title: Study of infection by Rickettsiae of the spotted fever group in humans and ticks in an urban park located in the City of Londrina, State of Paraná, Brazil.
abstract: BACKGROUND
  Spotted fevers are emerging zoonoses caused by Rickettsia species in the spotted fever group (SFG). Rickettsia rickettsii is the main etiologic agent of Brazilian spotted fever (BSF)and it is transmitted by Amblyomma spp. ticks.
  
  
  METHODS
  The study aimed to investigate SFG rickettsiae in the Arthur Thomas 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 submitted for PCR in pools to analyze the Rickettsia spp. gltA (citrate synthase gene).
  
  
  RESULTS
  All the pools analyzed were negative. Human sera were tested by indirect immunofluorescence assay with R. rickettsii and R. parkeri as antigens.Among the 34 sera analyzed, seven (20.6%) were reactive for R. rickettsii: 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 staff, but no statistically significant associations were identified.
  
  
  CONCLUSIONS
  The serological studies suggest the presence of Rickettsiae related to SFG that could be infecting the human population studied; however, analysis of the ticks collected was unable to determine which species maybe involved in transmission to humans.
authors: Programa de Pós Graduação em Ciência Animal, Universidade Estadual de Londrina, Londrina, PR, Brasil.
authors: Roberta Santos
authors: RS
authors: Toledo
authors: Katia
authors: K
authors: Tamekuni
authors: Mauro
authors: M
authors: de Freitas Silva Filho
authors: Valeska Bender
authors: VB
authors: Haydu
authors: Richard Campos
authors: RC
authors: Pacheco
authors: Marcelo Bahia
authors: MB
authors: Labruna
authors: John Stephen
authors: JS
authors: Dumler
authors: Odilon
authors: O
authors: Vidotto
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood*; D001938:Brazil / Q000453:epidemiology; D004197:Disease Reservoirs / Q000145:classification / Q000382:microbiology*; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D016133:Polymerase Chain Reaction; D011633:Public Facilities; D012281:Rickettsia / Q000145:classification / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D012373:Rocky Mountain Spotted Fever / Q000453:epidemiology* / Q000635:transmission; D012377:Rodentia / Q000469:parasitology*; D013987:Ticks / Q000145:classification / Q000382:microbiology*; D014505:Urban Population
chemical_list: D000907:Antibodies, Bacterial