Ticks and tick-borne Rickettsia in El Salvador

From May to November 2013, ticks were collected from wild and domestic hosts that were sampled by convenience in different localities of El Salvador. Among 48 localities, in total 1181 ticks were collected from 200 vertebrate animals, comprising 13 species of wild hosts (amphibian, reptiles, mammals) and five species of domestic mammals, plus four samples from humans and four samples from the environment. Through morphological analysis (corroborated by molecular analyses in a few cases), the following ten tick species were identified: Amblyomma dissimile, Amblyomma mixtum, Amblyomma ovale, Amblyomma cf. parvum, Amblyomma sabanerae, Amblyomma scutatum, Dermacentor dissimilis, Dermacentor nitens, Rhipicephalus microplus, and Rhipicephalus sanguineus sensu lato. Among a sample of 211 tick specimens tested for rickettsial infection by molecular methods, we identified: ‘Candidatus Rickettsia colombianensi’ in 10% of the A. dissimile ticks and 11% of the A. scutatum ticks; Rickettsia amblyommatis in 77% of the A. mixtum ticks, 50% of the A. cf. parvum ticks, 8% of the D. nitens ticks, and 11% of the Amblyomma spp. nymphs; and Rickettsia bellii in 3% of the A. dissimile ticks and 17% of the A. ovale ticks. The tick fauna of El Salvador is currently represented by 12 reported species.