Suspect H5N1 at Second Suffolk Farm
Recombinomics Commentary
November 15, 2007
Around 30 dead birds were found at Grove Farm in Botesdale, which is one of the farms closest to Sunday's H5N1 outbreak at Redgrave Park farm.
There are around 5,500 turkeys at Grove Farm, where tests are currently being carried out to see if it is the deadly H5N1 strain.
The Grove Farm turkeys were due to be culled as a precautionary measure after Defra assessed they had had "dangerous contact" with the initial case of the virus.
But overnight the cull became one of "slaughter on suspicion" when animal health officials turning up to kill the birds found a number of them had already died.
The above comments suggest H5N1 has spread to a second farm. Although this farm was one of four farms under suspicion because of workers in common with the Redgrave Park outbreak (see satellite map), Botesdale is also adjacent to the large ornamental lake on the premises of Redgrave Park.
Test results on the dead birds, as well as adjacent farms will be of interest. The poultry density in this area is high, and H5N1 frequently produces asymptomatic infections in waterfowl, including a crested grebe in Russia and a teal in Egypt). Although clade 2.2 sequences have been obtained from the asymptomatic birds, detection is difficult. Antibody tests measure prior exposure and recovery, which would more accurately defined the risk of H5N1 transport and transmission by wild birds. The sequences detected in Suffolk are similar to sequences from grebes and swans in Tyva and Mongolia which died during a massive outbreak in the spring and summer of 2006.
Although the failure to detect H5N1 in wild waterfowl is frequently cited by wildlife conservation groups, most of the surveillance testing in waterfowl does not include antibody testing, which would more accurate reflect the extent of H5N1 in wild birds.
Antibody testing of wild birds in Russia routinely generates positive results, which was also found in commercial ducks in Bavaria this summer.
Media Links
Recombinomics Presentations
Recombinomics Publications
Recombinomics Paper at Nature Precedings