Geographic variation in risk factors for SFG rickettsial and leptospiral exposure in Colombia

Harish Padmanabha, Marylin Hidalgo, Gustavo Valbuena, Elizabeth Castaneda, Armando Galeano, Henry Puerta, Cesar Cantillo, Gilma Mantilla

Research output: Contribution to journalArticlepeer-review

23 Scopus citations


In order to characterize the patterns of human exposure to spotted fever group (SFG) rickettsial and leptospiral infection, IgG surveys were conducted on 642 residents of ten different areas of the rural district of Necoclí, Colombia. Areas were selected based on forest cover and human settlement pattern, and individual risk factors were elucidated through multivariate logistic models, controlling for variance clustering within communities. Overall, prevalence of high antibody titers indicating previous exposure to SFG rickettsia and leptospira was 29.2% and 35.6%, respectively, and both were most prevalent in the same peri-urban neighborhood. Forest cover >10% demonstrated the strongest independent association with leptospiral exposure, followed by homes with outdoor storage sheds. Isolated rural housing was the only variable independently associated with SFG rickettsia exposure. Community-level variables significantly modified the effects of individual risk factors. For both pathogens the eldest quartile was less exposed in periurban areas although there was no age effect overall for either. Females living in population settlements were more exposed to SFG rickettsiae but there was no sex association in isolated rural houses. Similarly, in sites with forest cover >10%, individuals working at home had higher leptospira seroprevalence, but place of work was not a risk factor in areas of forest cover <10%. These data suggest that the patterns of maintenance and/or exposure to leptospira and rickettsia vary across different human created landscapes and settlement patterns. While contrasting risk factors may reflect the unique transmission cycles of each pathogen, the observed patterns of geographic variation suggest that both diseases may respond similarly larger scale human-ecological dynamics.

Original languageEnglish (US)
Pages (from-to)483-490
Number of pages8
JournalVector-Borne and Zoonotic Diseases
Issue number5
StatePublished - Oct 1 2009
Externally publishedYes


  • Epidemiology
  • Modeling
  • Population
  • Rickettsia
  • Vector-borne
  • Zoonotic

ASJC Scopus subject areas

  • Microbiology
  • Infectious Diseases
  • Virology


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