- Published4 June 2011
