Description of the situation
06 April 1999
Disease Outbreak Reported
In March 1999 an influenza H5N1 virus was isolated from the feces of one goose during routine surveillance of ducks and geese. Preliminary characterization indicates that the haemagglutinin (HA) gene is 98.9% homologous with the H5N1 influenza virus isolate from a child in Hong Kong SAR in 1997 – A/Hong Kong/156/97. Although the neuraminidase (NA) is of the subtype N1 the internal genes are quite distinct from the 1997 H5N1 isolate and are most closely related to gene segments of influenza viruses isolated in the early 1990s from ducks in China and chickens in Italy. The pathogenicity in chickens of the H5N1 isolated in 1999 appears to be lower than that of the 1997 H5N1 isolates.