Cases of Dengue fever are being reported from Delhi and Kolkata. As there is no vaccine, preventing mosquito bites is the only way to avoid the disease.
Dengue or "break-bone" fever is a viral disease found in tropical and sub-tropical areas. It is transmitted by the
mosquito. This insect bites during the day and is often found in and around human habitation. Symptoms of dengue include high fever, severe headache, cough, and joint and muscle pain. A rash often follows these symptoms. The acute illness can last up to ten days, and complete recovery can take two to four weeks.
Occasionally, a potentially fatal form of dengue called dengue hemorrhagic fever (DHF) occurs. DHF usually occurs in patients who have previously had dengue fever, and its fatality rate is about 5 percent.
Prevent mosquito bites.
Mosquitoes transmit many diseases that threaten travelers, and different mosquitoes bite at different times of the day. For example, the mosquitoes that spread malaria bite at night (from "dusk until dawn"), whereas the mosquitoes that spread dengue fever bite during the day.
Prevent bites while outdoors:
Wear light-colored clothing that covers most of the body (long sleeves and long pants).
Use insect repellent that contains DEET. Adults and children more than two months of age can use preparations containing up to 35% DEET - the higher the concentration, the longer it repels. Longer acting preparations are also available. Reapply after swimming or excessive sweating.
Prevent bites while you are indoors or asleep:
Check that there is fly-wire on the windows.
Use "knock-down" insect spray to kill mosquitoes in your room.
Use mosquito coils or electric insecticide vaporizers if mosquitoes can get into your room.
Note that air conditioning also repels mosquitoes.
Consider using a bed net impregnated with pyrethrin.