Discovery of a dead bar-headed goose in Qinghai province (where major outbreak, killing thousands of wild birds, in spring last year), raises many questions.
One possibility - far from confirmed as yet - is that could be related to waterbirds being artificially reared.
Then, various questions - here from Richard Thomas of Birdlife International:
The rediscovery of H5N1 in Qinghai a year after the first report is indeed intriguing and throws up many questions. It recalls the two outbreaks in Lhasa poultry market, in January 2004 and then again, more than a year later, in August 2005. Both of these were traced back to the city of Lanzhou, according to FAO. [Indeed, according to ProMed, FAO traced the second of these outbreaks back to a commercial poultry factory in the city].
Were genetic tests carried out on either of the two Lhasa outbreaks to find out which strain was involved? Given the proximity of Lanzhou to Qinghai, and Lanzhou's key position on the Silk Road, I'd be very surprised if the strain wasn't the Qinghai strain, but it would be good to have this confirmed.
What was done to "clean up" Lanzhou after the 2004 outbreak was traced back there, and why did it fail (again) in 2005 (or did the city keep producing infected poultry/animal feed for 20 months)? Were any restrictions placed on poultry and chicken manure-based animal feed/fertiliser movements from Lanzhou in the mean time, particularly exports along the railway line to Eastern Europe?
Did the Bar-headed Geese in 2006 catch the virus because it survived in the environment from 2005, because Lanzhou re-supplied it into the environment (for example in infected chicken manure-based animal feed/fertiliser produced there), or because of on-going infections in wild bird populations? [Do we know if the dead geese actually had the virus, or antibodies to it? If the latter, they could be survivors from 2005 that died of other causes].
So many questions...I'm sure someone has the answers to at least some of them.
Post edited by: martin, at: 2006/05/18 08:45