The Bill and Melinda Gates Foundation has awarded a $50.7 million grant to an international research consortium that includes a UC Davis mosquito expert to develop better prevention and treatment strategies for malaria and dengue fever.

Thomas Scott, an expert on the ecology, epidemiology and control of viral diseases that are transmitted by insects, is a key player in the newly funded project, which is directed by the Liverpool School of Tropical Medicine in England. The grant will fund Scott's field studies on dengue fever in Peru.

'Unprecedented opportunity'

In June, Scott received more than $2.2 million from the University of California, Irvine, which is directing a $19.7 million dengue fever research project. That research program is funded by the Foundation for the National Institutes of Health's Grand Challenges in Global Health initiative, launched in 2003 by the Gates Foundation.

"These awards constitute an unprecedented opportunity for my lab and our collaborators from around the world to develop and evaluate novel strategies and products for preventing some of the most important mosquito-borne diseases worldwide," Scott said.

"As a researcher," he added, "it is profoundly meaningful to be able to play a part in reducing death and illness among people in developing countries who suffer the most from these diseases."

An expert on how mosquitoes transmit disease, Scott studies how ecology and environmental factors influence the spread of mosquito-borne viruses. He has done extensive work overseas, spending 15 years in Thailand and six years in Peru.

Mosquito control for malaria and dengue fever

The latest grant is one of three research projects targeting malaria that received a total of $258.3 million this week from the Gates foundation.

The Liverpool-led project in which Scott is participating will be focused on fast-track development of improved insecticides and other mosquito-control methods for malaria and dengue fever. The consortium of academic, commercial and public-health representatives will work to develop safer, more effective and longer-lasting insecticides for mosquito control.

Scott will manage field sites in Peru for testing mosquito-control techniques and products aimed at preventing transmission of dengue fever, which affects millions of people worldwide.

Genetics-based research for dengue fever

In the UC Irvine project funded earlier this year, Scott will select field-test sites in Southeast Asia and Latin America, and oversee the construction and management of large outdoor experimental field cages.

That project is focused on genetics-based strategies for preventing mosquitoes from transmitting the dengue virus.

The researchers will examine how mosquitoes might be genetically modified to reduce the ability of infected mosquitoes to successfully transmit the virus and to reduce or eliminate mosquito populations.

No releases

No genetically modified mosquitoes will be released into the natural environment at any time during the studies.

Dengue fever, which has been known for more than 200 years, is caused by a virus transmitted to people by a mosquito species known as the Aedes aegypti. The disease now is established in more than 100 countries, primarily in Southeast Asia and the Western Pacific, as well as in Africa, the Americas and the Eastern Mediterranean.

An estimated 50 million cases of dengue infection occur annually, according to the World Health Organization, including 100 to 200 cases reported each year in the United States.

Approximately 20,000 people, mostly children, die each year from the disease. Dengue virus causes three diseases: dengue fever, dengue shock syndrome and dengue hemorrhagic fever.