Gene sequencing of H9N2 virus shows avian origin

7 Jan 2009

The Centre for Health Protection (CHP) of the Department of Health today (January 7) completed gene sequencing on an influenza A (H9N2) virus found in a two-month-old girl in December 2008 and the results indicated all the genes were of avian origin.

A CHP spokesman said all the eight genes of the virus sample taken from the girl had been sequenced.

"DNA sequences of the genes concerned show that they are of avian origin and re-assortment with genes of human influenza origin has not been found.

"The virus is highly similar to the H9N2 virus isolated from another case involving a nine-month-old girl in 2007," he said.

The spokesman noted that the virus found in the two-month-old girl was sensitive to Tamiflu and Amantadine , two kinds of antiviral medicines.

The girl is still under treatment in Tuen Mun Hospital for another disease. Her symptoms of H9N2 infection have subsided. Nasopharyngeal aspirate specimens taken from the girl on January 2 were tested negative for influenza A H9N2.

All close contacts of the girl did not developed symptoms of H9N2 infection.

"The epidemiological and genetic findings so far suggest that the H9N2 virus has shown no signs of increased risk for human-to-human transmission," the spokesman said.