Press Release



AFD action in relation to the detection of H9


The following statement is issued by the Agriculture and Fisheries Department (AFD) today (Thursday) in response to press enquiries on AFD's action in relation to the detection of the H9 virus:

Influenza A H9 viruses are commonly found in poultry. A wide variety of birds including chickens, ducks, and geese may have exposed to it and develop antibodies. Since most birds are likely to be positive to the virus to various degrees, serological testing will not be able to differentiate birds that are actively shedding the virus.

As part of the influenza surveillance programme, AFD has been sampling from imported and local chickens for isolation of influenza viruses. Since December 1997, we have isolated H9 viruses from 24 samples. We are now working with local and overseas experts to compare these samples with the human isolate.

AFD will continue to sample from imported and local poultry and dispatch any influenza viruses isolated for further analysis. We are also paying particular attention to the daily cleaning programme of the market to ensure high hygiene standards are maintained.

In contrast, H5N1 virus is a very virulent virus. Chickens and other birds are not expected to have exposed and developed antibodies to the virus. AFD will continue to conduct serological testing at import control points and at local farms to screen out birds that tested positive to H5.

We will also closely liaise with the Department of Health in their investigation of the human cases.

End/Thursday, April 8, 1999