Skeeter Season

Camping season is upon us, and with it came the news of California's first confirmed human case of West Nile virus (WNV).

The San Diego County Health and Human Services Agency (HHSA) announced today that a 76-year-old man contracted WNV, but "he did not acquire the virus locally."

The HHSA, along with other agencies, is urging folks to avoid outdoor activity at dawn and dusk, when mosquitoes are the most active. If you must be outside at that time, they say, use an insect repellent with DEET, Picaridin, oil of lemon eucalyptus or IR3534.

It goes without saying that if you're camping, don't sleep outside unprotected.

Among the other good tips:

• Wear long sleeves and pants when outdoors
• Make sure your windows and doors have tight-fitting screens without holes or tears
• Check your property weekly to eliminate any standing water sources, where mosquitoes can breed.
• Keep your eye on any foreclosed homes in the neighborhood to ensure that swimming pools do not go unattended and containers do not contain water.

Check the California West Nile virus Web site periodically for updates. Lots of good information is on the California Vectorborne Disease Surveillance System, also known as Cal Surv. It includes a history of WNV in California. (WNV first appeared in California in 2002 with the identification of one human case.) Another good site is the Sacramento-Yolo Mosquito and Vector Control District. Michael Parrella, newly selected chair of the UC Davis Department of Entomology, represents Yolo County on the district's Board of Trustees, while Robert Washino, a former chair of the UC Davis Department of Entomology, represents Davis.

Meanwhile, the ground-breaking research (Aug. 18, 2008) of UC Davis chemical ecologists Walter Leal and Zain Syed on why mosquitoes avoid DEET continues to draw attention. It's one of the most downloaded and cited articles from the Proceedings of the National Academy of Sciences (PNAS).

Be careful out there.