The Centre for Health Protection is enhancing influenza surveillance as Hong Kong enters the flu season.
The centre expects flu activity to rise in the coming weeks, saying this influenza season has arrived earlier than usual.
The positive percentage of seasonal influenza viruses among respiratory specimens increased from 8.44% to 12.03% from the week of April 16 to that of May 7.
Most detections were influenza A(H3), followed by influenza A(H1).
In the same period, the number of institutional outbreaks of influenza-like illness increased from one to 17.
In the past two weeks most outbreaks were reported by primary schools, followed by elderly-care homes.
The centre will issue letters to doctors, hospitals, institutions and schools appealing for heightened vigilance.
People are reminded to maintain good personal and environmental hygiene.
