Distribution of Spotted Fever Group Rickettsiae in Hard Ticks (Ixodida: Ixodidae) from Panamanian Urban and Rural Environments (2007-2013).

Tick-borne rickettsiosis is an important emerging disease in Panama; to date, there have been 12 confirmed cases, including eight fatalities. To evaluate the distribution of rickettsiae in Panamanian ticks, we collected questing and on-host ticks in urban and rural towns in elevations varying between 0 and 2300 m. A total of 63 sites (13 urban and 50 rural towns) were used to develop models of spatial distributions. We found the following tick species: Rhipicephalus sanguineus s.l. (present in 54 of 63 towns and cities), Amblyomma mixtum (45/63), Dermacentor nitens (40/63), A. ovale (37/63), Rhipicephalus microplus (33/63), A. oblongoguttatum (33/63), Ixodes affinis (3/63), and Ixodes boliviensis (2/63). Rhipicephalus sanguineus s.l. was present in urban and rural towns, and other species were present only in rural towns. DNA was extracted from 408 R. sanguineus s.l., 387 A. mixtum, 103 A. ovale, and 11 A. oblongoguttatum and later tested for rickettsiae genes using PCR. Rickettsia DNA was detected in ticks from 21 of 63 localities. Rickettsia rickettsii was detected in five A. mixtum (1.29%), and Candidatus "Rickettsia amblyommii" was found in 138 A. mixtum (35%), 14 R. sanguineus (3.4%), and one A. ovale (0.9%). These results suggest that much of rural Panama is suitable for the expansion of tick populations and could favor the appearance of new tick-borne rickettsiosis outbreaks.

Current status of Amblyomma ovale (Acari: Ixodidae) in Panama.

The genus Amblyomma is the most diverse and relevant among the Neotropical ticks. In Panama, this genus contains 19 species, including Amblyomma ovale. There is a lack of knowledge of the ecology of A. ovale in Panama, and thus the aim of this work is to report on its geographical distribution and its spectrum of vertebrate hosts. We reviewed data of ticks collected in different areas of Panama from 2007 to 2012 and found parasitism of A. ovale in 625 vertebrates, corresponding to 21 species (2 species of birds and 19 mammal species). A. ovale is present in different environments of Panama, from lowlands to places with 800m altitude, including rural towns, disturbed forests, and wilderness areas.