The woman was recovering in hospital after seeking treatment following her return from San Francisco with minor symptoms, RTHK said.

The latest case came nearly four weeks after officials here confirmed Asia's first case of the A(H1N1) virus, sparking the week-long quarantine of around 300 guests and staff at a city hotel.

More than 12,500 cases and 91 deaths have been recorded worldwide since A(H1N1) influenza emerged in Mexico and the United States a month ago. -- AFP