Collaborating With Community Scientists Across Arkansas to Update Tick Distributions and Pathogen Prevalence of Spotted Fever Group Rickettsia and Ehrlichia

Abstract

Tick-borne diseases (TBD) in humans have dramatically increased over recent years and although the bulk of cases are attributable to Lyme Disease in the Northeastern US, TBDs like spotted fever rickettsiosis and ehrlichiosis heavily impact other parts of the country, namely the mid-south. Understanding tick and pathogen distributions and prevalence traditionally requires active surveillance, which quickly becomes logistically and financially unrealistic as the geographic area of focus increases. We report on a community science effort to survey ticks across Arkansas to obtain updated data on tick distributions and prevalence of human tick-borne disease-causing pathogens in the most commonly encountered ticks. During a 20-mo period, Arkansans submitted 9,002 ticks from 71 of the 75 counties in the state. Amblyomma americanum was the most common tick species received, accounting for 76% of total tick submissions. Nearly 6,000 samples were screened for spotted fever group Rickettsia (SFGR) and Ehrlichia, resulting in general prevalence rates of 37.4 and 5.1%, respectively. In addition, 145 ticks (2.5%) were infected with both SFGR and Ehrlichia. Arkansas Department of Health reported 2,281 spotted fever and 380 ehrlichiosis cases during the same period as our tick collections. Since known SFGR vectors Dermacentor variabilis and Amblyomma maculatum were not the most common ticks submitted, nor did they have the highest prevalence rates of SFGR, it appears that other tick species play the primary role in infecting humans with SFGR. Our investigation demonstrated the utility of community science to efficiently and economically survey ticks and identify vector-borne disease risk in Arkansas.

Tick (Acarina: Ixodidae) Species and Life Stages Collected from Arkansas Wild Pigs

“…Results from this study support data from Dowling et al (2021) that A. americanum is the most abundant ixodid tick species in Arkansas. During a 20-mo period, Arkansas residents from across the state sent in 9,002 ticks collected from humans, cats, dogs, horses, goats, raccoons, rabbits, potbelly pigs, cattle, deer, and feral hogs (Dowling et al 2021). Amblyomma americanum was the most common species found in this survey, accounting for 76% of the ticks sent in (Dowling et al 2021).…”

“…Amblyomma americanum was the most common tick species found in this study (Table 2). This was expected because A. americanum is the most abundant species in Arkansas, exhibits little host specificity, and has been documented on wild pigs in Arkansas and other states (Tugwell & Lancaster 1962;Smith et al 1982;Cohen et al 2010;Schuster 2011;Sanders et al 2013;Dowling et al 2021). Amblyomma americanum was collected from Feb 2019 to Jan 2020 (Table 3).…”

All for One Health and One Health for All: Considerations for Successful Citizen Science Projects Conducting Vector Surveillance from Animal Hosts

“…Another method of collection kit distribution is sending or dropping off kits at designated locations where specific groups frequent, such as a veterinary clinic or hospital, livestock market location, or an Extension office [ 24 ]. While not a location they may frequent, those who work with companion animals can also pick up and drop off kits at the research institution housing the project.…”

“…Working with this stakeholder group, researchers utilized a variety of methods to passively sample ectoparasites, including using collection kits that were available through different avenues (available for pickup/drop off at researcher/Extension offices or sent to citizen scientists), submitting specimens to a research laboratory or institution, and submitting photos to a website or mobile device application. Unlike those who had occupations working with animals, only two studies that targeted animal owners utilized pre-made collection kits [ 15 , 24 ]. Instead, the majority of studies that involved animal owners advertised their studies online using a dedicated project website and/or outreach to recruit citizen scientists [ 18 , 37 , 46 , 47 , 48 , 49 , 50 , 51 ].…”

“…While we included farmers in the Section 3 , we did not find studies that specifically targeted this group for any ectoparasite collection. That is, studies were broadly requesting specimen collections from the general public, which includes farmers and their animals [ 15 , 24 ]. This was unexpected considering that farmers have previously provided large-scale spatial and temporal data in studies involving agricultural practices and farmland management [ 118 , 119 , 120 ], so farmers seem able and willing to collaborate with researchers.…”