Prevalence of \u3ci\u3eRickettsia parkeri\u3c/i\u3e in \u3ci\u3eAmblyomma maculatum\u3c/i\u3e Populations of Southeastern Virginia

Abstract

Amblyomma maculatum has undergone notable expansion northward from its historical region in the Gulf of Mexico, establishing populations along the East Coast into the Carolinas, Virginia, Maryland, New England, and Midwestern states. Amblyomma maculatum is an aggressive human-biting tick and the primary vector for the bacterium Rickettsia parkeri. R. parkeri is the causative agent of Rickettsia parkeri rickettsiosis in humans, a disease similar to but milder than Rocky Mountain Spotted Fever. In 1965, several A. maculatum ticks were found in Virginia, but established populations had yet to emerge. By 2010, established populations of A. maculatum were documented across Southeastern Virginia, showing higher R. parkeri prevalence (\u3e50%) compared to the historic region (R.parkeri on the expansion front raises public health concerns and questions about prevalence patterns between historic and newly established A. maculatum populations. This study analyzes Rickettsia parkeri prevalence among Amblyomma maculatum populations in Southeastern Virginia between 2018 and 2023 to determine if prevalence values remain elevated. Amblyomma maculatum DNA extracts were tested using qPCR for Rickettsia spp. DNA, then specifically for Rickettsia parkeri if the first test showed positive results. Our data will determine if prevalence values changed over time as the ticks became established in the region, which allows for potential connections between higher pathogen persistence and the beginning stages of population expansion