Detection of <i>Rickettsia</i> spp. in Animals and Ticks in Midwestern Brazil, Where Human Cases of Rickettsiosis Were Reported
Lucianne Cardoso Neves,
Warley Vieira de Freitas Paula,
Luiza Gabriella Ferreira de Paula,
Bianca Barbara Fonseca da Silva,
Sarah Alves Dias,
Brenda Gomes Pereira,
Bruno Sérgio Alves Silva,
Anaiá da Paixão Sevá,
Filipe Dantas-Torres,
Marcelo B. Labruna,
Felipe da Silva Krawczak
Affiliations
Lucianne Cardoso Neves
Veterinary and Animal Science School, Federal University of Goiás, Goiânia 74605-220, Brazil
Warley Vieira de Freitas Paula
Veterinary and Animal Science School, Federal University of Goiás, Goiânia 74605-220, Brazil
Luiza Gabriella Ferreira de Paula
Veterinary and Animal Science School, Federal University of Goiás, Goiânia 74605-220, Brazil
Bianca Barbara Fonseca da Silva
Veterinary and Animal Science School, Federal University of Goiás, Goiânia 74605-220, Brazil
Sarah Alves Dias
Veterinary and Animal Science School, Federal University of Goiás, Goiânia 74605-220, Brazil
Brenda Gomes Pereira
Veterinary and Animal Science School, Federal University of Goiás, Goiânia 74605-220, Brazil
Bruno Sérgio Alves Silva
Directorate of Surveillance in Zoonoses, Superintendence of Health Surveillance, Municipal Health Department, Goiânia 74891-135, Brazil
Anaiá da Paixão Sevá
Department of Agricultural and Environmental Sciences, Santa Cruz State University, Ilhéus 45662-900, Brazil
Filipe Dantas-Torres
Laboratory of Immunoparasitology, Department of Immunology, Aggeu Magalhães Institute, Oswaldo Cruz Foundation (Fiocruz), Recife 50740-465, Brazil
Marcelo B. Labruna
Department of Preventive Veterinary Medicine and Animal Health, Faculty of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo 05508-270, Brazil
Felipe da Silva Krawczak
Veterinary and Animal Science School, Federal University of Goiás, Goiânia 74605-220, Brazil
Brazilian spotted fever (BSF) is the most important tick-borne diseases affecting humans in Brazil. Cases of BSF have recently been reported in the Goiás state, midwestern Brazil. All cases have been confirmed by reference laboratories by seroconversion to Rickettsia rickettsii antigens. Because serological cross-reactions among different rickettsial species that belong to the spotted fever group (SFG) are common, the agent responsible for BSF cases in Goiás remains unknown. From March 2020 to April 2022, ticks and plasma were collected from dogs, horses and capybaras (Hydrochoerus hydrochaeris), and from the vegetation in an area where BSF cases have been reported and two areas under epidemiological surveillance in Goiás. Horses were infested by Amblyomma sculptum, Dermacentor nitens and Rhipicephalus microplus; dogs by Rhipicephalus sanguineus sensu lato (s.l.), Amblyomma ovale and A. sculptum, and capybaras by A. sculptum and Amblyomma dubitatum. Adults of A. sculptum, A. dubitatum, Amblyomma rotundatum and immature stages of A. sculptum and A. dubitatum, and Amblyomma spp. were collected from the vegetation. DNA of Rickettsia that did not belong to the SFG was detected in A. dubitatum, which was identified by DNA sequencing as Rickettsia bellii. Seroreactivity to SFG and Rickettsia bellii antigens was detected in 25.4% (42/165) of dogs, 22.7% (10/44) of horses and 41.2% (7/17) of capybaras, with higher titers for R. bellii in dogs and capybaras. The seropositivity of animals to SFG Rickettsia spp. antigens demonstrates the circulation of SFG rickettsiae in the region. Further research is needed to fully determine the agent responsible for rickettsiosis cases in this area.
