Tick-borne relapsing fever (TBRF) spirochetes are likely an overlooked cause of disease in Latin America. In Panama, the pathogens were first reported to cause human disease in the early 1900s. Recent collections of Ornithodoros puertoricensis from human dwellings in Panama prompted our interest to determine whether spirochetes still circulate in the country. Ornithodoros puertoricensis ticks were collected at field sites around the City of Panama. In the laboratory, the ticks were determined to be infected with TBRF spirochetes by transmission to mice, and we report the laboratory isolation and genetic characterization of a species of TBRF spirochete from Panama. Since this was the first isolation of a species of TBRF spirochete from Central America, we propose to designate the bacteria as Borrelia puertoricensis sp. nov. This is consistent with TBRF spirochete species nomenclature from North America that are designated after their tick vector. These findings warrant further investigations to assess the threat B. puertoricensis sp. nov. may impose on human health.

In this paper, we report the mite, Archegozetes magnus immatures and females, in non-parasitic interactions with Bishop's Toad, Rhinella alata (Anura: Bufonidae), and the Buthidae scorpions Tityus jaimei and Tityus festae. The reports in both species of scorpions represent news phoretic interactions. Possible behavior is discussed.

In this work we describe abnormalities in Amblyomma coelebs and Amblyomma cf. oblongoguttatum adults collected from Tapirus bairdii. The observed anomalies in adults corresponded to general (asymmetry of scutum and idiosoma), and local malformation (atrophy and ectromely). This is the first record of morphological anomalies in A. coelebs and also it increases the observations of malformations in ticks from Nicaragua and Central America.

Rickettsia rickettsii is the most virulent agent of the genus Rickettsia that causes one of the most relevant vector-borne diseases in the Americas (RRSF). RRSF manifests with many non-specific acute clinical symptoms complicating its diagnosis and can lead to death if not treated appropriately. RRSF has been reported in Canada, the United States of America, Mexico, Costa Rica, Panama, Colombia, Brazil, and Argentina. In addition to R. rickettsii, mild and severe spotted fever group rickettsioses (SFGR) have been reported in the Americas; however, the true prevalence of these diseases is unknown. In Panama, RRSF have been reported in four of 14 provinces during two outbreak periods: five cases including two fatalities were identified in 1950–1951, and 23 cases including 17 fatalities between 2004 and 2025. This paper presents the clinical characterization of a fatal case of RRSF in Coclé province and a severe case of SFGR in a mountainous area of the Gnäbe Buglé Indigenous Comarca (GBIC). Laboratory confirmation was performed by molecular analysis of tissues obtained from necropsies in the case of RRSF and by immunofluorescence assay (IFA) in the case of SFGR. Furthermore, this paper identifies existing gaps in the initial clinical suspicion and pertinent to SFGR in Panama, which may be applicable to other countries in the region. In the last 21 years, cases have occurred upon contact with ticks in rural areas (13), urban and suburban locations (7), rural woodlands (2), and forests (1). Provinces with more cases are Panamá (7 of 23, 6 died), Coclé (5 of 23, 5 died), Colón (3 of 23, 1 died), Panamá Oeste (1 of 23, 1 died), and GBIC (7 of 23, 4 died), including a cluster of seven cases in 2019. Therefore, Coclé province is considered one of the endemic areas for RRSF in Panama, while the latest cases from the GBIC since 2019 indicate that mountainous areas are an eco-epidemiological scenario to include in the transmission of these diseases. Although this disease has a low prevalence, patients who present symptoms commonly associated with more common diseases such as dengue, other arboviruses, malaria, and leptospirosis, among others, should be included in the diagnostic suspicion. Without diagnostic suspicion and adequate treatment, the patient can die.

This study evaluated the presence of Rickettsia, Anaplasmataceae, Borrelia and Piroplasmida in Amblyomma and Ixodes spp. ticks from wild areas of Panama. Molecular detection of pathogens was performed on the following species of ticks: Amblyomma dissimile, Amblyomma mixtum, Amblyomma naponense, Amblyomma cf. oblongoguttatum, Amblyomma ovale, Amblyomma tapirellum, Haemaphysalis juxtakochi, Ixodes affinis, and Ixodes sp. nymphs. Partial sequences of Ixodes nymphs with the 16S rRNA gene showed low similarity to other Ixodes species. We found evidence of DNA from Rickettsia spp. in A. mixtum (R. amblyommatis), A. dissimile (“Candidatus R. colombianensi”), I. affinis (Rickettsia sp.), and Babesia odocolei in I. affinis. No evidence of DNA from the target microorganisms was detected in A. naponense, A. cf. oblongoguttatum, A. ovale, A. tapirellum, H. juxtakochi, or Ixodes sp. This is the first report of B. odocolei in I. affinis, which represents an additional risk of zoonosis. The detection of Rickettsia spp. corroborates previous findings in Panama. Finally, this study was crucial to determine a putative new species of Ixodes, from two nymph feeding on human.

Rhipicephalus microplus is a globally significant one-host tick that primarily infests cattle. In the Neotropics, this species has been reported on various wild mammals—such as cervids, tapirs, rodents, bats, carnivores and primates—as well as occasionally from humans. Here we report a rare case of R. microplus infestation in a rescued black howler (Alouatta pigra) from Melchor de Mencos, Petén, Guatemala. This tick-host association, documented at the ARCAS Wildlife Rescue Centre, highlights the expanding host range of R. microplus and emphasises the importance of continued surveillance regarding its health consequences in wildlife, zoonotic potential, and host adaptability.