First report of Amblyomma sculptum (Amblyomma cajennense complex) in a Brazilian state classified as a silent area for human rickettsiosis

Background and Aim: Studies on ticks of public health concern in equine husbandry are scarce in the Northeastern region of Brazil. This study aimed to investigate the presence of ticks on horses in the State of Alagoas, which is classified as a silent area for human rickettsiosis. Materials and Methods: Ticks infesting horses were collected using anatomical tweezers or a commercial hook and kept in ethanol-labeled tubes for taxonomic identification. Results: A total of 2,238 ticks were found. Ticks were identified as 2,215 (98.89%, 95% CI: 98.41–99.28) Dermacentor nitens, 19 (0.98%, 95% CI: 0.05–1.38) Amblyomma sculptum, and 4 (0.18%; 95% CI: 0.007–0.46) Rhipicephalus microplus. Conclusion: This is the first study to report A. sculptum and D. nitens in the State of Alagoas. The presence of A. sculptum should draw the attention of public health managers once Alagoas State is considered a silent area for rickettsial diseases, which means the absence of local surveillance programs for these pathogens.