Friday, December 17, 2010

Sterilizing male malarial mosquitoes

A scientific facility in Vienna is attempting to sterilize male mosquitoes to help lessen malaria. The male's sole purpose in life is to reproduce, so the hope is sterilizing them will reduce the population of malarial mosquitoes.

From the Inter Press Service, writer Timothy Spence explains the process to us.

Entomologists and other researchers at the International Atomic Energy Agency (IAEA) are testing whether sterilised insect technique (SIT) can be used to reduce populations of malarial mosquitoes. Experiments are taking place at the agency’s laboratory facilities in eastern Austria, and researchers emphasise that their work is at an early stage.

Though the IAEA is better known for inspecting nuclear sites and non- proliferation treaties, its researchers are engaged in other activities, such as using atomic technologies and precision measuring devices to develop more efficient crop irrigation techniques, improve medical diagnoses and calibrate scientific equipment. They also train scientists from developing countries.

The focus of the malaria research so far has been on Anopheles arabiensis, a mosquito species that thrives in the Nile River basin in Sudan. Sudan’s government requested IAEA assistance in reducing the prevalence of malaria in the region. More than 500,000 malaria cases are reported every year in the country of 43 million, and malaria accounts for some 32,000 deaths annually, according to the Global Fund, the public-private partnership that channels money into combating malaria, AIDS and tuberculosis.

Researchers at the Austrian lab have established a colony of the Anopheles mosquitoes that are the target of SIT research. Experiments involve a painstaking process restricted by the relatively short lifespan of the insects - - less than a month -- and the handful of hours when the sterilisation procedure is optimal.

In the lab, the mosquitoes are separated by sex. The males get a blast of up to 100 Gray in a cobalt irradiator, a lethal radiation dose for a human. The sterilised males are then placed in a mesh-covered box where males and females mix in a frenzied mating ritual.

"This is like a crowded discotheque," said Jérémie Gilles, a French entomologist and one of eight researchers working on the project.

SIT has been used successfully to suppress other pests -- often invasive species -- by flooding nature with insects that cannot reproduce.

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