The Alert Response Level under the Government's Preparedness Plan for Influenza Pandemic is activated
Influenza (flu) is an acute illness of the respiratory tract caused by influenza viruses. In Hong Kong, it is usually more common in periods from January to March and from July to August.
For healthy individuals, seasonal influenza is usually self-limiting with recovery in 2 to 7 days. Symptoms may include fever, cough, sore throat, runny nose, muscle pain, fatigue and headache; some may also have vomiting and diarrhoea. Cough is often severe and prolonged but fever and other symptoms generally resolve in 5 to 7 days. However, influenza can be a serious illness to the weak and frail or elderly people, and may be complicated by bronchitis, chest infection or even death. The incubation period ranges from 1 to 4 days. Infected persons may pass the viruses to other people 1 day before and up to 5 to 7 days after they develop symptoms. The period may be even longer in young children or severely immunocompromised persons.
For more details on influenza and its prevention, please refer to Influenza.