The wild life of ticks: Using passive surveillance to determine the distribution and wildlife host range of ticks and the exotic Haemaphysalis longicornis, 2010–2021

Abstract

Background We conducted a large-scale, passive regional survey of ticks associated with wildlife of the eastern United States. Our primary goals were to better assess the current geographical distribution of exotic Haemaphysalis longicornis and to identify potential wild mammalian and avian host species. However, this large-scale survey also provided valuable information regarding the distribution and host associations for many other important tick species that utilize wildlife as hosts. Methods Ticks were opportunistically collected by cooperating state and federal wildlife agencies. All ticks were placed in the supplied vials and host information was recorded, including host species, age, sex, examination date, location (at least county and state), and estimated tick burden. All ticks were identified to species using morphology, and suspect H. longicornis were confirmed through molecular techniques. Results In total, 1940 hosts were examined from across 369 counties from 23 states in the eastern USA. From these submissions, 20,626 ticks were collected and identified belonging to 11 different species. Our passive surveillance efforts detected exotic H. longicornis from nine host species from eight states. Notably, some of the earliest detections of H. longicornis in the USA were collected from wildlife through this passive surveillance network. In addition, numerous new county reports were generated for Amblyomma americanum, Amblyomma maculatum, Dermacentor albipictus, Dermacentor variabilis, and Ixodes scapularis. Conclusions This study provided data on ticks collected from animals from 23 different states in the eastern USA between 2010 and 2021, with the primary goal of better characterizing the distribution and host associations of the exotic tick H. longicornis; however, new distribution data on tick species of veterinary or medical importance were also obtained. Collectively, our passive surveillance has detected numerous new county reports for H. longicornis as well as I. scapularis. Our study utilizing passive wildlife surveillance for ticks across the eastern USA is an effective method for surveying a diversity of wildlife host species, allowing us to better collect data on current tick distributions relevant to human and animal health.

Spatial and risk factor analyses of vector-borne pathogens among shelter dogs in the Eastern United States

“…Continued studies on the distribution of VBP are warranted, as changes in the distribution and density of vectors and their associated pathogens have been noted in recent years, which may be related to several factors such as climate or habitat changes [5,8,[20][21][22][23]36]. Additionally, novel vectors (e.g., Asian longhorned tick, Haemaphysalis longicornis) have been introduced into the United States, and this tick may alter the native pathogen transmission dynamics [37][38][39][40][41].…”

Phylogeography of the blacklegged tick (Ixodes scapularis) throughout the USA identifies candidate loci for differences in vectorial capacity

“…Collaborators shipped previously identified samples from past collection seasons (2010–2020) stored in 70% or 85% ethanol to the University of Georgia (UGA) Environmental Health Science (EHS) DNA laboratory for sequencing. These tick samples were collected from either drag sampling or animal hosts, with hunter‐harvested white‐tailed deer ( Odocoileus virginianus ) transported to check stations or local meat processors being the most common type of animal host collection (Thompson et al, 2022). For the second collection strategy, we implemented a community science approach to cover areas that did not have large research collection efforts established.…”

Human risk to tick encounters in the southeastern United States estimated with spatial distribution modeling

“…Prior to the range expansion of A. americanum, D. variabilis was the most commonly encountered tick in southeastern US [14,[80][81][82]. Areas where D. variabilis was least likely to be encountered included more southern areas of the study region such as the Southern Coastal Plain and Southeastern Plains, typically characterized as subtropical, low-elevation, sandy, and PLOS NEGLECTED TROPICAL DISEASES areas with marshlands in Florida [71].…”