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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Ecology of a tick-borne spotted fever in southern Brazil

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Author(s):
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Krawczak, Felipe S. ; Binder, Lina C. ; Oliveira, Caroline S. ; Costa, Francisco B. ; Moraes-Filho, Jonas ; Martins, Thiago F. ; Sponchiado, Jonas ; Melo, Geruza L. ; Gregori, Fabio ; Polo, Gina ; Oliveira, Stefan V. ; Labruna, Marcelo B.
Total Authors: 12
Document type: Journal article
Source: Experimental and Applied Acarology; v. 70, n. 2, p. 219-229, OCT 2016.
Web of Science Citations: 8
Abstract

Rio Grande do Sul is the southernmost state of Brazil, bordering Uruguay. Clinical cases of spotted fever group (SFG) rickettsiosis were recently reported in Rio Grande do Sul. None of these cases was lethal, and all were confirmed by seroconversion to R. rickettsii antigens. Because serological cross-reactions are well known to occur between different SFG agents, the SFG agent responsible for the clinical cases remains unknown in Rio Grande do Sul, where no rickettsial agent is known to infect ticks. During 2013-2014, ticks and blood sera samples were collected from domestic dogs and wild small mammals, and from the vegetation in a SFG-endemic area of Rio Grande do Sul. Dogs were infested by Amblyomma ovale adult ticks, whereas small mammals were infested by immature stages of A. ovale, Ixodes loricatus, and adults of I. loricatus. Ticks collected on vegetation were adults of A. ovale, and immature stages of A. ovale, Amblyomma dubitatum, and Amblyomma longirostre. Three Rickettsia species were detected: Rickettsia bellii in I. loricatus, Rickettsia amblyommii in A. longirostre, and a Rickettsia parkeri-like agent (Rickettsia sp. strain Atlantic rainforest) in A. ovale. Seroreactivity to SFG antigens were detected in 19.7 % (27/137) canine and 37.5 % (15/40) small mammal sera, with highest titers to R. parkeri. Results indicate that the R. parkeri-like agent, strain Atlantic rainforest, is circulating between A. ovale ticks, dogs and small mammals in the study area, suggesting that this SFG pathogen could be one of the etiological agents of SFG clinical cases in Rio Grande do Sul. (AU)

FAPESP's process: 12/21915-4 - Survey for rickettsial infection of the spotted fever group in dogs, small mammals and ticks in endemic and non-endemic areas of the Pampa and Atlantic forest biomes in the state of Rio Grande do Sul.
Grantee:Felipe da Silva Krawczak
Support Opportunities: Scholarships in Brazil - Doctorate