RT Journal A1 Leung CC, Lam TH, Ho KS, et al T1 PAssive smoking and tuberculosis JF Archives of Internal Medicine JO Archives of Internal Medicine YR 2010 FD February 8 VO 170 IS 3 SP 287 OP 292 DO 10.1001/archinternmed.2009.506 UL http://dx.doi.org/10.1001/archinternmed.2009.506 AB Background  Increasing evidence has incriminated active smoking as a causal factor for tuberculosis (TB). However, the effect of secondhand tobacco smoke exposure on TB has not been similarly elucidated.Methods  A cohort of 15 486 female never-smokers aged 65 to 74 years and living with their surviving husband were enrolled at 18 Elderly Health Centers in Hong Kong from 2000 to 2003 and followed up prospectively through linkage with the territory-wide TB notification registry and death registry for TB and death until December 31, 2008, using an identity card number as a unique identifier. The relationship between passive smoking and the development of TB was assessed with adjustment for other baseline characteristics.Results  Passive exposure to secondhand tobacco smoke in the household was independently associated with obstructive lung disease (odds [OR], 1.43; 95% confidence interval [CI], 1.16-1.77) and diabetes mellitus (OR, 1.13; 95% CI, 1.02-1.26) at baseline and with the development of both active TB (hazard ratio [HR], 1.49; 95% CI, 1.01-2.19) and culture-confirmed TB (HR, 1.70; 95% CI, 1.04-2.80) on prospective follow-up after potentially confounding background variables were controlled for. Passive smoking accounted for 13.7% of active TB and for 18.5% of culture-positive TB in this cohort.Conclusions  Similar to active smoking, passive exposure to secondhand tobacco smoke in the household also predisposes to the development of TB. Increased emphasis should therefore be put on tobacco control in national TB programs.