CHARACTERIZATION OF AN AVIAN INFLUENZA-A (H5N1) VIRUS ISOLATED FROM ACHILD WITH A FATAL RESPIRATORY ILLNESS

An avian H5N1 influenza A virus (A/Hong Kong/156/97) was isolated from a tracheal aspirate obtained from a 3-year-old child in Hong Kong wit h a fatal illness consistent with influenza. Serologic analysis indica ted the presence of an H5 hemagglutinin. All eight RNA segments were d erived from an avian influenza A virus. The hemagglutinin contained mu ltiple basic amino acids adjacent to the cleavage site, a feature char acteristic of highly pathogenic avian influenza A viruses. The virus c aused 87.5 to 100 percent mortality in experimentally inoculated White Plymouth Rock and White Leghorn chickens. These results may have impl ications for global influenza surveillance and planning for pandemic i nfluenza.