COLUMBIA, SC - Thus far in 2007’s mosquito season, there has been a statewide total of 56 lab confirmations of West Nile virus and two of eastern equine encephalitis virus, the S.C. Department of Health and Environmental Control reported recently.

“Of those 56 confirmations for WNV in South Carolina in 2007, four positive cases were in humans, but no West Nile human deaths have occurred so far this year,” said Chris Evans, a Ph.D. entomologist in DHEC’s Bureau of Laboratories. “Other WNV confirmations in the state include 47 mosquito pools, four birds and one horse. Eastern equine encephalitis, or Triple-E, virus was detected in two horses.

“Two human cases of West Nile fever occurred in early to mid-August in Aiken and Newberry Counties,” Evans said. “Two human cases of West Nile neuroinvasive disease occurred in late August in Lexington and Pickens counties.”

According to Evans, 47 WNV-positive mosquito pools were detected. He said a mosquito pool is a group of mosquitoes of the same species collected from the same place on the same dates. The following pools in seven counties were confirmed between July 9 and Oct. 5: Aiken (14), Charleston (11), Clarendon (2), Darlington (14), Dorchester (3), Florence (2), and Richland (1).

He added that three WNV-positive birds were collected in Aiken County from mid-August to early September, along with one York County bird in late July. One Richland County horse had to euthanized in early September after suffering from West Nile symptoms since mid-July, and two horses in Richland and Orangeburg counties were euthanized in August because of a Triple-E virus infection.

“Despite the approaching cooler weather of the fall season, citizens still need to protect themselves from mosquito bites,” Evans said. “The risk for transmission to humans is always greater toward the end of mosquito season.

“Mosquitoes can be active in the fall, even after extended periods of cold weather. In fact, 21 percent of human cases and 49 percent of equine cases from 2002-2006 in South Carolina occurred in October and November.”

Evans also said that people can protect themselves from mosquito bites by:

• Using a repellent containing DEET, picaridin or oil of lemon eucalyptus. Follow the label directions when using any repellent;
• Avoiding the outdoors at dawn or dusk when mosquitoes are most active;
• Wearing long sleeves and pants; and
• Keeping property clear of standing water in which mosquitoes can breed.

The public can help with WNV surveillance by submitting dead crows or blue jays to their local county environmental health office. For guidelines on safely submitting bird samples, visit: http://www.scdhec.gov/westnile, then link to the “Report Dead Birds for WNV Testing” page.

For more information or assistance with mosquito control efforts, contact your city or county’s local mosquito control program. For more information on mosquito-borne disease, visit: http://www.scdhec.gov/westnile. For updated information about recommended mosquito repellants, visit the CDC Web site at: http://www.cdc.gov/ncidod/dvbid/westnile/RepellentUpdates.htm.

Source: State of South Carolina