News / Africa

Killing Mosquitoes Early On

A young girl with malaria rests in the inpatient ward of the Malualkon Primary Health Care Center in Malualkon, in the South Sudanese state of Northern Bahr el-Ghazal, June 1, 2012.
A young girl with malaria rests in the inpatient ward of the Malualkon Primary Health Care Center in Malualkon, in the South Sudanese state of Northern Bahr el-Ghazal, June 1, 2012.

Multimedia

Audio
  • Listen to De Capua report on controling mosquitoes with LSM

Joe DeCapua
Targeting mosquitoes in their early stages of life has the potential to greatly boost malaria control efforts and prevent thousands of new infections every year. A new study looks at the effectiveness of – what’s called -- larval source management or LSM. It’s estimated malaria causes 660,000 deaths every year, mostly in sub-Saharan Africa and Asia.


Currently, the main malaria preventive measures are long-lasting insecticide-treated mosquito nets and the indoor spraying of homes. But mosquitoes are building up resistance to the chemicals. That’s one reason why researchers reviewed 13 studies of LSM from Eritrea, Kenya, The Gambia, Mali, Tanzania, the Philippines, Sri Lanka and Greece.

Lucy Tusting -- an epidemiologist at the London School of Hygiene and Tropical Medicine -- is the lead author of what’s called The Cochrane review.

“This research was important because a number of malaria endemic countries in sub-Saharan Africa and elsewhere are currently using larval source management. But there’s a real lack of consensus on how effective the method can be and in which settings it’s appropriate. And few studies have so far been conducted to rigorously evaluate the intervention,” she said.

Eliminating mosquitoes before they’re able to transmit the parasite would – on the surface – appear to be a valuable addition to any control program. But Tusting said it’s not a simple decision.

“First of all, we do have very, very effective existing methods of malaria control. Long-lasting insecticide treated nets and indoor residual spraying are both highly effective, rolled out in a vast scale across Africa and elsewhere. And they’ve been undoubtedly a major reason for the successes in malaria control in the last decades. So I think with that in mind there’s been less need to look at other alternative interventions.”

The World Health Organization has issued guidelines on the use of LSM. Currently, the WHO does not recommend using the larvicides in rural sub-Saharan Africa, unless there are particular circumstances that limit the habitats of mosquito larvae. The guidelines say, “Larviciding should be considered for malaria control -- with or without other interventions -- only in areas where the breeding sites are few, fixed and findable.”

The guidelines add, “In most endemic settings, the appropriate way to use larviciding is as a supplement” to nets and spraying. The WHO says, “Larviciding measures may be effective as the leading method of vector control in urban areas.”  However, it says “more good quality evidence is needed to support this view.”

Tusting explained how larval source management works.

“Malaria is transmitted by mosquitoes,” she said, “The mosquitoes lay their eggs in standing water and the eggs then hatch and develop into larvae, which then develop into flying adult mosquitoes, which are capable of transmitting malaria. So, larval source management is a method of controlling malaria that works by targeting those immature mosquito stages that are found in standing water.”

Long-lasting insecticide treated nets and residual indoor spraying take aim at adult mosquitoes. Tusting said that LSM would be used in combination with these methods, not in place of them. There are several ways of using larval source management, which could be especially effective in urban areas.

“So, for example, by permanently removing standing water – by draining or filling land – or by making temporary changes to mosquito habitats to disrupt their breeding, for example, by clearing drains to improve water flow. Another common method is larviciding in which chemicals or biological larvicides are added to standing water to kill larvae,” she aid.

Tusting said some research indicates the cost of LSM would be comparable to that of nets and spraying. According to the Roll Back Malaria Campaign, the total cost of the global strategy against the disease is between five and six billion dollars a year.

Her colleague and co-author, Durham University Professor Steve Lindsay, called the review a “landmark publication demonstrating that in many places larval source management should be used as a supplementary weapon against malaria.”

The review says LSM, in appropriate settings, could reduce malaria cases by up to 75 percent and the proportion of people infected with the malaria parasite by 90 percent.

