West Nile Virus conference is Feb. 24 in Pierre A South Dakota West Nile Virus/Mosquito Control Conference is set for Feb. 24, 2005, in the Ramkota Inn in Pierre.
State epidemiologist Lon Kightlinger of the South Dakota Health Department said the conference is intended for city, county and tribal leaders and for the key personnel who will be carrying out mosquito control programs in 2005.
This will serve as a re-certification training for commercial applicators in Category 9 (Public Health), according to Steve Spitler, an ag program specialist with the South Dakota Department of Agriculture.
Before the West Nile Virus outbreak, only 23 individuals in South Dakota were certified to spray for mosquitoes, Spitler said. In 2004 the number of commercial applicators in the state licensed to spray for mosquitoes is 519.
One key reason West Nile Virus affected relatively few humans in South Dakota in 2004 compared to 2003, Kightlinger said, is that 64 percent of South Dakotans now live in towns that have had mosquito control programs.
"Based on 2000 census data, I calculate that 484,663 people in South Dakota are living in cities and towns with mosquito control out of our 2000 census population of 755,884 residents," Kightlinger said.
Partly as a result of those mosquito control programs, South Dakota had only 51 cases of West Nile Virus illness in humans in 2004 compared to 1,039 in 2003.
Kightlinger added that several other factors also played a role in keeping West Nile Virus numbers down. A massive educational campaign by SDSU Extension and the state Health Department were successful in getting people to use mosquito repellents such as those containing DEET, to wear long-sleeved clothing, and to eliminate mosquito breeding areas.
In addition the cooler summer in 2004 helped keep mosquito numbers down and probably also helped encourage people to wear pants and long-sleeved shirts. Finally, Kightlinger said, natural selection is making the bird population less susceptible to West Nile Virus, which means there simply may not be as much of the virus present in birds for mosquitoes to spread to humans.
SDSU Extension Entomologist Mike Catangui added that an extensive mosquito collection network coordinated by SDSU research parasitologist Mike Hildreth and SDSU Extension pesticide education coordinator Jim Wilson played a key role in monitoring for West Nile Virus. Based partly on that surveillance work, Catangui issued science-based thresholds recommending when communities should spray for mosquitoes.
"The extensive mosquito collection network enabled us to know what and when vectors were biting, and also when the first positive mosquitoes were found," Catangui said. "The traps actually indicated that the main vector, Culex tarsalis or the encephalitis mosquito, was actually very abundant at most sites. A lot of positive mosquitoes were flying around and yet there were very few disease cases in most areas."
The Feb. 24 conference runs from 9:30 a.m. to 4 p.m. Main speaker Nolan Newton, chief of public health pest management for the North Carolina Department of Environment and Natural Resources, will discuss options for creating and maintaining an active mosquito program.
Experts from SDSU, the South Dakota Health Department, the South Dakota Department of Agriculture, and South Dakota cities and tribes will also speak. Their topics include South Dakota updates on West Nile Virus in humans, horses, and game birds, larvaciding, surveillance, regulatory requirements, and calibrating and maintaining applicator equipment.
SDSU Cooperative Extension, the South Dakota Department of Health, and the South Dakota Department of Agriculture are organizing the conference jointly.