Five of the six upper respiratory tract infection cases in Tuen Mun Hospital have tested positive for human coronavirus OC43, a common cold virus.

The Centre for Health Protection said symptoms are mild and can include fever, runny nose and sore throat. The virus is usually transmitted through coughs and sneezes and the incubation period ranges from two to four days.

Initial tests gave negative results for Influenza A and B viruses and the SARS coronavirus.

As at noon today, there has been no new case. The six female patients, aged 19 to 29, who developed fever and respiratory tract infection symptoms between November 20 and 24 have no fever. Four of them are in stable condition while the other two are serious due to underlying illnesses.