Featured Research

from universities, journals, and other organizations

Malaria mosquito is disappearing, but it is not necessarily just good news

Date:
August 25, 2011
Source:
University of Copenhagen
Summary:
The incidence of malaria in many African countries south of the Sahara is falling rapidly, shows new research. Scientists have discovered that the mosquito carrying the malaria parasite has practically disappeared from villages without organized mosquito control, and they do not know why. Since the researchers can discount mosquito nets, the question is whether the mosquitoes have succumbed to disease, or communities have been using pesticides, or whether the fall is due to the chaotic new precipitation patterns.

The incidence of malaria in many African countries south of the Sahara is falling rapidly. A Danish-Tanzanian research group has discovered that the mosquito carrying the malaria parasite has practically disappeared from villages without organized mosquito control, and the researchers do not know why. There are several hypotheses but without proper data they cannot say whether malaria is being eradicated or whether it is just resting up before returning with renewed vigour.

"Many of our fellow malaria researchers think that the fall in countries such as Tanzania, Eritrea, Rwanda, Kenya and Zambia shows that all the control programmes are working, particularly the use of mosquito nets," says Associate Professor Dan Meyrowitsch from the Department of Health Services Research at the University of Copenhagen, and continues:

"That just isn't the whole story. For more than ten years we have been collecting and counting the number of mosquitoes in Tanzanian villages. The number in our traps fell from 5300 in 2004 to just 14 in 2009, and these were from villages without mosquito nets."

Dan Meyrowitsch explains that the 99 % fall in the malaria mosquito population during the end of the 1990s seems to be connected to a fall in precipitation. This may be due to global climate changes.

"From 2003 to 2009 the volume of precipitation was more stable, but the rain was more chaotic and fell outside the rainy season. And this may have disturbed the natural cycle of mosquito development," he says.

"Of course it is great that the number of malaria-related fatalities among children has fallen drastically in the last five or six years, but we need to know why!"

Since the researchers can discount mosquito nets, the question is whether the mosquitoes have succumbed to disease, or communities have been using pesticides, or whether the fall is due to the chaotic new precipitation patterns.

"Unless we find the answer we will not be able to predict when the malaria mosquitoes will come back, and that could rapidly prove critical," Dan Meyrowitsch explains.

Many children and adults have not been exposed to malaria in the last five or six years, and so have lost or failed to develop immunity to the parasite.

When the mosquitoes suddenly come back this may mean dramatic malaria epidemics with many fatalities unless the population and the health authorities are ready for them.

The Danish research group comes from three departments at the University of Copenhagen: the Department of International Health, Immunology and Microbiology, the Department of Public Health, and the Department of Veterinary Disease Biology.

The study is funded by the EU, DBL -- Center for Health Research and Development, and The Consultative Research Committee for Development Research, Ministry of Foreign Affairs, Denmark. It was conducted in close cooperation with researchers from the National Institute for Medical Research in Tanzania.

The study: Is the current decline in malaria burden in sub-Saharan Africa due to a decrease in vector population? is published in Malaria Journal.


Story Source:

The above story is based on materials provided by University of Copenhagen. Note: Materials may be edited for content and length.


Journal Reference:

  1. Dan W Meyrowitsch, Erling M Pedersen, Michael Alifrangis, Thomas H Scheike, Mwelecele N Malecela, Stephen M Magesa, Yahya A Derua, Rwehumbiza T Rwegoshora, Edwin Michael, Paul E Simonsen. Is the current decline in malaria burden in sub-Saharan Africa due to a decrease in vector population? Malaria Journal, 2011; 10 (1): 188 DOI: 10.1186/1475-2875-10-188

Cite This Page:

University of Copenhagen. "Malaria mosquito is disappearing, but it is not necessarily just good news." ScienceDaily. ScienceDaily, 25 August 2011. <www.sciencedaily.com/releases/2011/08/110825124258.htm>.
University of Copenhagen. (2011, August 25). Malaria mosquito is disappearing, but it is not necessarily just good news. ScienceDaily. Retrieved August 28, 2014 from www.sciencedaily.com/releases/2011/08/110825124258.htm
University of Copenhagen. "Malaria mosquito is disappearing, but it is not necessarily just good news." ScienceDaily. www.sciencedaily.com/releases/2011/08/110825124258.htm (accessed August 28, 2014).

Share This




More Health & Medicine News

Thursday, August 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Mini Pacemaker Has No Wires

Mini Pacemaker Has No Wires

Ivanhoe (Aug. 27, 2014) Cardiac experts are testing a new experimental device designed to eliminate major surgery and still keep the heart on track. Video provided by Ivanhoe
Powered by NewsLook.com
After Cancer: Rebuilding Breasts With Fat

After Cancer: Rebuilding Breasts With Fat

Ivanhoe (Aug. 27, 2014) More than 269 million women are diagnosed with breast cancer each year. Many of them will need surgery and radiation, but there’s a new simple way to reconstruct tissue using a patient’s own fat. Video provided by Ivanhoe
Powered by NewsLook.com
Blood Clots in Kids

Blood Clots in Kids

Ivanhoe (Aug. 27, 2014) Every year, up to 200,000 Americans die from a blood clot that travels to their lungs. You’ve heard about clots in adults, but new research shows kids can get them too. Video provided by Ivanhoe
Powered by NewsLook.com
Radio Waves Knock out Knee Pain

Radio Waves Knock out Knee Pain

Ivanhoe (Aug. 27, 2014) Doctors have used radio frequency ablation or RFA to reduce neck and back pain for years. But now, that same technique is providing longer-term relief for patients with severe knee pain. Video provided by Ivanhoe
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins