U.N. warns of new avian flu strain

The United Nations Food and Agriculture Organization (FAO) said on Monday that a recently-emerged strain of avian influenza in Asia presents a new threat to animals and should be closely monitored.

The flu strain, known as A(H5N6), has already been detected in poultry in China, Laos and Vietnam.

"Influenza viruses are constantly mixing and recombining to form new threats," Juan Lubroth, the FAO's chief veterinary officer, said. "However, H5N6 is particularly worrisome, since it has been detected in several places so far from one another, and because it is so highly pathogenic, meaning infected poultry quickly become sick and, within 72 hours, death rates are very high."

Despite the discovery of A(H5N6) in poultry in multiple countries, only one human case in China has been reported.

"This suggests that the virus does not easily jump from animals to humans," Elizabeth Mumford, an epidemiologist with the World Health Organization, said. "Of course, we still need to remain vigilant, because prevalence in poultry and therefore human exposure could increase during the winter."

The FAO urged countries in Southeast and East Asia, especially those with links to the poultry trade, to step up efforts to detect and report influenza viruses in poultry and monitor for any human cases.