> The grebe was ‘collected’ on 28 July 2005 at a location where poultry had
> been dying of avian influenza since 15 July.
> The grebe was a juvenile and is reported to have shown no clinical
> symptoms of the disease.
> Subsequently hunters reported mass death of wild birds in the area.
> The obvious explanation — given the timing of the above and the fact the
> bird was a juvenile — is because the grebe had just been infected from
> a poultry source and hadn’t yet succombed to the virus when collected.

Although the above explanation looks most obvious, there may be yet
another possibility. If the bird was “collected” in live, it may have
been infected during handling (after vet’s exposure to poultry).
Since this was still in the early stage of Russian outbreaks, local
vets may have not been yet aware of how contagious this virus is.
We probably need to be extremely careful in interpreting “healthy wild
bird tested positive”.

Both vets and ornithologists should pay specialattention not to become “vectors” to wild individuals — this point is generally missing in guidelines (some only refer to prevention of human infections), and would be especially advisable to newly introduced areas or countries.