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FACTBOX-Five myths about mosquitoes and malaria

by Astrid Zweynert | azweynert | Thomson Reuters Foundation
Tuesday, 25 April 2017 15:24 GMT

A female Aedes aegypti mosquito is shown in this Center for Disease Control (CDC) photograph released to Reuters on October 30, 2013. CDC/Handout via Reuters/File Photo

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Malaria still kills more than 400,000 people a year despite significant recent success in bringing down the death toll.

LONDON, April 25 (Thomson Reuters Foundation) - Nearly half of the world's population is at risk of malaria, which is caused by parasites transmitted through the bites of infected mosquitoes.

Global efforts cut the malaria death toll by more than 60 percent between 2000 and 2015 but the disease still kills more than 400,000 people per year, mostly babies and young children in sub-Saharan Africa, according to the World Health Organization.

Here are some myths about malaria and mosquitoes:

MOSQUITOES ONLY BITE IN THE NIGHT

It depends on the type of mosquito.

The Anopheles mosquito that transmits malaria and the Culex that spreads the West Nile virus and lymphatic filariasis, which causes severe swelling in the arms, legs or genitals, mostly bite at night.

But the Aedes mosquito, which can spread viruses that cause dengue, zika, Chikugunya and rift valley fever, is active mostly during the day.

That makes it harder to control the diseases it spreads because bed nets, which have proved highly successful in reducing malaria cases, are not an effective protection tool.

THE RISKS ARE THE SAME FOR EVERYONE

Young children are much more vulnerable to all forms of malaria. Infants are more at risk because their immune systems are not yet fully developed, while in children under five they have not yet developed effective resistance to the disease.

There is some evidence that pregnancy, which increases body temperature and carbon dioxide emissions, may increase the likelihood of bites. Research in The Gambia showed the pregnant women in the study were twice as attractive to mosquitoes than non-pregnant women.

Researchers have also concluded that women in advanced pregnancy in rural areas in Africa tend to leave their huts at night more often because they need to urinate frequently.

YOU'RE SAFE IF YOU ARE IN AIR-CONDITIONED ROOMS

It is true that spending most of your time indoors, with doors and windows shut, will lower the risk of getting bitten by mosquitoes.

But some mosquitoes - like the Aedes aegypti which carries Zika and dengue - can live in nooks and crannies in homes and yards, for example under potted-plant containers and in boiler rooms.

That's why experts recommend to sleep under mosquito nets in high-risk areas even when air-conditioning is switched on.

BEING INFECTED ONCE MAKES YOU IMMUNE

It's true that people who have grown up in malaria-endemic areas, in particular if they were exposed as children, can gain some protection, but they can still get malaria, so it is not safe to assume that they do not need protection.

In addition, spending long periods of time in malaria-free areas makes immune people more susceptible to become affected again.

MOSQUITO EXTINCTION WOULD BE BEST

The high cost to human health and productivity from malaria has led some experts to suggest that mosquitoes should be eradicated altogether.

But there have been ethical objections to wiping out an entire species. And not all mosquitoes are a problem: Of about 3,000 varieties, only about 200 bite humans.

Some experts also argue against extinction because in many places, mosquitoes area are a vital source of food for animals, for example in the Arctic.

Scientists have been experimenting with gene technology to suppress mosquitoes to low enough levels to drive the malaria parasite extinct rather than the mosquito species itself.

 

SOURCES: WHO, Malaria Consortium, Roll Back Malaria (Reporting by Astrid Zweynert @azweynert , Editing by Ros Russell.; Please credit the Thomson Reuters Foundation, the charitable arm of Thomson Reuters, that covers humanitarian news, women's rights, trafficking, property rights, climate change and resilience. Visit http://news.trust.org)

Our Standards: The Thomson Reuters Trust Principles.

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