Baseline studies towards the statewide tick and tick-borne pathogen surveillance in New Jersey
Creators: name: Occi, James L.
Publisher: name: No Publisher Supplied
Year: 2022

description: Standardized tick and tick-borne pathogen surveillance requires an understandingof which species may be present and the pathogens they can transmit. We reviewed the scientific literature, government documents and evaluated existing accessioned tick collections (vouchers) in museums and other repositories and determined that the verifiable hard tick fauna of New Jersey (NJ) currently comprises eleven species. Nine are indigenous to North America and two are invasive. For each, we summarize collection details and review known public health and veterinary importance. We also reviewed additional species that may be present in the state or become established in the future but whose presence is not currently confirmed with NJ vouchers. We discuss the importance of vouchers in tick research and surveillance and examine the likelihood and public health consequences of additional hard tick species becoming established in NJ. While the NJ Department of Health has reported between 42 and 144 new cases each year of “spotted fever group rickettsiosis” (SFGR), it is unclear which rickettsial agents (Proteobacteria: Rickettsiaceae: Rickettsia) are infecting NJ residents. We used a combination of conventional and qPCR approaches to screen Dermacentor variabilis Say and Amblyomma americanum L. collected across NJ in 2013-2018. We found zero D. variabilis infected with R. rickettsii, the agent of Rocky Mountain Spotted Fever (RMSF) and, on average, 1.3% infected with presumed non-pathogenic R. montanensis. We also found zero A. americanum infected with R. rickettsii, and 20% infected with R. amblyommatis, a prevalence somewhat lower than in more southern states. Overall, we conclude that it is unlikely that R. rickettsii vectored by D. variabilis is a primary cause of SFGR cases in NJ and discuss our findings in the context of known facts and current limitations. To further examine the composition of NJ’s tick fauna, I established collaborations with bat experts from across NJ and neighboring states. Here I report the detection of larvae of the soft tick Carios kelleyi (Cooley and Kohls), a parasite of bats, for the first time on big brown bats, Eptesicus fuscus (Palisot de Beauvois) (Chiroptera: Vespertilionidae), in NJ. The association of C. kelleyi with bat species that regularly roost in human-made structures, such as attics and barns, and recent isolations from this tick of pathogens capable of infecting humans, companion animals and livestock underscore the need for further studies of these bat ectoparasites. As a result of the collaboration with bat experts, we also recorded for the first time Ixodes scapularis Say (Ixodida: Ixodidae) from big brown bats, Eptesicus fuscus at four locations in rural New York State, USA. All Ixodes infested bats were injured and found on the ground, therefore, parasitism by I. scapularis was likely opportunistic. Nonetheless, the large number of pathogens known to be associated with bats and the frequency with which I. scapularis bites people suggest that this host-tick relationship is of at least potential epidemiological significance. Finally, to assess the risk Carios kelleyi may pose as vectors of pathogens we tested C. kelleyi from New Jersey, New York, Pennsylvania, Ohio, and Vermont for Rickettsia and Borrelia by conventional and real-time PCR. Of 112 C. kelleyi assayed, 35% carried a still undescribed spotted fever Rickettsia, likely the same found in C. kelleyi from Iowa and Kansas, and 5% (exclusively from locations in Pennsylvania) carried the relapsing fever spirochete Borrelia johnsonii determined by a multi-locus sequencing analysis (MLSA), previously found in C. kelleyi in Iowa. Of note, we found a 50% rate of transovarial transmission by testing larvae that hatched from infected females. My overall conclusion is that understanding the prevalence and dynamics of tick-borne pathogens will require collaboration among medical doctors, public health authorities and medical entomologists to follow up presumptive human cases with detailed histories of exposure, species-specific molecular assays, and active surveillance of putative vectors and the pathogens they may carry.