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Useful Information

Influenza and Dengue Fever

27 May 2003

Dear Doctor,

In the wake of the Severe Acute Respiratory Syndrome outbreak in Hong Kong coming under control, we write to bring your attention to two important infectious diseases, namely influenza and dengue fever.

The Department of Health (DH) has been informed of recent localized outbreaks of influenza in the Guangdong Province, and the usual peak seasons of influenza in the Guangdong Province are June/July and November/December. In Hong Kong, our influenza surveillance data show that the usual peak season is during January and March, and, in the recent 6 weeks, the influenza-like illness consultation rates at the sentinel surveillance clinic network have been at baseline levels, and the public hospital admissions for influenza have been low. However, it would be prudent to be on the alert as there is frequent travel of people between Hong Kong and the Guangdong Province.

For dengue fever (DF), we first detected local cases in September 2002, and a record high of totally 20 local cases and 24 imported cases were recorded in 2002. So far this year, 13 (imported) cases have been notified to the DH, and this figure is more than double that in the corresponding period in 2002. Moreover, the monthly average ovitrap indices (which reflect the extensiveness of distribution of the vector mosquito Aedes albopictus) reported by the Food and Environmental Hygiene Department have risen sharply from 0.2% - 1.4% in the first quarter of 2003 to 11.4% in April 2003, though the index is lower than that in April 2002 (30.8%).

At present, the most effective strategy to control DF is to enhance disease surveillance and control the mosquito vectors. Please remain vigilant on the disease and notify the DH as early as possible. You may also help educate your clients to eliminate mosquito breeding places in their domestic environment and vicinity, and to take precautionary measures to prevent mosquito bite especially when travelling to DF endemic areas (e.g. South-east Asian countries).

You may wish to know that further information on the influenza surveillance results and health advice on prevention of influenza and dengue fever are available at the DH website http://www.chp.gov.hk . The DH pre-recorded health education hotline 2833 0111 also offers information and health advice on influenza and dengue fever.

We need your kind support in the control of infectious diseases in Hong Kong. Please notify DF cases, influenza-like illness outbreaks in institutions, and any unusual or unexplained pattern of illnesses to the respective Regional Office of the DH. The contact numbers are as follows:

11 Jan 2013