Epizootiology of dog heartworm, Dirofilaria immits, in Oklahoma

Scope and Method of Study: There were four main objectives of this study. The first was to determine the prevalence of D. immitis in coyotes throughout Oklahoma. The second was to evaluate the relationship between landscape and social factors and the number and species of heartworm positive mosquitoes. The third was to determine which species of mosquitoes trapped are infected with D. immitis in Payne County. The final objective was to determine the importance of Ae. albopictus in D. immitis infections in Payne County.;These objectives were accomplished through a coyote study and a mosquito study. In an effort to learn more about the sylvatic cycle of heartworm in Oklahoma, whole blood and serum samples were collected from 77 coyotes on ranches and in rural areas in seven counties throughout the state from January to March, 2010. Coyote carcasses were donated by the Oklahoma Department of Agriculture, Food, and Forestry USDA Wildlife Services and the Oklahoma Predator Hunters' Association .Blood was collected from harvested coyotes and tested for heartworm using SNAP antigen tests. Mosquitoes were collected using three trapping methods, resting boxes, carbon dioxide traps, and BG sentinel traps, from 16 rural and 16 urban locations in Payne County. They were tested for heartworm using RT-PCR.;Findings and Conclusions: There is a 6.49% prevalence rate of D. immitis in rural Oklahoma coyotes. Urban mosquitoes have significantly higher rates of D. immitis than rural mosquitoes. Aedes albopictus and Psorophora columbiae are important vectors of D. immitis in Payne County, Oklahoma. Urban collected mosquitoes had significantly higher maximum likelihood of infection, 2.59%, than rural collected mosquitoes, 0.97% (P<0.05). Two species, Aedes albopictus and Psorophora columbiae emerged as important vectors if heartworm in Payne County.