title: Risk factors associated with the transmission of Brazilian spotted fever in the Piracicaba river basin, State of São Paulo, Brazil.
abstract: BACKGROUND
  Brazilian spotted fever (BSF) is a disease transmitted by ticks for which the etiological agent is Rickettsia rickettsii. The present essay evaluates the risk factors associated with the transmission of cases of BSF in the time period between 2003 and 2013 in the Piracicaba river basin, state of São Paulo.
  
  
  METHODS
  This essay presents a retrospective study to identify the factors associated with the transmission of cases of BSF among all suspected cases identified by the System for Epidemiological Surveillance of São Paulo (CVE). After the description of temporal distribution (onset of symptoms) and the environmental and demographic variations of the confirmed and discarded cases, a multiple logistic regression model was applied.
  
  
  RESULTS
  We searched 569 probable locations of infection (PLI) with 210 (37%) confirmed cases of BSF and 359 (63%) discarded cases. The associated variables for the confirmation of BSF in the multiple logistic model using a confidence interval (CI) of 95% were age (OR = 1.025 CI: 1.015-1.035), the presence of Amblyomma sculptum in the environment (OR = 1.629 CI: 1.097-2.439), the collection of ticks from horses (OR = 1.939 CI: 0.999-3.764), the presence of capybaras (OR = 1.467 CI: 1.009-2.138), an urban environment (OR = 1.515 CI: 1.036-2.231), and the existence of a dirty pasture (OR = 1.759 CI: 1.028-3.003).
  
  
  CONCLUSIONS
  The factors associated with the confirmation of BSF cases included an urban environment, age, presence of the A. sculptum vector, the collection of ticks from horses, the presence of a capybara population, and a dirty pasture environment.
authors: Laboratório de Carrapatos, Superintendência de Controle de Endemias, Mogi Guaçu, SP, Brazil.
authors: Celso Eduardo de
authors: CE
authors: Souza
authors: Coordenação dos Laboratórios de Referência e Desenvolvimento Científico, Superintendência de Controle de Endemias, São Paulo, SP, Brazil.
authors: Adriano
authors: A
authors: Pinter
authors: Departamento de Saúde Coletiva, Faculdade de Ciências Médicas, Universidade de Campinas, Campinas, SP, Brazil.
authors: Maria Rita
authors: MR
authors: Donalisio
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D001938:Brazil / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006736:Horses; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D012189:Retrospective Studies; D012284:Rickettsia rickettsii / Q000302:isolation & purification*; D012307:Risk Factors; D012373:Rocky Mountain Spotted Fever / Q000453:epidemiology / Q000635:transmission*; D012377:Rodentia / Q000469:parasitology; D013987:Ticks / Q000382:microbiology*; D055815:Young Adult
chemical_list: D000907:Antibodies, Bacterial