The largest outbreak of E. coli O157 linked to an Open Farm in the UK occurred at Godstone Farm, Surrey, in August and September 2009. There were 93 people affected, of whom 76 (82%) were under 10 years of age. Of the 78 people with symptoms, 27 (35%) were admitted to hospital and 17 (22%), all of them children, were diagnosed with HUS. Eight of the children with HUS required dialysis, some of whom have been left with permanent kidney damage.

The report of the independent investigation into the outbreak, the factors that contributed to it and its subsequent handling, has just been published. Led by George Griffin (Professor of Infectious Diseases and Medicine at St Georges University of London and Chair of the Advisory Committee on Dangerous Pathogens), the key findings are:

1. Farm operators should ensure that the layout and design of public areas are such that visitor contact with animal faecal matter (particularly ruminant) is minimised or eliminated.

2. There is a need to raise public awareness of the potential infection risks when arriving at a farm attraction, emphasising the parent/carers decision to allow children to have animal contact.

3. There should be a reassessment of the risk of E. coli O157 infection as low. Its probability may be low but the impact is high and the consequences very severe.

4. An Approved Code of Practice should be developed for the Open Farm industry, involving relevant authorities and in close consultation with leading representatives of the industry to underpin the industry's initiative in establishing an accreditation scheme.

5. The regulatory agencies and others should explore ways of working together in regulating Open Farms clarifying roles, responsibilities and relationships.

6. Research should be pursued to assist clinicians in the rapid diagnosis of E. coli O157 and the identification of and treatment for children likely to develop severe complications of the infection. Research should also be undertaken aimed at preventing or limiting carriage of the organism in animals.

Prof. Griffin stated that "This outbreak could very likely have been avoided if more attention had been given to preventing visitors being exposed to animal faecal matter. Once it had started, there is no doubt that even with prompt action this would have been a big outbreak. Nevertheless there was a lack of public health leadership by the Health Protection Agency and a missed opportunity to exercise decisive public health action and thereby restrict the size of the outbreak."

The assessment of risk carried out by Godstone Farm was inadequate and it principally relied on the actions of the public, primarily through handwashing, to control the risks. The risk assessment process used by the Local Authority did not facilitate the identification of hazards on the farm despite a programme of inspections.

It is currently very difficult for families to make their own informed decisions about the risk of visiting an open farm and better public education is crucial. In addition to public education on the risks of infection from E. coli O157, an accreditation scheme, led by the farming industry and informed by the regulators, would help the public identify which farm premises were operated to a known and acceptable standard.