Nov 13, 2007 (CIDRAP News) – The avian influenza virus found this week in turkeys at a farm in Suffolk, England, is the lethal H5N1 variety, veterinary officials announced today.
Laboratory experts are still running tests on the samples to gain clues about the strain's origin, according to a press release today from the United Kingdom Department for Environment, Food and Rural Affairs (DEFRA). The farm is located near Diss, about 107 miles northeast of London.
Authorities have declared a 3-kilometer protection zone and a 10-kilometer surveillance zone around the farm, plus a much wider restriction zone. Farmers in the zone are required to isolate poultry from wild birds, and movements of birds out of the zone are banned. DEFRA also banned bird-related gatherings in England, including bird shows and pigeon racing.
The BBC said 6,500 poultry at the farm would be culled. The farm produces mostly turkeys but also raises ducks and geese.
"A full epidemiological investigation and tracings of any dangerous contacts are underway and all possible sources of the outbreak will be investigated," the DEFRA statement said.
Fred Landeg, DEFRA's acting chief veterinary officer, told BBC News today that initial genetic sequence data suggest that the outbreak strain is closely related to H5N1 viruses found recently in the Czech Republic and Germany, "which does suggest a possible wild bird source."
"However, at this stage we are looking with an open mind as to the origin, and all potential sources of the origin will be investigated," Landeg said.
Previous news reports said the turkeys were free-range, which could have allowed them to come into contact with wild birds. Landeg said there is a lake at the affected farm that attracts a number of wild fowl, the BBC reported.
Wild birds were initially suspected as the cause of an H5N1 outbreak in February at the Bernard Matthews turkey farm in another part of Suffolk, about 70 miles from London, but officials said later that the source was probably contaminated turkey meat imported from Hungary.
The H5N1 findings at the Matthews farm represented the first outbreak of the lethal virus in British poultry. However, authorities also identified the virus in a wild swan that washed up on a Scottish shore in 2006 and in an imported pet bird in 2005.
Today's confirmation of H5N1 represents yet another infectious disease setback for Britain's farmers. A laboratory leak of the foot-and-mouth disease virus from a vaccine research and production facility sparked outbreaks at five cattle farms in August and September. Veterinarians have also recently reported outbreaks of bluetongue disease in English cattle herds.
Nov 12 CIDRAP News story "UK reports H5 flu outbreak in turkeys"