title: Tuberculin reactivity in first-year schoolchildren in Madagascar.
abstract: OBJECTIVE
  The tuberculin skin test (TST) is an important tool in the diagnosis of tuberculosis infection in children. However, the interpretation of TST may be complicated by prior Bacillus Calmette-Guerin (BCG) vaccination. We evaluated the effect of vaccination with BCG on TST reactivity in first-year pupils attending state schools in Antananarivo.
  
  
  METHODS
  STs were performed on 376 first-year schoolchildren, aged 6 and 7, attending two state primary schools. The relationships between epidemiological information, BCG status (vaccination, BCG scars) and TST reactivity were assessed to compare TST sensitivity between children with and without BCG vaccination and between those with and without a BCG scar.
  
  
  RESULTS
  The prevalence of positive TST results of ≥5, ≥10 and ≥ 15 mm was 20.2% (76/376), 18.3% (69/376) and 11.4% (43/376), respectively. BCG vaccination was not associated with TST reactivity, whatever the threshold used: ≥5 mm (odds ratio (OR, 1.2; 95% confidence interval (CI), 0.7-2.0); ≥10 mm (OR, 0.9; 95% CI, 0.6-1.7); ≥15 mm (OR, 0.6; 95% CI, 0.3-1.2).
  
  
  CONCLUSIONS
  These results suggest that in Madagascar, a positive TST result indicates TB infection (active or latent) rather than past BCG vaccination. Therefore, high BCG vaccination coverage does not appear to impair the usefulness of the TST as a tool for diagnosing tuberculosis.
authors.affiliation: Pasteur Institute of Madagascar, Antananarivo, Madagascar.  
authors.forename: Vaomalala
authors.initials: V
authors.lastname: Raharimanga
authors.forename: Rila
authors.initials: R
authors.lastname: Ratovoson
authors.forename: Maherisoa
authors.initials: M
authors.lastname: Ratsitorahina
authors.forename: Herimanana
authors.initials: H
authors.lastname: Ramarokoto
authors.forename: Voahangy
authors.initials: V
authors.lastname: Rasolofo
authors.forename: Antoine
authors.initials: A
authors.lastname: Talarmin
authors.forename: Vincent
authors.initials: V
authors.lastname: Richard
mesh_terms: D001500:BCG Vaccine / Q000008:administration & dosage*; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008270:Madagascar; D008297:Male; D009169:Mycobacterium tuberculosis / Q000276:immunology; D016017:Odds Ratio; D011237:Predictive Value of Tests; D014373:Tuberculin / Q000276:immunology; D014374:Tuberculin Test / Q000379:methods*; D014376:Tuberculosis / Q000175:diagnosis* / Q000276:immunology / Q000517:prevention & control; D014611:Vaccination / Q000379:methods
chemical_list: D001500:BCG Vaccine; D014373:Tuberculin