News / Health

Wind Offers Clue to Curbing Malaria

Study: targeting larval pools downwind from malaria hotspots could help control disease

Malaria is transmitted among humans by female Anopheles mosquitoes like this one.
Malaria is transmitted among humans by female Anopheles mosquitoes like this one.

Multimedia

Audio
Rosanne Skirble

A new malaria prevention strategy might literally be blowing in the wind.

A team of scientists studying the patterns of malaria infection in rural Kenyan villages noticed that, despite a gradual reduction of malaria cases in the region, “hotspots” persisted.



The blood-sucking mosquitos that transmit the malaria parasite to humans breed in water.

So the researchers decided to examine the location of those breeding ponds in relation to the most infected villages. Their findings are published this week in Nature Communications.

Co-author David Smith, an epidemiologist with the Johns Hopkins Bloomberg School of Public Health in Baltimore, Maryland, says a curious pattern emerged.

“In this study what we did is we looked at the locations of aquatic habitats and the locations of humans and we were trying to find out if there was some kind of clustering, which there should be and of course there was. But as we looked even closer what we found was that there was an association between the direction of the wind and the location of where people were at risk.”

Smith says while mosquitos aren’t particularly good flyers, their flight pattern is directed by the scent of a potential human host.

This mosquito larval habitat in Kilifi, Kenya, is also used for domestic purposes such as washing.
This mosquito larval habitat in Kilifi, Kenya, is also used for domestic purposes such as washing.

“We had a hypothesis that since scents travel down wind, that the mosquitos were actually tacking across the wind until they found one of those odor plumes and then tacking upwind until they found it. We should expect to find that places with higher risk were upwind of larval habitat.”  

Smith and his research team studied 642 children living in Kenyan villages after the rainy season, when malaria peaks.

Janet Midega is a medical entomologist with the Kenya Medical Research Institute and co-author of the study. She says scientists compared the malaria case data with the proximity of stagnant water pools. “What we did find was a lot of the pools of water did have immature mosquito stages, and so we sampled these pools of water. We sampled these mosquitos and identified them as the mosquito species that is responsible for malaria transmission in the area.”  

The study found that the shorter the distance from those larval incubators, the higher the prevalence of malaria.  

Smith says factoring wind into the equation makes it possible to target larval pools downwind from malaria hotspots and so control the disease at its source.

“And the philosophy here is just that knowing it better we might be able to predict the distribution of risk a little bit better, or at least understand what mosquitos are doing so that we can do a better job of distributing nets or interventions.”

Co-author Janet Midega says while plans are already underway to expand the study in Kenya, replicating it elsewhere presents an obvious challenge.  

“The applicability of the outcome of these results will be extremely dependent on the local conditions and the mosquitos that are common in that local environment so that control measures are tailored for the local epidemiological situation.”

So, Midega says, prevention strategies will depend on where you live, as some 30 to 40 different mosquito species transmit malaria.  Almost half the world’s population - about 3.3 billion people - is at risk.  In fact, the mosquito-borne parasitic disease strikes some 250 million people every year, and results in nearly one million deaths, largely in sub-Saharan Africa.

You May Like

IS Militants Release 49 Turkish Hostages

Turkey's state-run Anadolu news agency reports that no ransom was paid and no conditions accepted for the hostages' release; few details of the release are known More

Photogallery IS Attacks Send Thousands of Syrian Kurds Fleeing to Turkey

Syrian Observatory for Human Rights says more than 300 Kurdish fighters crossed into Syria from Turkey to defend a Kurdish area from attack by the Islamic militants More

Video Sierra Leone's Ebola Lockdown Continues

Thousands of health workers are going door to door in the West African country of 6 million, informing people of how to avoid Ebola, handing out soap More

