D3219: Surveilling potential and emerging tick-borne threats along the US-Mexico border

Diagnosis and prevention of tick-borne pathogens can be improved by robust tick surveillance, yet surveillance efforts in the U.S. are highly uneven and leave large gaps, particularly at the U.S.-Mexico border. Our study aims to provide updated information on distributions of ticks and tick-borne pathogens in southern New Mexico as part of a larger effort to close this surveillance gap. We conducted active tick sampling using dragging and CO₂ trapping techniques at 45 sites in Hidalgo, Doña Ana, Otero, Eddy, and Lea counties at various temporal and spatial intervals between June 2021 and May 2022; however, these efforts yielded no ticks. We also conducted opportunistic, passive sampling in 2021 through tick collections from animals harvested by hunters or researchers and live animals housed in animal hospitals, shelters, and farms, yielding 499 ticks comprising Carios kelleyi from Antrozous pallidus, Rhipicephalus spp. from Canis familiaris, Odocoileus hemionus, and Cervus canadensis nelsoni, Otobius megnini from Canis familiaris, Felis catus, Equus caballus, and Odocoileus virginianus, and Dermacentor parumapertus from Lepus californicus, Odocoileus hemionus, Ursus americanus amblyceps and Cervus canadensis nelsoni. To date, 130 ticks have been molecularly screened for a panel of bacterial pathogens in the genus Rickettsia and Ehrlichia, of which one pool of D. parumapertus from a black-tailed jackrabbit (L. californicus) in Luna County, tested positive for a pathogen, Rickettsia parkeri, an agent of spotted fever rickettsiosis. Our findings inform the public, medical, and veterinary communities of the potential tick-borne pathogens present in southern New Mexico.