title: Nested case-control study in a serological survey to evaluate the effectiveness of a Chagas disease control programme in Brazil.
abstract: OBJECTIVE
  To identify risk factors associated with Trypanosoma cruzi infections in areas under surveillance in the State of Minas Gerais, Brazil.
  
  
  METHODS
  A model using a nested case-control design incorporated within a serological survey of schoolchildren which was employed to evaluate the effectiveness of the Chagas disease control programme.
  
  
  RESULTS
  In a sample of 40,374 schoolchildren (aged 7-14 years) surveyed, 16 children tested positive for T. cruzi antibody (by indirect immunofluorescence and indirect haemagglutination). In the case-control study, each case was randomly matched to three seronegative controls (classroom and age +/- 1 year). Compared to controls, T. cruzi-seropositive children were more likely to have a seropositive mother (odds ratio (OR) = 6.8; 95% confidence interval (CI) = 0.71-63.9) or a seropositive family member (OR = 8.6; 95% CI = 1.0-75.5).
  
  
  CONCLUSIONS
  Use of the nested case-control model in a sero-epidemiological survey to evaluate risk factors for T. cruzi transmission was adequate for assessing the effectiveness of a Chagas disease control programme.
authors: Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Caixa Postal 486, 31270-901-Belo Horizonte, MG, Brazil. mcarneir@icb.ufmg.br
authors: M
authors: M
authors: Carneiro
authors: E C
authors: EC
authors: Moreno
authors: C M
authors: CM
authors: Antunes
mesh_terms: D000293:Adolescent; D001938:Brazil / Q000453:epidemiology; D016022:Case-Control Studies; D014355:Chagas Disease / Q000175:diagnosis / Q000453:epidemiology / Q000517:prevention & control*; D002648:Child; D003140:Communicable Disease Control; D005260:Female; D006801:Humans; D008297:Male; D011159:Population Surveillance; D015397:Program Evaluation / Q000379:methods*; D012307:Risk Factors