Avian influenza in Mongolia

From Promed: "The Mongolian case provides the best evidence to date for wild birds in the trans-boundary spread of H5N1 avian influenza ..."

This is a snippet of a longer post by Les Sims, Asia Pacific Veterinary Information Services. I totally agree - without large numbers of poultry in Mongolia, these isolations demonstrate that a wild bird population can host H5N1 in the absence of affected poultry. However, I think it remains to be seen how long the virus will persist. Is the basic reproductive ratio (a function of mortality rate, contact rates, length of viral shedding and other things) of H5N1 in wild migratory birds sufficiently high to maintain the virus in the long term? I just don't think we know the answer to this yet.