West Nile virus (WNV) is spread by the bite of infected mosquitos and carries the threat of fatal inflammation of the brain in humans, horses and birds.
Since 2002, the Molecular Science lab has provided testing results for both bird and mosquito disease surveillance.
In 2010 the sentinel mosquito collection program was modified slightly to enhance lab testing during periods of peak mosquito activity.
Participating sites are provided with collection materials and supplies and send Culex mosquitoes to the Molecular Science lab for high throughput RNA extraction and RT-PCR amplification.
All mosquito pools are tested for WNV and selected pools collected from sentinel site traps are also tested for other mosquito-borne viruses, such as Western equine (WEE) and St. Louis encephalitis (SLE) viruses.
By monitoring sentinel sites within the state, infected mosquito populations are detected, types of mosquitos identified and infection rates determined.
Testing results during high and low transmission seasons and from year to year are compared to detect trend changes.
Using a RT-PCR multiplex technique developed by the Molecular Science lab, rapid test results provide a near real-time indication of where WNV-infected mosquitos exist before the first human infection occurs.