You May Like

Turbulent Transition Imperils Tunisia’s Arab Spring Gains

Critics say new anti-terrorism laws worsen Tunisia's situation while others put faith in country’s vibrant civil organizations, women’s movement More

Burundi’s Political Crisis May Become Humanitarian One

United Nations aid agencies issue warning as deadly violence sends tens of thousands fleeing More

Yemenis Adjust to Life Under Houthi Rule

Locals want warring parties to strike deal to stop bloodletting before deciding how country is governed More

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Texas Town Residents Told to 'Just Leave' Ahead of Flood Threati
X
Greg Flakus
May 29, 2015 11:24 PM
Water from heavy rain in eastern and central Texas is now swelling rivers that flow into the Gulf of Mexico, threatening towns along their banks. VOA’s Greg Flakus visited the town of Wharton, southwest of Houston, where the Colorado River is close to cresting.
Video

Video Texas Town Residents Told to 'Just Leave' Ahead of Flood Threat

Water from heavy rain in eastern and central Texas is now swelling rivers that flow into the Gulf of Mexico, threatening towns along their banks. VOA’s Greg Flakus visited the town of Wharton, southwest of Houston, where the Colorado River is close to cresting.
Video

Video New York's One World Trade Center Observatory Opens to Public

From New Jersey to Long Island, from Northern suburbs to the Atlantic Ocean, with all of New York City in-between.  That view became available to the public Friday as the One World Trade Center Observatory opened in New York -- atop the replacement for the buildings destroyed in the September 11, 2001, attacks.  VOA’s Bernard Shusman reports.
Video

Video Seoul Sponsors Korean Unification Fair

With inter-Korean relations deteriorating over the North’s nuclear program, past military provocations and human rights abuses, many Koreans still hold out hope for eventual peaceful re-unification. VOA’s Brian Padden visited a “unification fair” held this week in Seoul, where border communities promoted the benefits of increased cooperation.
Video

Video Purple Door Coffeeshop: Changing Lives One Cup at a Time

For a quarter of his life, Kevin Persons lived on the street. Today, he is working behind the counter of an espresso bar, serving coffee and working to transition off the streets and into a home. Paul Vargas reports for VOA.
Video

Video Modular Robot Getting Closer to Reality

A robot being developed at Carnegie Mellon University has evolved into a multi-legged modular mechanical snake, able to move over rugged surfaces and explore the surroundings. Scientists say such machines could someday help in search and rescue operations. VOA’s George Putic reports.
Video

Video Shanghai Hosts Big Consumer Electronics Show

Electronic gadgets are a huge success in China, judging by the first Asian Consumer Electronics Show, held this week in Shanghai. Over the course of two days, more than 20,000 visitors watched, tested and played with useful and some less-useful electronic devices exhibited by about 200 manufacturers. VOA’s George Putic has more.
Video

Video Forced to Return Home, Afghan Refugees Face Increased Hardship

Undocumented refugees returning to Afghanistan from Pakistan have no jobs, no support system, and no home return to, and international aid agencies say they and the government are overwhelmed and under-resourced. Ayesha Tanzeem has more from Kabul.
Video

Video Britain Makes Controversial Move to Crack Down on Extremism

Britain is moving to tighten controls on extremist rhetoric, even when it does not incite violence or hatred -- a move that some are concerned might unduly restrict basic freedoms. It is an issue many countries are grappling with as extremist groups gain power in the Middle East, fueled in part by donations and fighters from the West. VOA’s Al Pessin reports from London.
Video

Video 3D Printer Makes Replica of Iconic Sports Car

Cars with parts made by 3D printers are already on the road, but engineers are still learning about this new technology. While testing the possibility of printing an entire car, researchers at the U.S. Department of Energy recently created an electric-powered replica of an iconic sports roadster. VOA’s George Putic has more.
Video

Video Al-Shabab Recruitment Drive Still on In Kenya

The al-Shabab militants that have long battled for control of Somalia also have recruited thousands of young people in Kenya, leaving many families disconsolate. Mohammed Yusuf recently visited the Kenyan town of Isiolo, and met with relatives of those recruited, as well as a many who have helped with the recruiting.
Video

Video A Small Oasis on Kabul's Outskirts Provides Relief From Security Tensions

When people in Kabul want to get away from the city and relax, many choose Qargha Lake, a small resort on the outskirts of Kabul. Ayesha Tanzeem visited and talked with people about the precious oasis.
Video

Video Kenyans Lament Losing Sons to al-Shabab

There is agony, fear and lost hope in the Kenyan town of Isiolo, a key target of a new al-Shabab recruitment drive. VOA's Mohammed Yusuf visits Isiolo to speak with families and at least one man who says he was a recruiter.
Video

Video Scientists Say Plankton More Important Than Previously Thought

Tiny ocean creatures called plankton are mostly thought of as food for whales and other large marine animals, but a four-year global study discovered, among other things, that plankton are a major source of oxygen on our planet. VOA’s George Putic reports.
Video

Video Kenya’s Capital Sees Rise in Shisha Parlors

In Kenya, the smoking of shisha, a type of flavored tobacco, is the latest craze. Patrons are flocking to shisha parlors to smoke and socialize. But the practice can be addictive and harmful, though many dabblers may not realize the dangers, according to a new review. Lenny Ruvaga has more on the story for VOA from Nairobi, Kenya.

VOA Blogs