The infant tested positive to the H9N2 strain of avian influenza, Thomas Tsang, controller for Hong Kong's Centre for Health Protection, said at a press conference in the city today. The strain of bird flu is a milder form than the H5N1 virus that has infected almost 300 people since 2003.

The infant may have contracted the virus from live poultry in a stall at a wet market in Tseung Kwan O, in the city's northeast, Tsang said. The H9N2 virus is rarely transmitted to human beings, he said.

The girl, whose condition is stable, is being monitored in an isolated unit at the city's Princess Margaret Hospital, according to a statement from the city's Hospital Authority. She has a running nose and a normal body temperature, it said.