West Nile Virus Detected in Laramie

By: John Tann

West Nile virus (WNv) has been documented in a mosquito sample collected southwest of Laramie. The positive sample was isolated in mosquitoes
collected from a surveillance trap monitored by City of Laramie Mosquito Control. The adult mosquito trap was located approximately six miles southwest of city limits. The
samples were determined to be positive for WNv using the City’s Rapid Analyte Measurement Platform (RAMP).

The rating of the Risk of West Nile virus infection continues to be rated at LEVEL 1 (LOW RISK) based on the Centers for Disease Control (CDC) guidelines for a phased response
to WNv surveillance data. Currently, virus activity is categorized as “limited to sporadic activity in local mosquitoes and birds.” City of Laramie Mosquito Technicians have tested
a total of twenty-two (22) samples of Culex tarsalis mosquitoes in 2019 with two (2) samples being positive. Culex tarsalis is the known vector of WNv in the region. No avian,
equine, or human cases have been reported at this time in Albany County. Wyoming Department of Health has reported one human noninvasive locally acquired case in
Campbell County.

Current surveillance locally shows low to moderate numbers of vector mosquitoes being collected at trap locations adjacent to the Big Laramie River and in rural locations. Residential surveillance sites within the city limits report low vector numbers. Overall, nuisance mosquito numbers have been decreasing and vector mosquito numbers have been slowly increasing.

Mosquito control will continue to fog residential neighborhoods where both vector and nuisance mosquitos are being found in adult mosquito surveillance traps. Mosquito
Control is also currently performing targeted fogging operations to control vector mosquitoes in areas of higher vector densities and areas where citizens often recreate in the evening hours. Targeted areas include parks and recreation areas, golf courses, and the Laramie River Greenbelt Trail. All “No Spray” zones will continue to be honored at this
time.

Citizens are reminded that WNv can infect people of all ages, but the elderly may be at the greatest risk for a serious infection. Locally, the mosquitoes that transmit WNv are most active after dusk, and citizens should limit activities in areas with high mosquito populations during this time. Repairing screens, especially in sleeping rooms, and using
personal protection, such as proper clothing, and insect repellent containing DEET can also reduce the risk. Further Wyoming WNv information can be found online at the
http://www.badskeeter.org or the Centers for Disease Control website:
http://www.cdc.gov/westnile/index.html

Hotline information regarding chemical applications on City owned properties will beupdated daily at 4:00 p.m. Call 721-5056 or click on the Mosquito and Chemical
Application hotline tab on the City of Laramie home page (https://www.cityoflaramie.org/485/Mosquito-Chemical-Application-Hotline). For further information contact Tyler Shevling, Mosquito Control Crew Supervisor at 721-5258; tshevling@cityoflaramie.org or Todd Feezer, Assistant City Manager at 721-5226; tfeezer@cityoflaramie.org.