2005-7-10
I'm Steve Ember with the VOA Special English Development Report.
Some kinds of fungus are used as a natural treatment in agriculture. Farmers use the organisms to control insects that eat crops. Now, scientists report that these same fungus can also kill mosquitoes that spread malaria. Science magazine published two studies on this subject in June.
In one of the studies, a British team tested a fungus called Beauveria bassiana. They treated surfaces with a liquid that contained the fungus. Then they let mosquitoes rest on the surfaces after a meal of blood. Mosquitoes normally rest for several hours after a blood meal. The scientists were searching for a substance that would infect the mosquitoes during this period.
Matt Thomas of Imperial College London led the study. He says the Beauveria bassiana fungus entered the mosquitoes quickly. It took seven days for the mosquitoes to get sick. After that, they reduced their feeding. Ninety percent of them died within fourteen days.
That was good news. Professor Thomas says mosquitoes normally go one to two weeks between feedings. When they bite, they inject the parasite that causes malaria.
Researchers from the Netherlands and Tanzania did the second study. They treated material with a fungus used to kill locusts. The name of that fungus is Metarhizium anisopliae.
The treated material was hung in several homes in Tanzania. The scientists reported a moderate reduction in the number of malaria-carrying mosquitoes. However, they say the results would still be enough to sharply reduce the spread of malaria.
Malaria is getting more difficult to fight as mosquitoes develop resistance to traditional treatments. Scientists say the fungus could possibly be used instead of chemical poisons to kill mosquitoes. But more research is needed to test how long the fungus can survive in hot environments.
The World Health Organization estimates that malaria kills more than one million people a year, mostly in Africa. Most of the victims are children under the age of five. Pregnant women are also at greater risk from the disease.
The United Nations Millennium Development Goals aim to reduce deaths among children and pregnant women. Malaria control is one way to do that.
This VOA Special English Development Report was written by Jill Moss. Our reports are all on the Web at WWW.testbig.com. I'm Steve Ember.