Mosquito pool tests positive for West Nile virus

The Churchill County Mosquito, Vector and Noxious Wed Abatement District has received notification that one of the area’s mosquito pools tested positive for West Nile virus, said District Manager Nancy Upham.

“District staff has been trapping live adult mosquitoes since the beginning of summer and sending these mosquitoes to the state laboratory to determine whether they are positive for any of the encephalitises, such as Western Equine encephalitis, St. Louis encephalitis or West Nile encephalitis,” Upham said.

Upham said the district traps the mosquitoes at night by using carbon dioxide traps, separating the captured mosquitoes by species the next morning and sending them into Reno for diagnostic testing at the Department of Agriculture. She added the separated groups of 50 mosquitoes (or fewer depending on the sample) to be tested are what is being referred to as “mosquito pools” on the radio or in the press.

“This positive pool of mosquitoes is that of Culex tarsalis, which is the typical and most competent vector of West Nile virus.,” Upham said. “This is generally the time of year that we start seeing positive mosquitoes through our testing procedures. This positive pool is an indicator that there are positive mosquitoes potentially throughout the Valley as in other Counties. Where we do have positive mosquitoes, we increase adulticiding efforts or ‘fogging’ in order to break the cycle of large numbers of potentially infected mosquitoes. When possible, we then retest such areas to make sure that we are proactively protecting the Public.

She said this serves as a reminder for residents to take precautions in outdoor activities and especially at dawn and dusk as the female mosquitoes of this species is most active at these times.

Upham said she encourages the public to wear appropriate clothing and/or repellents if people are planning to be outside, and especially at these times. Vaccinations, for horses, are recommended.

“The public is encouraged to call the district if you believe that you may have a mosquito breeding source in or around your home,” she said. Our staff will look at that potential for you. At this point, common breeding sites around the home are over-watered lawns, over-watered potted plants, kid pools for dogs, water troughs for livestock and even storm drains along your roadside.”

“Our staff has been monitoring such storm drains as well as drains at the lower end of fields as common practice every year. We have been working throughout the valley and will continue to do so throughout the summer and fall.”

If you have any questions regarding mosquito abatement measures, call the District office (423-2828) and leave a message with your address and telephone number. The staff is mostly out in the field all day and will call back.