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Newly Patented Virus Could Help Control
Disease-Carrying Mosquitoes By
As surely as swallows return to Capistrano around mid-March each
year, mosquitoes will arrive in force again this spring. Mosquitoes, however,
have become more than just a nuisance. They can transmit diseases such as West
Nile virus (WNV).
One mosquito genus, called Culex,has been found to
transmit WNV and the closely related St. Louis encephalitis (SLE). Now
Agricultural Research Service scientists
have received a patent for a baculovirus--a virus specific to arthropods--that
kills Culex mosquitoes. The patent also includes a method for
transmitting the baculovirus to them. The baculovirus infects only Culex
mosquitoes--not other insects, plants, wildlife or people.
Most people who become infected with WNV or SLE have no
symptoms, or only mild ones, but last year WNV killed 277 people and made more
than 4,000 clinically ill, according to the U.S. Centers for Disease Control and Prevention. The
largest outbreak of SLE in 15 years occurred in 1990. On average, about 128
cases of SLE are reported annually.
Baculoviruses are extremely uncommon in mosquitoes. However,
James J. Becnel, an entomologist with the ARS
Center for Medical, Agricultural and
Veterinary Entomology in Gainesville, Fla., discovered a novel baculovirus
in 1997. Called CuniNPV, it is very stable and persistent and is a promising
candidate to develop into a larvicide.
The baculovirus is activated when it's mixed with magnesium.
When the mixture is added into any body of water where mosquitoes breed, larvae
ingest it. According to Becnel, the virus can kill 85 to 95 percent of
mosquitoes in their natural habitat after two to three days. And the magnesium
won't harm the water.
U.S. Department of Agriculture's chief
scientific research agency, is seeking partners to license the technology and
bring it to the market. Interested parties should contact ARS'
Office of Technology Transfer.