Farmers’ leaders have expressed incredulity and concern that a government-funded research laboratory has emerged as the most likely source of the foot-and-mouth virus.

An investigation by the Health and Safety Executive identified two potential routes by which the virus may have escaped from the Institute of Animal Health’s research site at Pirbright.

The first is a possible breakdown in the processing of potentially infected effluent. The second is that the virus was released, accidentally or deliberately, by staff at either IAH or animal health company Merial, which share the site.

Both collaborate to perform investigative work on the foot-and-mouth virus, and were working on the strain known to be the cause of infection during the period 14-25 July when the release is believed to have occurred.

Pirbright theory

Based on: HSE www.hse.gov.uk/news/archive/07aug/pirbright.html

Merial had produced a large quantity of the virus (10,000 litres) and IAH was conducting a series of small-scale experiments. Further gene analysis is being performed to establish if either is the sole source of the outbreak.

The HSE reported its initial findings to DEFRA on Tuesday (7 August). It described as “negligible” the possibility that the virus escaped from the site via either waterborne or airborne transmission routes, but said “release by human movement must be considered a real possibility”.

HSE lead investigator Paul Logan said he saw no reason to stop the IAH operating at the site, providing biosecurity protocols are followed rigorously. “The situation regarding Merial is less clear cut the report indicates there are doubts about the integrity of the drainage system, including pipework which leads to the final treatment plant.” Further investigation was necessary he said.

Merial was quick to defend its procedures. “We ensure that the water used in virus production is treated, we then transfer it to IAH who treat it further and release it.”

NFU president Peter Kendall said farmers he had spoken to were “horrified” that Pirbright could be the source of the outbreak.

“The findings of this interim report are vitally important. However, I am sure it will only add to the frustration and anger of farmers across the country. I have spoken to many farmers over the past few days who are absolutely horrified that the source of the outbreak could be Pirbright.”

andrew.watts@rbi.co.uk