West Nile Virus has been detected in multiple samples.  The Mosquito Control District (the District) routinely sets traps for the purpose of both monitoring mosquito populations and to test certain mosquito species for the presence of mosquito borne illnesses.  The District tests for West Nile Virus (WNV), St. Louis Encephalitis (SLE), and Western Equine Encephalitis (WEE).  The District has two species known to be potential carriers of these three diseases; Culex pipiens and Culex tarsalis.  The testing of captured mosquitoes consists of pools (collections of same species mosquitoes from a single trap source in numbers of 20-50 per pool) being analyzed with in house PCR (polymerase chain reaction) testing. 

To see the areas where mosquito disease has been detected, please click the following link:  Mosquito Borne Illness Map

The District applies appropriate mitigation strategies to reduce the number of mosquitoes in an attempt to interrupt the disease cycle, but since West Nile Virus is primarily a mosquito-bird virus, once introduced into an area, it is extremely difficult to interrupt the cycle.  The District recommends that you consider an EPA registered active ingredient in your repellent, avoid mosquito areas at dusk and dawn (when activity levels can be higher), dump out any standing water at least once per week, and to call us should you have any questions or would like us to inspect a water site for the presence of mosquito larvae.

You can learn more about mosquito borne illness and what the District is doing to monitor for disease by going to our Disease Page.