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

Revista da Sociedade Brasileira de Medicina Tropical

Haydu, Valeska Bender¹  Labruna, Marcelo Bahia¹  Dumler, John Stephen¹  Toledo, Roberta Santos¹  Pacheco, Richard Campos¹  Tamekuni, Katia¹  Silva Filho, Mauro de Freitas¹  Universidade Estadual de Londrina, Londrina¹  The Johns Hopkins University School of Medicine, Baltimore, USA¹  Universidade de São Paulo, São Paulo¹  Vidotto, Odilon¹ 

关键词: Amblyomma dubitatum;    Amblyomma cajennense;    Rickettsia;    Epidemiology;    PCR;   

DOI  :  10.1590/S0037-86822011005000037

学科分类：农业科学（综合）

来源: Sociedade Brasileira de Medicina Tropical

【 摘 要 】

INTRODUCTION: 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 may be involved in transmission to humans.

【 授权许可】

Unknown