The respiratory illness outbreak at the Caritas Medical Centre has been confirmed to be parainfluenza virus type 4, the Centre for Health Protection says.

Laboratory tests performed by the University of Hong Kong showed 19 of the 34 children involved in the outbreak were infected by the virus. Only one still has a fever, and tests on more samples are continuing.

Last night, two other patients, an 11-year-old boy and a 13-year-old girl, were found to have fever and upper respiratory infection symptoms. Specimens have been taken to find the cause of infection.

The centre and the Hospital Authority are closely monitoring the situation and the implementation of infection control measures.