Genetic identification of Rickettsia sp. strain Atlantic rainforest in an endemic area of a mild spotted fever in Rio Grande do Sul state, Southern Brazil

Rio Grande do Sul state has reported mild spotted fever cases. In addition, the pathogenic Rickettsia sp. strain Atlantic rainforest was genetically identified in the state (Δ). [Display omitted] •Human pathogenic Rickettsia sp. str. Atlantic rainforest was detected in RS.•Amblyomma ovale, the main vector in other states, is also infected in RS.•Dogs can spread these infected ticks to other bordering countries. Rickettsia sp. strain Atlantic rainforest causes a less severe rickettsiosis, with two cases confirmed until now. The tick species Amblyomma ovale is appointed as the main vector of this bacterium. The southern region of Brazil has reported patients with spotted fever who have milder symptoms. In 2013, during an investigation of rickettsiosis cases, an A. ovale tick was found attached to a man in an area where there were two cases. The parasite was processed for molecular analysis and the rickettsial infection was confirmed based on phylogenetic analysis of genes ompA, ompB and geneD (sca4). In the present study the human pathogenic Rickettsia sp. strain Atlantic rainforest was identified in the state of Rio Grande do Sul, Southern Brazil. Since A. ovale, its main vector, is found frequently parasitizing dogs, animals that can cross international borders freely in southern Brazil, this bacteria can bring major concerns in terms of public health.