Evaluating Surveillance Methods for Arboviral Vectors of La Crosse Virus and West Nile Virus of Southern Appalachia.

Abstract

To monitor mosquito-borne diseases, public health departments conduct mosquito and pathogen surveillance. Our objective was to evaluate mosquito monitoring methods for collecting La Crosse virus (LACV) and West Nile virus (WNV) vectors (Aedes and Culex mosquitoes, respectively) in southern Appalachia. Centers for Disease Control and Prevention (CDC) light traps baited with carbon dioxide (CO(2)), CDC light traps baited with CO(2) and BG lure, BG-Sentinel traps baited with CO(2), gravid traps baited with oak (Quercus)-water infusion, and resting traps were compared in eastern Tennessee in 2013. Traps operated at 8 different urban sites throughout Knox County were randomly assigned to and rotated among 6 plots within each site. Results were specific for each vector; the BG-Sentinel trap was the best method for Aedes triseriatus, the CDC trap baited with CO(2) and BG lure was the best method for Ae. albopictus, and the gravid trap was the best method for Ae. japonicus. Culex erraticus collections varied by week and trapping method, indicating no single method was best, but the questing traps collected more mosquitoes. There was no significant trapping difference for Cx. pipiens complex in this region using the methods tested. The results suggest using a combination of trapping methods when sampling for LACV and/or WNV mosquito vectors in southern Appalachia. Effective trapping methods are necessary to enable accurate surveillance, improve control methods, enhance understanding of dispersal, and use for early detection of vectors and pathogens.