title: Validity of symptoms and radiographic features in predicting positive AFB smears in adolescents with tuberculosis.
abstract: METHODS
  A cohort of 78 adolescents was selected for evaluation with culture or histologically proven pulmonary tuberculosis (PTB) from a tertiary paediatric facility in northern Taiwan.
  
  
  OBJECTIVE
  To assess the validity of clinical features and radiographic findings for predicting positive smears of acid-fast bacilli (AFB) in adolescents with PTB.
  
  
  METHODS
  A retrospective descriptive study of adolescents with a confirmed diagnosis of PTB. Clinical symptoms and chest radiographs were assessed. Univariate analysis identified risk factors suggestive of a positive AFB smear, and the adjusted odds ratio (aOR) for these features was calculated using logistic regression.
  
  
  RESULTS
  Patients who were AFB smear-positive and those who were smear-negative differed significantly on univariate analysis (P < 0.05) with respect to chronic cough, haemoptysis, multilobar or superior segment of lower lobe involvement, cavitations or presence of pleural effusions. Logistic regression analysis revealed that risk factors of positive smear in adolescents with PTB were chronic cough >4 weeks (aOR 13.8, 95%CI 2.3-83.1), lower lobe involvement (aOR 12.6, 95%CI 1.2-134.8) and pulmonary cavitations (aOR 7.7, 95%CI 1.0-57.7).
  
  
  CONCLUSIONS
  For adolescents with PTB, those suffering from chronic cough for >4 weeks, with involvement of the superior segment of the lower lobe or with cavitary lesions, have a greater likelihood of transmitting tuberculosis due to smear positivity.
authors.affiliation: Department of Paediatrics, Chang Gung Memorial Hospital, Linkou, Taiwan; College of Medicine, Chang Gung University, Taoyuan, Taiwan. pchest@adm.cgmh.org.tw
authors.forename: K-S
authors.initials: KS
authors.lastname: Wong
authors.forename: Y-C
authors.initials: YC
authors.lastname: Huang
authors.forename: S-H
authors.initials: SH
authors.lastname: Lai
authors.forename: C-Y
authors.initials: CY
authors.lastname: Chiu
authors.forename: Y-H
authors.initials: YH
authors.lastname: Huang
authors.forename: T-Y
authors.initials: TY
authors.lastname: Lin
mesh_terms: D000293:Adolescent; D002648:Child; D015331:Cohort Studies; D003371:Cough / Q000453:epidemiology / Q000209:etiology; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012307:Risk Factors; D013183:Sputum / Q000382:microbiology*; D013624:Taiwan / Q000453:epidemiology; D013997:Time Factors; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000382:microbiology / Q000503:physiopathology