title: Outbreak of pulmonary tuberculosis in a Chinese high school, 2009-2010.
abstract: BACKGROUND
  In February 2009, a high school student was diagnosed with sputum-smear positive pulmonary tuberculosis (TB). One year later, 2 other students in the same grade developed sputum-smear positive TB.
  
  
  METHODS
  We used tuberculin skin testing (TST), chest radiography, sputum smear, and symptomatology for case identification. We defined latent TB infection (LTBI) as a TST induration of 15 mm or larger, probable TB as a chest radiograph indicative of TB plus productive cough/hemoptysis for at least 2 weeks or TST induration of 15 mm or larger, and confirmed TB as 2 or more positive sputum smears or 1 positive sputum smear plus a chest radiograph indicative of TB.
  
  
  RESULTS
  Of students in the same grade as the primary case-student, 26% (122/476) had LTBI and 4.8% (23/476) had probable/confirmed TB. Of teachers, 43% (18/42) had LTBI and none had probable/confirmed TB. Sharing a classroom with the primary case-student increased risk for LTBI (rate ratio = 2.5; 95% CI: 1.9-3.4) and probable/confirmed TB (rate ratio = 17, 95% CI: 7.8-39). Of students with LTBI in February 2009 who refused prophylaxis, 50% (11/22) had probable/confirmed TB in April 2010.
  
  
  CONCLUSIONS
  This TB outbreak was likely started by delayed diagnosis of TB in the case-student and was facilitated by lack of post-exposure chemoprophylaxis. Post-exposure prophylaxis is strongly recommended for all TST-positive students.
authors.affiliation: School of Public Health, Anhui Medical University, Hefei, China.
authors.forename: Yirong
authors.initials: Y
authors.lastname: Fang
authors.forename: Lijie
authors.initials: L
authors.lastname: Zhang
authors.forename: Chunyu
authors.initials: C
authors.lastname: Tu
authors.forename: Dongqing
authors.initials: D
authors.lastname: Ye
authors.forename: Robert
authors.initials: R
authors.lastname: Fontaine
authors.forename: Huilai
authors.initials: H
authors.lastname: Ma
authors.forename: Jiahu
authors.initials: J
authors.lastname: Hao
authors.forename: Lijun
authors.initials: L
authors.lastname: Fu
authors.forename: Xijun
authors.initials: X
authors.lastname: Ying
authors.forename: Qifeng
authors.initials: Q
authors.lastname: Chen
authors.forename: Yong
authors.initials: Y
authors.lastname: Wang
authors.forename: Huihui
authors.initials: H
authors.lastname: Liu
authors.forename: Bao-Ping
authors.initials: BP
authors.lastname: Zhu
mesh_terms: D002681:China / Q000453:epidemiology; D004196:Disease Outbreaks / Q000517:prevention & control*; D005260:Female; D006801:Humans; D055985:Latent Tuberculosis / Q000453:epidemiology; D008297:Male; D008403:Mass Screening / Q000379:methods; D056990:Post-Exposure Prophylaxis / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012574:Schools; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis / Q000453:epidemiology* / Q000517:prevention & control*