Identification of canine heartworm and avian malaria vectors in Tennessee

Vector-borne diseases account for 22.8% of emerging infectious diseases and identifying the factors that influence disease transmission are critical especially with a constantly changing habitat (Jones et al. 2008). Two agents transmitted by a variety of mosquitoes include avian malaria (Plasmodium and Haemoproteus) and canine heartworm (Dirofilaria species). The objective of this project is to determine if either pathogen is present in Tennessee field-collected mosquitoes and to identify the species of mosquitoes that harbor each (or both) pathogens. During the summer and fall of 2012 mosquitoes were collected throughout Tennessee using CO₂ traps and gravid traps, and identified to species. Mosquito heads and thoraces underwent DNA extraction and parasite amplification via PCR for Plasmodium and Haemoproteus parasite DNA (cyt b) and for Dirofilaria species DNA (ITS-2 rDNA). All positive PCR amplicons were be bi-directionally sequenced to confirm positivity and to identify the parasite genotype. The confirmation of avian malaria and canine heartworm in the sites and the identification of potential vector populations will begin to unravel the complex relationships that intimately tie together hosts, vectors, and parasites in the transmission of both pathogens. Results provide a significant contribution to the knowledge of the diversity of mosquito parasites present in Tennessee and if positive field populations are present, we expect these results will lead to investigations exploring environmental factors contributing to transmission.