Study of infection by ricketsiae of the spoted fever group in humans and ticks in an urban park located in the City of Londrina, State of Paraná, Brazil

Roberta Santos Toledo, Katia Tamekuni, Mauro de Freitas Silva Filho, Valeska Bender Haydu, Richard Campos Pacheco, Marcelo Bahia Labruna, John Stephen Dumler, Odilon Vidoto

Research output: Contribution to journalArticlepeer-review

3 Scopus citations

Abstract

Introduction: Spoted fevers are emerging zoonoses caused by Ricketsia species in the spoted fever group (SFG). Ricketsia ricketsii is the main etiologic agent of Brazilian spoted fever (BSF) and it is transmited by Amblyomma spp. ticks. Methods: Te study aimed to investigate SFG Ricketsiae in the Arthur Tomas Municipal Park in Londrina, PR, by collecting free-living ticks and ticks from capybaras and blood samples from personnel working in these areas. Samples from A. dubitatum and A. cajennense were submited for PCR in pools to analyze the Ricketsia spp. gltA (citrate synthase gene). Results: All the pools analyzed were negative. Human sera were tested by indirect immunofuorescence assay with R. ricketsii and R. parkeri as antigens. Among the 34 sera analyzed, seven (20.6%) were reactive for R. ricketsii: four of these had endpoint titers equal to 64, 2 titers were 128 and 1 titer was 256. None of the samples were reactive for R. parkeri. An epidemiological questionnaire was applied to the park staf, but no statistically signifcant associations were identifed. Conclusions: Te serological studies suggest the presence of Ricketsiae related to SFG that could be infecting the human population studied; however, analysis of the ticks collected was unable to determine which species may be involved in transmission to humans.

Original languageEnglish (US)
Pages (from-to)313-317
Number of pages5
JournalRevista da Sociedade Brasileira de Medicina Tropical
Volume44
Issue number3
DOIs
StatePublished - May 2011
Externally publishedYes

Keywords

  • Amblyomma cajennense
  • Amblyomma dubitatum
  • Epidemiology
  • PCR
  • Ricketsia

ASJC Scopus subject areas

  • Parasitology
  • Microbiology (medical)
  • Infectious Diseases

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