06/24/2005

West Nile Virus-Infected Mosquitoes Found on AU Campus

AUBURN, Ala. — Surveillance teams have detected mosquitoes infected with West Nile virus (WNV) on the Auburn University campus, and while there is no need for the public to be alarmed, AU students and area residents should take precautions to avoid or minimize exposure to mosquitoes, AU entomology professor Gary Mullen said today.

“We began our West Nile campus surveillance program in early May and detected the virus in mosquitoes collected at the (Donald E. Davis) arboretum on June 20,” Mullen said. “This is the earliest we’ve detected the virus in mosquitoes, indicating unusually high active transmission of the virus this early in the year.”

In previous years, it was mid- to late July before infected mosquitoes were detected.

Mullen attributes above-average early spring temperatures and heavy spring rains for the increase in the mosquito population and the earlier occurrence of the virus.

All of the WNV-positive mosquitoes Mullen’s research team has identified have been the Southern house mosquito. Known scientifically as Culex quinqefasciatus, the Southern house mosquito is a common backyard pest that breeds in standing water and bites primarily during the evening and nighttime hours.

Detection of WNV in mosquitoes is not a cause for panic, Mullen said, because, even under epidemic conditions, only 20 to 30 percent of individuals infected with WNV from a mosquito bite develop symptoms, generally in the form of mild flu-like symptoms with a low fever. Only one in 150 cases of infection results in severe neurological disease, characterized by sudden onset of high fever with severe headache, sore neck and generalized muscle aches.

More serious than WNV is another mosquito-transmitted disease, eastern equine encephalitis (EEE), which affects both horses and humans. Already this year, EEE has killed a horse in Mobile County that had not been vaccinated against the disease. All horse owners should be sure their horses’ WNV and EEE vaccinations are up to date.

To protect themselves against mosquito bites, Mullen recommends individual wear insect repellent that contains DEET, picaridin or oil of lemon eucalyptus; wear long sleeves, long pants and socks when outdoors; and avoid outdoor activities in the pre-dawn and early evening hours. Residents should take steps to mosquito-proof their homes and property, such as installing or repairing screens and eliminating standing water, where mosquitoes breed.

This is the fifth year in which Mullen's research group has been involved in the national surveillance program, which is funded by the Centers for Disease Control and Prevention and administered through the Alabama Department of Public Health, to detect and monitor mosquito-borne encephalitis viruses in the U.S. West Nile virus activity was first detected in Alabama in 2001.

West Nile virus is spread by female mosquitoes that contract the virus after feeding on the blood of an infected bird. Ten days to two weeks after a mosquito takes a blood meal from an infected host, the virus can be transmitted to other birds and mammals.

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News from:

Office of Ag Communications & Marketing

Auburn University College of Agriculture
Alabama Agricultural Experiment Station
3 Comer Hall, Auburn University
Auburn, AL 36849
334-844-4877 (PHONE) 334-844-5892 (FAX)

Contact Jamie Creamer, 334-844-2783 or jcreamer@auburn.edu
Contact Gary Mullen, 334-844-2554 or mullegr@auburn.edu

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