Poultry vaccination may hamper avian influenza detection

Influenza experts pondering the relative failure of the H5N1 avian influenza virus to spread among humans believe that problems in monitoring the situation are made worse by the success of local poultry vaccination programs. Angus Nicoll, influenza project coordinator at the European Center for Disease Prevention and Control (ECDC), believes that low levels of the virus may be causing outbreaks, without the sudden deaths of large numbers of chickens or other farmed birds acting as warning signs.

An outbreak of human-transmitted bird flu on the Indonesian island of Sumatra in May prompted the World Health Organization to put its global stockpile of Swiss drug major Roche's Tamiflu (oseltamivir) on alert, however, the cluster was confined to a single family.