Hong Kong probes human case of avian flu

Dec 10, 2003 (CIDRAP News) – Health officials in Hong Kong are investigating a case in which a 5-year-old boy was infected with an avian influenza virus called influenza A(H9N2).

The boy was admitted to a hospital Nov 27 with fever, cough, and runny nose, the Hong Kong Department of Health said in a news release yesterday. He was discharged 2 days later and has recovered.

Dr. Thomas Tsang, a consultant with the health department, said influenza A(H9N2) viruses were isolated from a nasopharyngeal specimen from the boy. Further tests are being conducted to sequence the virus to confirm its identity.

Two girls in Hong Kong were infected with the same avian virus in 1999 and both recovered, Tsang said.

The H9N2 virus has been found in ducks and chickens for many years, but infection in humans is rare, the health department said. Tsang said an investigation of how the boy acquired the virus would focus on exposure to poultry and other birds. Officials said the boy had not traveled outside Hong Kong recently.

At least two other avian influenza viruses have crossed into humans in recent years. In Hong Kong in 1997, 18 human cases of H5N1 virus infection occurred, with six deaths. Two more H5N1 cases, one fatal, occurred there last February. Also, more than 80 people contracted the H7N7 avian virus (highly pathogenic avian influenza) last winter and spring when it infected many poultry flocks in the Netherlands. One man, a 57-year-old veterinarian, died of the infection.

None of the recent cases led to sustained person-to-person transmission. However, the cases have triggered concern that a new or mutating avian flu virus could spark a human epidemic or pandemic.

See also:

World Health Organization news release
http://www.who.int/csr/don/2003_12_10/en/

CIDRAP information on public health issues raised by Highly Pathogenic Avian Influenza