TitleMolecular identification of vector-borne organisms in Ehrlichia seropositive Nicaraguan horses and first report of Rickettsia felis infection in the horse.
Publication TypeJournal Article
Year of Publication2019
AuthorsTyrrell, JD, Qurollo, BA, Tornquist, SJ, Schlaich, KG, Kelsey, J, Chandrashekar, R, Breitschwerdt, EB
JournalActa Trop
Date Published2019 Dec
KeywordsAnimals, Cats, Disease Vectors, Ehrlichia, Ehrlichiosis, Horses, Nicaragua, Rickettsia felis, Rickettsia Infections

Certain vector-borne organisms serve as etiological agents of equine disease. After previously identifying a new Ehrlichia species in horses from Mérida, we aimed to determine the infection frequency and screen for a wide range of vector-borne organisms from 93 tick-exposed, Ehrlichia seropositive horses in this region. PCR assays were performed to identify infection by organisms within the following genera: Anaplasma, Babesia, Bartonella, Ehrlichia, Leishmania, Mycoplasma, Neorickettsia, Rickettsia and Theileria. Overall, 90/93 horses (96.8%) were infected with one or more vector-borne organisms. Ninety (96.8%) horses were infected with Theileria equi and 21 (26.8%) with Babesia caballi. Nine (9.7%) horses were infected with the novel Ehrlichia species previously designated H7, reported in horses from Nicaragua and Brazil. Two horses (2.2%) were infected with Rickettsia felis. Anaplasma, Bartonella, Leishmania, Mycoplasma, or Neorickettsia species DNA was not amplified from any horse. Ticks collected from horses infected with vector-borne organisms were identified as Amblyomma cajennense sensu lato and Dermacentor nitens. Horses in Mérida are infected by a range of vector-borne organisms, including B. caballi, T. equi, Ehrlichia species H7, and R. felis. To the authors' knowledge, this constitutes the first report of molecular detection of R. felis in horses.

Alternate JournalActa Trop
PubMed ID31518572