Second-hand smoke - increased risk of tuberculosis (TB)..

February 14, 2010 - Smoking has long been known to boost tuberculosis risk, and a new study from Hong Kong suggests that being exposed to someone else's tobacco smoke also increases the likelihood of contracting the disease.

Dr. Chi C. Leung of the Wanchai Chest Clinic in Wanchai and colleagues compared TB risk in older women living with at least one smoker to that of women living in smoke-free homes. The study included 15,486 non-smoking women 65 to 74 years old, all of whom lived with their husbands. All of the women had enrolled at one of the territory's 18 Elderly Health Centers between 2000 and 2003, and about one in four lived with a smoker. During follow-up, which lasted through the end of 2008 (or until a person died or was diagnosed with TB), 117 women developed active TB and 69 of these cases were confirmed in a laboratory.

Leung's team found that women who had been exposed to secondhand smoke were 1.5 times more likely to develop active TB than women who didn't live with a smoker, while their risk of culture-confirmed TB was 1.7-fold higher. Secondhand smoke exposure accounted for about 14 percent of active TB cases and about 18 percent of culture-confirmed TB cases.

The researchers also found that the women who lived with a smoker were significantly more likely to have some type of obstructive lung disease, such as emphysema, as well as diabetes, at the study's outset. Passive Smoking's Aggressive Side Secondhand Smoke Exposure Leads to Continuing Heart Risks, New Study Finds

PAPER: Passive Smoking and Tuberculosis, Chi C. Leung, MBBS; Tai H. Lam, MD; Kin S. Ho, MBBS; Wing W. Yew, MBBS; Cheuk M. Tam, MBBS; Wai M. Chan, MBBS; Wing S. Law, MBChB; Chi K. Chan, MBBS; Kwok C. Chang, MBBS; Ka F. Au, MBChB, Arch Intern Med. 2010;170(3):287-292, ABSTRACT..

Reference: Secondhand smoke raises TB risk: study, Reuters, 2/10/2010.

(ETS, enviromental tobacco smoke, second-hand smoke, SHS, involuntary smoking, sidestream smoke)