WNV Antibody Found In UK
Resident And Migrant Birds
From Patricia Doyle, PhD

Hello Jeff: As I've been saying since the beginning, I believe that NY 99 isolate West Nile LIKE virus in the Americas is far different from WNV seen around the world.
ProMed Mail
WNV Antibody Found In UK Resident/Migrant Birds
Evidence of the potentially deadly West Nile virus has been found in a high proportion of British birds, scientists have revealed. The virus is transmitted by mosquitoes and the researchers have warned that the risk of the virus spreading to humans is increasing with the impact of climate change.
There have been no cases of West Nile virus infection of humans in the United Kingdom but the virus caused the death of more than 270 people in the US last year.
Scientists at the Centre for Ecology and Hydrology [formerly the NERC Institute of Virology] in Oxford tested birds mainly in Cambridgeshire, but also in Dorset and South Wales. They found evidence of the virus in more than half the birds tested -- an "unexpectedly high" proportion, BBC science correspondent Christine McGourty said. It was found in more than 20 species in all, including crows, magpies, swallows, chickens, turkeys, and ducks.
While the birds were healthy and showed no symptoms, scientists did detect antibodies to the virus. This indicated the birds had come into contact with the virus and that their natural defences had successfully fought it off. It is thought that the virus is being brought into the country by migrating birds.
The researchers said there was no immediate threat to humans, but warned that climate change might increase the risk. The research, published on Sat 19 Jul 2003, comes after increased surveillance measures for the virus were introduced in the UK. The chief medical officer for England, Sir Liam Donaldson, announced the measures in early July, saying the risk to human health was low, but doctors and health officials had been urged to be on the look-out for symptoms.
ProMED-mail <>
[The publication referred to in this report was published on Fri 18 Jul 2003 in the online advance edition (JGV Direct) of the Journal of General Virology for October 2003 (Buckley A, Dawson A, Moss SR, Hinsley SA, Bellamy PE, Gould EA. Serological evidence of West Nile virus, Usutu virus and Sindbis virus infection of birds in the UK. <>).
The abstract of the paper reads as follows: "The introduction and rapid dispersal of the African flavivirus West Nile virus (WNV) throughout North America, and the high fatality rate due to encephalitis in birds, horses, other wildlife species and humans, has attracted major attention worldwide. Usutu virus, another flavivirus, came to prominence in 2001, when it was identified as the agent responsible for a drop in the bird population in Austria; previously this encephalitic virus was found only in birds and mosquitoes in Africa. Sindbis virus, a pathogenic alphavirus that causes arthritis, is widespread throughout Africa, Europe, Asia and Australia, infecting a range of arthropods and vertebrates and is genetically related to encephalitic viruses in North America. Currently there is no evidence that any of these viruses cause disease in the UK. Here the presence of virus-specific neutralizing antibodies is reported in the sera of resident and migrant birds in the UK, implying that each of these viruses is being introduced to UK birds, possibly by mosquitoes. This is supported by nucleotide sequencing that identified three slightly different sequences of WNV RNA in tissues of magpies and a blackbird. The detection of specific neutralizing antibodies to WNV in birds provides a plausible explanation for the lack of evidence of a decrease in the bird population in the UK compared with North America. The potential health risk posed to humans and animals by these viruses circulating in the UK is discussed."
The apparent absence of disease in arthropodborne virus infected British wild birds in contrast to the behavior of introduced West Nile virus in North America and Usutu virus in Austria is striking. To what extent this phenomenon may be due to genetic differences in the virulence of virus strains, to routes of transmission, or to vector specificity are intriguing questions for future analysis. - Mod.CP] ....................cp/sh
Patricia A. Doyle, PhD Please visit my "Emerging Diseases" message board at: Zhan le Devlesa tai sastimasa Go with God and in Good Health



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