For some mosquito-transmitted disease, there are no known drug treatments or vaccines, so prevention becomes extremely important. This is particularly true for dengue fever which occurs widely in the tropical regions including certain areas of Singapore. Fortunately, as a result of stringent checks by the Ministry of Environment, the incidence of dengue in Singapore has been decreasing. Dengue, also called breakbone fever, occurs about 5-8 days after being bitten by an Aedes mosquito infected with the virus. Symptoms include severe splitting headaches, fever, backache, retro- pain and leg and joint pains. Occasionally the illness is complicated by a bleeding tendency and is then called dengue hemorrhagic fever which sometimes can be fatal. Although treatment is entirely symptomatic, it is important to consult your doctor early to prevent complications.

What can be done to prevent mosquito-borne diseases?

The following measures are recommended to reduce the changes of getting mosquito-borne diseases, including malaria, filariasis, Japanese encephalitis and dengue:

1) The aedes mosquito breeds in an urban environment in water-filled empty tins, old tires, drains and plant saucers. Removing standing water of all forms from an area restricts breeding.

2) Regular fogging against resting adult mosquitoes in dwellings and gardens is recommended.

3) If you are not staying in a closed, air-conditioned facility when traveling, then correct use of mosquito nets is important. For added protection for up to 3 months or longer, mosquito nets can be soaked in a 1% solution of permethrin or other repellent/insecticide. If you plan to reside in a malarious area, the curtains can be treated in a similar manner. All windows and doors should be screened and all cracks in the building sealed.

4) Use mosquito coils or "knockdown" sprays in wardrobes and under the bed before retiring for the night.

5) Wear clothing with long sleeves and long pants after dusk. Avoid wearing dark colored clothing and using perfumes and colognes since these may attract mosquitoes.

6) Use effective mosquito repellents on exposed skin and clothing containing at least 30% diethyltoluamide (deet) especially during evening and night hours. These must be reapplied regularly to maintain their effectiveness. In rare cases deet can cause reactions, particularly with prolonged or excessive use by children or in higher concentration.

7) Use an electric fan at night to help discourage mosquitoes from settling.

These measures will substantially reduce but not eliminate the risk of mosquito-borne diseases. These measures should also be combined with the regular use of suitable antimalarial prophylaxis when traveling in epidemic areas.