Five patients aged 27 to 79 in Tai Po Hospital's male psychiatric ward have tested positive for influenza-A. They are stable.

The men have come down with flu-like symptoms since August 21. Four are being treated in isolation while one was transferred to Alice Ho Miu Ling Nethersole Hospital. They tested negative for human swine flu.

The hospital has enhanced infection control measures in the ward, suspending admissions and visits. All patients in it are under close surveillance.

The cases have been reported to the Hospital Authority and the Centre for Health Protection.