Amblyomma americanum distribution, seasonality, and pathogen prevalence at Ames Plantation

Abstract:

The status of tick-borne disease in the southeastern United States is uncertain due to emerging/resurging pathogens and modifications to landscape. The objective of this study is to identify distribution, seasonality, and pathogen prevalence of A. americanum in western Tennessee. Ticks were collected from April to October 2012, using vegetation drags for passive collections and CO₂ traps for active collections. Identified adult A. americanum were screened for Ehrlichia spp., Rickettsia spp., and Borrelia burgdorferi to determine pathogen prevalence, and positive samples were sequenced to confirm positivity. Using ArcGIS A. americanum collections and positive samples were displayed with environmental variables for future correlations between habitat type and A. americanum populations. Preliminary sampling indicates that A. americanum is the most abundant tick species and populations are positively correlated with deciduous forests incorporating good drainage, sandy or medium texture soil, moderate ground temperature, and high relatively humidity. We expect the abundance of A. americanum to influence the diversity and density of its distribution and pathogen prevalence compared to other tick species collected in western Tennessee. Additional results will be presented.

Key words: Amblyomma americanum, Erhlichia spp., Rickettsia spp., and Borrelia burgdorferi