Surveillance & Testing
Many areas of Canyon County may be affected by one or more mosquito problems. The Canyon County Mosquito Abatement District focuses abatement efforts towards reducing the populations of Culex species of mosquitoes, which are the primary disease vectors for West Nile Virus.
Mosquitoes are attracted to the trap by light, heat, and CO2
Surveillance Methods
- Continuous monitoring of population dynamics. This is accomplished by the use of of CDC Co2 baited traps in strategic locations.
- 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.
Arbovirus (West Nile Virus) Surveillance and Testing
Mosquitoes are frozen and identified.
This is by far the most important function of mosquito monitoring and surveillance. Past history has shown that early detection is important in preventing the spread of an arbovirus disease such as West Nile Virus.
West Nile Virus surveillance is done in all CCMAD sectors each week starting in May or as weather permits sooner. Eight to ten 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 are GPS coordinate-marked.
Vector species (Culex sp.) 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 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.
2011 Surveillance/Disease Trapping & Testing Sites
