Description of the situation
29 March 1999
Disease Outbreak Reported
On 26 March, authorities in Hong Kong SAR reported that an H5 virus was isolated on 10 March from cage swabs taken in the city's western wholesale poultry market, from a stall dealing only with imported waterfowl. It has not caused any illness in poultry in the market. The virus was immediately sent to local and international laboratories for further characterization. Even though the virus has the same haemaglutinin (H) and neuraminidase (N) subtype, it was found to be genetically distinct from the H5N1 virus found in 1997.
Local health officers visited the market following the incident and found that no workers reported any illness. Waterfowl are natural carriers of various influenza viruses, so that isolation of an H5 virus is not unusual and poses no public health risk on this occasion.
Import control and environmental monitoring of the market have taken place regularly since the importation of birds resumed in early 1998. This is the first time an H5 virus has been isolated. There is no evidence of infection with H5 virus in other poultry, nor in local farms. The supply of birds to Hong Kong SAR from any farm showing signs of infection will be suspended.