College of Agriculture and Life Sciences
Food Packaging Borrows Space-Age Technology
Learning Something from Nothing
Researcher Develops New Process to Reduce Cost of Ethanol Production
Mentoring Academic Growth in the Community
Mapping Concepts from the Classroom to the Computer
Virginia Tech Assists with Food Safety and Security Efforts
Students Share Nutrition Information
Virginia Tech Expands Aquaculture Research Efforts
Nuts and Seeds May Help Lower Cholesterol
The War on Malaria
Virginia Tech scientists combine entomology, chemistry, genetics, and computer science to fight a deadly disease
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| Areas in the world where malaria is endemic are highlighted in yellow. |
A mosquito bite disturbed a Tanzanian child’s sleep. The mosquito, a female of the genus Anopheles, discovered a way through the net over the girl’s bed and infected her with a mobile, single-celled parasite known as Plasmodium falciparum. After finding its way to her liver, the parasite multiplied and escaped into the bloodstream to devour her red blood cells. Unless properly diagnosed and treated in the weeks that follow, she may develop a life threatening fever and become part of one of the largest public health crises in Sub-Saharan Africa.
According to figures available from the World Health Organization, malaria will infect more than 10 million individuals in Tanzania alone and claim more than 14,000 lives in the East African country—a fraction of the devastation the continent suffers each year.
“As many as 2.5 million people are estimated to die each year from malaria, most of them under the age of five,” says Sally Paulson, an
associate professor of entomology. Although this figure fluctuates each year, the World Malaria Report marked the death toll as high as 3 million in 2005.
Virginia Tech scientists such as Paulson are on the front lines of the most recent battle against malaria.
Jeffrey Bloomquist, a professor of toxicology and pharmacology in the Department of Entomology, hopes a $2.7 million grant will allow his research team to develop an improved insecticide for mosquito nets. These nets, such as the one in the anecdote with the Tanzanian girl, are draped over beds at night, the feeding time for Anopheles mosquitoes. Although proven effective, only one in 20 Africans uses a mosquito net at night according to one study.
The insecticide sprayed on these nets, however, raises a number of concerns. “Our primary issue is making sure it is safe,” Bloomquist says.
Insecticides used for this purpose must be nontoxic to humans and safe for the untrained individuals who apply them to the mosquito nets. Although newer, long-lasting nets exist, the most commonly used nets must be re-impregnated with insecticide every six months. But Bloomquist says Anopheles mosquitoes have evolved a genetic resistance to certain popular insecticides. This means researchers must hurry before the epidemic worsens.
Bloomquist’s project, “Molecular Design of Selective Anticholinesterases for Mosquito Control,” aims to develop an insecticide that targets a specific mosquito species, Anopheles gambiae, the most dangerous mosquito vector for malaria in Africa. Despite its particular focus, this research has tremendous potential for other applications.
“What we are doing can be applicable to other parts of the world, other types of mosquitoes that transmit malaria, and other types of pests that spread diseases,” Bloomquist says.
The researchers are using the biological target—in this case, the enzyme acetylcholinesterase—as a scaffold upon which to assemble its own chemical inhibitor. To build this scaffold, investigators are using “in situ click chemistry.” This approach to drug and insecticide design combines two small inactive molecules into one that disables the function of the protein target. Bloomquist says this is a novel, safe way to create a potent insecticide with species selectivity.
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