27.05.2011

As part of routine surveillance for avian influenza viruses from December 2008 through January 2009 in eastern China, tracheal and cloacal swab samples from apparently healthy domestic ducks in live poultry markets were collected for virus isolation and identification. From these samples, 2 influenza (H5N5) viruses—A/duck/eastern China/008/2008 (008 [H5N5]) and A/duck/eastern China/031/2009 (031 [H5N5])—were detected in mallard ducks (Anas platyrhynchos). During testing they were highly pathogenic in chickens and moderately pathogenic in mice. The two new viruses are probably reassortants of Eurasian virus strains and that H5N1 subtypes could have provided their backbones. The researchers said the findings highlight the importance of ducks as vessels for creating new flu virus subtypes, and that, given free-range duck farming practices, the new strains could pose a threat to other poultry or to humans (Emerging Infectious Diseases, June 2011).