Fighting Bangladesh’s Mosquito Menace

by Minoli de Soysa

Blocked drains, rotting garbage, stagnant pools, filthy lakes, an illiterate population - how can Bangladesh’s battle with the mosquito ever be won? Is it not a hopeless cause?

Certainly not, says the World Health Organization’s Environmental Health Officer in Bangladesh, Hans Heijnen, who gives his reasons why.

In the first place, all us who are panicking over the current influx of the winter mosquitoes can breathe easier - they may be a nuisance but they will not harm you because they carry no diseases. The winter mosquitoes are prolific because they are not fussy about where they breed and even prefer dirty places to clean ones. They cannot be eliminated completely from Dhaka, with its bad drainage system and stagnant water bodies.

The dengue mosquito, however, is a much fussier insect, insisting on clean, stagnant water to deposit its larvae. So after the heavy rains (turbulent water washes the larvae away) the dengue mosquito breeds happily in even a quarter inch of fresh, stagnant water left lying undisturbed for days in earthenware jars, metal drums, concrete cisterns, discarded tyres, food containers, flower vases and flower pots. August and September see an alarming rise in dengue cases in the cities of Bangladesh.

Of course, breeding grounds for the dengue mosquito are all found around the house and garden, right at your front door. So it is no use blaming the government for the clogged drains and rotting garbage because they do not contribute to the spread of the deadly Aedes aegypti mosquito that causes dengue.

"The fight against dengue has to be a community-based one. Everyone has to look after his or her own house and surroundings, as well as public places such as schools, offices and hospitals. Just walk around and empty any containers that have collected water," says Mr. Heijnen.

"What is needed most is a public awareness campaign to educate people on how to prevent mosquitoes from breeding in the first place,"  he points out. He gave the example of Colombo, Sri Lanka, where the city’s mayor went from house to house giving stickers to homes free of mosquito breeding grounds, a campaign covered by the media.

Mr. Heijnen stresses that fogging is not the answer. In addition to being bad for your health, it is effective only if sprayed directly in the house and garden, which many people do not allow for fear of contamination, he says.

The fight against dengue is a winnable one - and it is in our hands.

Unlike its cousin, the malaria mosquito is found in the countryside, particularly in forest areas. That is why it is advisable to take malaria medication before visiting the Chittagong Hill Tracts. As villages encroach on to forestland, the mosquito finds a new source of food -  human blood.

"In malaria areas, people are advised to sleep under nets impregnated with chemicals so that the mosquitoes die when they land on the nets," says Mr. Heijnen.

Dengue - Facts & Figures

	Dengue symptoms include high fever, severe headache, muscle and joint pain, nausea and vomiting.
	There are 50 million infections worldwide every year resulting in 24,000 deaths, mostly children.
	In the early 1950s, 13% of those infected died of dengue. The figure is now down to 0.3%.
	Two-fifths of the world’s population is at risk of infection.
	There are four different dengue viruses, so a person can be infected four times.
	A vaccine against all four viruses has been developed in Thailand and clinical trials are going on.