Rickettsia amblyommatis-infected Amblyomma coelebs parasitizing a human traveler in Rio Grande do Sul, southern Brazil, after returning from the Amazon.

With increased national and international transportation, humans as well as domestic and wild animals are able to get from one end to the other within hours, accidently carrying transboundary vectors and pathogens. We report here, the introduction of Amblyomma coelebs in Rio Grande do Sul, the southernmost state of Brazil, via a man travelling to the Carajás National Forest in the state of Pará (2661 km away). Upon return to his residence in Porto Alegre, RS, he realized that he was parasitized by one tick. The tick was identified as a nymph of Amblyomma sp., placed in a Biological Oxygen Demand incubator, and after ecdysis was identified as a male of Amblyomma coelebs. The tick's DNA was screened for Rickettsia spp., where Rickettsia amblyommatis DNA was detected. The parasitized man was seropositive to spotted fever group rickettsiae, by immunofluorescence assay, in a single serum sample collected 45 days after the tick-bite. Amblyomma coelebs is found in some Brazilian states, but Parana is the southernmost state in Brazil where it occurs. This species has already been reported to carry some species of Rickettsia, including species of the spotted fever group. It may risk public health if established in Rio Grande do Sul, with the introduction of tick and pathogenic rickettsias.