Surveillance & Testing
Many areas of Bannock County may be affected by one or more mosquito problems. The Bannock County Mosquito Abatement District (BCMAD) focuses abatement efforts towards reducing the populations of Culex species of mosquitoes, which are the primary disease vectors for West Nile Virus, and reducing the populations of other nuisance species to maintain a quality of life for the residents of Bannock County.
- Factors that govern monitoring are service requests, air temperature, water temperature, humidity, rainfall, permanent water levels, irrigation water levels and retention catch basin water levels.
- Evaluation of control measure efficacy and effectiveness. This becomes important after adulticide applications and emergency aerial applications.
- Continuous monitoring of population dynamics. This is accomplished by the use of Center for Disease Control (CDC) CO2 baited traps in strategic locations.
- Mosquitoes are attracted to the light of the trap and Carbon dioxide from the dry ice inside.
West Nile Virus Surveillance & Testing
West Nile Virus surveillance is done in all BCMAD sectors each week starting in April or, as weather permits, sooner. Eight to eleven CDC CO2 baited light traps are deployed in any given sector, per night. Most of the traps are at permanent sites while the others are moved on a continuous basis. All sites and applications are marked by GPS coordinates.
Vector species (Culex species) are pooled into testing groups and tested for West Nile Virus using the R.A.M.P. (Rapid Analytical Measuring Platform) system.
Some of the trap sites are earmarked as canopy sites, meaning that the traps are suspended into trees 25 to 30 feet for surveillance of actively feeding Culex tarsalis or Culex pipiens. Traps are deployed before sun down and retrieved the next morning.
Test results are known within 24 to 48 hours, so mosquito management decisions can be implemented in a timely manner. Positive virus pools are communicated with Idaho Department of Health and Welfare and with County officials so appropriate press release information can be made. Positive pools are further tested by the Idaho Bureau of Laboratories for Western Equine Encephalitis or St. Louis Encephalitis.