Science abhors a surveillance vacuum: Detection of ticks and tick-borne pathogens in southern New Mexico through passive surveillance.
Authors: Harman Paige R, Mendell Nicole L, Harman Maysee M, Draney Puck A, Boyle Anna T, Gompper Matthew E, Orr Teri J, Bouyer Donald H, Teel Pete D, Hanley Kathryn A
Journal: PloS one
Summary
# Editorial Summary Southern New Mexico has historically lacked systematic tick surveillance, creating a significant blind spot for disease risk assessment across the region. Researchers conducted both active sampling (dragging and CO₂ trapping at 45 sites) and passive surveillance (ticks collected from hunted wildlife, shelter animals, and farm stock) across four southern counties between June 2021 and May 2022, screening all specimens for five major tick-borne pathogens including *Rickettsia rickettsii* and *Ehrlichia* species. Whilst active sampling methods yielded no ticks, passive surveillance recovered 497 specimens representing six tick species (*Rhipicephalus sanguineus*, *Otobius megnini*, *Dermacentor* spp. and others) from both domestic animals and wildlife; notably, *Dermacentor parumapterus* from a black-tailed jackrabbit tested positive for *Rickettsia parkeri* (spotted fever group), and spotted fever rickettsiae were detected in soft tick pools from pallid bats. These findings establish that spotted fever rickettsiosis agents are circulating in southern New Mexico wildlife and tick populations, expanding the documented geographic range of these pathogens and suggesting equine professionals should maintain clinical vigilance for rickettsial disease in endemic areas, particularly given the involvement of *Dermacentor* species, which readily parasitise horses and other livestock in the region.
Read the full abstract on PubMed
Practical Takeaways
- •Equine practitioners in southern New Mexico should be aware that Otobius megnini and Dermacentor species are present in the region and can affect horses; implement tick surveillance and removal protocols
- •Spotted fever rickettsiosis agents (R. parkeri and related rickettsiae) are circulating in wildlife and tick populations in southern New Mexico—consider this differential diagnosis in horses presenting with fever or clinical signs consistent with tick-borne disease
- •Passive surveillance from animals with tick exposure (hunted wildlife, farm animals) is a practical, cost-effective method to monitor regional tick-borne pathogen presence when active sampling yields poor results
Key Findings
- •Passive surveillance identified 497 ticks comprising 7 species across 9 mammal species in southern New Mexico, including domestic horses, dogs, and cats
- •One Dermacentor parumapertus from a black-tailed jackrabbit tested positive for Rickettsia parkeri, an agent of spotted fever rickettsiosis
- •Spotted fever group Rickettsia was detected in 6 of 7 Carios kelleyi pools from pallid bats
- •Otobius megnini was identified on horses along with five other tick species, establishing tick distribution baseline for the region