Press Release



Discovery of first cases of influenza A virus (H9N2) in humans in HK


The Government Virus Unit of the Hong Kong Department of Health (DH) had isolated, in collaboration with local and international health authorities, a new strain of influenza A virus (H9N2) from two patients recently.

"This is the first time H9N2 viruses, an avian influenza virus, are isolated from humans in Hong Kong," Deputy Director of Health, Dr Paul Saw said today (Wednesday).

The two patients are girls aged one and four who recovered fully from influenza-like illnesses last (March) month.

Atypical influenza viruses were picked up from their clinical specimens of throat secretion by the enhanced influenza surveillance system set up to monitor the avian flu situation in Hong Kong since late 1997.

The specimens were sent to World Health Organisation (WHO) Influenza Collaborating Reference Laboratories in United Kingdom and United States for further identification.

Results available today confirmed that the virus was influenza A (H9N2). The WHO was informed of the finding.

Speaking at a press briefing, Dr Saw said: "This influenza A (H9N2) is an avian influenza virus which has been isolated from duck and chicken for many years."

"Detailed investigations are underway to find out how the patients contracted the viruses."

"At this stage, the two cases appeared isolated. Notwithstanding this, the Department of Health's special investigation team on avian influenza will work closely with local and overseas experts to assess the global health impact of this new discovery and its mode of transmission."

"This information will be released to the medical professions and the public when available."

Dr Saw said that this virus is sensitive to the drugs amantadine and rimantadine.

He added that Hong Kong has a good medical and health system with adequate resources to provide appropriate treatment for this condition.

With the experience gained in the control of the avian flu outbreak in late 1997, he said that the Department would be better equipped to co-ordinate efforts from international health authorities and local experts to monitor and control the situation.

Members of the public are advised at this stage to observe good ventilation, to have proper diet, exercise and rest to build up body resistance to combat infection. They are also advised to wash their hands after handling poultry or the birds' excreta.

The public can obtain updated information on influenza from the Department of Health's Homepage ( They can also get information on the prevention of influenza from the Department's Central Health Education Hotline on Tel No: 2833 0111.

End/Wednesday, April 7, 1999