Mosquitoes carrying West Nile virus detected

By Dr. Ananya Mandal, MDSep 12 2011

There is a recent surge in the West Nile-carrying mosquitoes after a relatively dry spell accompanied by warm temperatures last week. The health department monitors about 40 traps across the county two times per week, and last week found four traps in Wheaton alone with infected mosquitoes.

Mosquitoes collected from south San Jose have tested positive for West Nile virus, according to the Santa Clara Count Vector Control District. This finding has prompted the vector control district to plan a mosquito fogging treatment in the south San Jose area on Wednesday night at 11 p.m. The fogging is scheduled to last for several hours. The general area of the fogging is bordered by Hillsdale Avenue on the north, Kenton Lane and Glenmont Drive on the west, Monterey and Dunn avenues on the east, and Foothill Drive on the south.

“West Nile virus continues to be active in mosquitoes in the southwest San Jose area, so it is important to keep the numbers of mosquitoes as low as possible,” district manager Russ Parman said in a statement. “Estimates are that from one to three percent of the mosquitoes in this area are carrying the virus,” Parman said.

In July 6, the first infected mosquito was found in Lemont. The infected mosquitoes are generally most prominent in July and August. But heavy rains in July slowed the spread of the culex and recent cool temperatures are expected to bite into its numbers. After receiving word from the health department of the positive tests for the virus, the Wheaton Mosquito Abatement District sprayed the area to curtail its spread. Thus far, four people in Illinois this year have tested positive for the West Nile virus, with none of those in DuPage.

According to the Illinois Department of Public Health, symptoms of West Nile typically occur between three and 14 days after a bite from an infected mosquitoes. Although mild cases are characterized by a slight fever or a headache, more serious infections can lead to high fever and body ache and, ultimately, death.