This forum has been closed.
Comments
     
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Fears Ebola Outbreak ‘Beyond Our Capability to Contain’i
X
Jeff Seldin
September 20, 2014 10:28 PM
Each day brings with it new warnings about the deadly Ebola outbreak already blamed for killing more than 2,600 people across West Africa. And while countries and international organizations like the United Nations are starting to come through on promises of help for those most affected, the unprecedented speed with which the virus has spread is raising questions about the international response. VOA's Jeff Seldin has more from Washington.
Video

Video Fears Ebola Outbreak ‘Beyond Our Capability to Contain’

Each day brings with it new warnings about the deadly Ebola outbreak already blamed for killing more than 2,600 people across West Africa. And while countries and international organizations like the United Nations are starting to come through on promises of help for those most affected, the unprecedented speed with which the virus has spread is raising questions about the international response. VOA's Jeff Seldin has more from Washington.
Video

Video Iran, World Powers Seek Progress in Nuclear Talks

Iran and the five permanent members of the U.N. Security Council plus Germany, known as the P5 + 1, have started a new round of talks on Iran's nuclear program. VOA State Department correspondent Pam Dockins reports that as the negotiations take place in New York, a U.S. envoy is questioning Iran's commitment to peaceful nuclear activity.
Video

Video Obama Goes to UN With Islamic State, Ebola on Agenda

President Obama goes to the United Nations General Assembly to rally nations to support a coalition against Islamic State militants in Iraq and Syria. He also will look for nations to back his plan to fight the Ebola virus in West Africa. As VOA White House correspondent Luis Ramirez reports, Obama’s efforts reflect new moves by the U.S. administration to take a leading role in addressing world crises.
Video

Video Migrants Caught in No-Man's Land Called Calais

The deaths of hundreds of migrants in the Mediterranean this week has only recast the spotlight on the perils of reaching Europe. And for those forunate enough to reach a place like Calais, France, only find that their problems aren't over. Lisa Bryant has the story.
Video

Video Westgate Siege Anniversary Brings Back Painful Memories

One year after it happened, the survivors of the terror attack on Nairobi's Westgate Shopping Mall still cannot shake the images of that tragic incident. For VOA, Mohammed Yusuf tells the story of victims still waiting for the answer to the question 'how could this happen?'
Video

Video Militant Assault in Syria Displaces Thousands of Kurds

A major assault by Islamic State militants on Kurds in Syria has sent a wave of new refugees to the Turkish border, where they were stopped by Turkish border security. Turkey is already hosting about 700,000 Syrian refugees who fled the civil war between the government and the opposition. But the government in Ankara has a history of strained relations with Turkey's Kurdish minority. Zlatica Hoke reports Turkey is asking for international help.
Video

Video Whaling Summit Votes to Uphold Ban on Japan Whale Hunt

The International Whaling Commission, meeting in Slovenia, has voted to uphold a court ruling banning Japan from hunting whales in the Antarctic Ocean. Conservationists hailed the ruling as a victory, but Tokyo says it will submit revised plans for a whale hunt in 2015. Henry Ridgwell reports from London.
Video

Video A Dinosaur Fit for Land and Water

Residents and tourists in Washington D.C. can now examine a life-size replica of an unusual dinosaur that lived almost a hundred million years ago in northern Africa. Scientists say studying the behemoth named Spinosaurus helps them better understand how some prehistoric animals adapted to life on land and in water. The Spinosaurus replica is on display at the National Geographic museum. VOA’s George Putic has more.
Video

Video Iraqi Kurdistan Church Helps Christian Children Cope find shelter in churches in the Kurdish capital, Irbil

In the past six weeks, tens of thousands of Iraqi Christians have been forced to flee their homes by Islamic State militants and find shelter in churches in the Kurdish capital, Irbil. Despite U.S. airstrikes in the region, the prospect of people returning home is still very low and concerns are starting to grow over the impact this is having on the displaced youth. Sebastian Meyer reports from Irbil on how one church is coping.


Carnage and mayhem are part of daily life in northern Nigeria, the result of a terror campaign by the Islamist group Boko Haram. Fears are growing that Nigeria’s government may not know how to counter it, and may be making things worse. More

AppleAndroid