Passive smoking, indoor air pollution and childhood tuberculosis: a case control study

Passive smoking and biomass fuel use most probably are more harmful to children than adults for two reasons. The first one is children's respiratory and immune systems are not fully developed. Secondly, they spend more time at home and are, therefore, likely to experience more intense and prolonged smoke exposure.

This study was planned to find out if there is any association between childhood tuberculosis and exposure to passive smoking and biomass fuel.

A hospital-based case control study was done. All registered consecutive newly diagnosed pediatric tuberculosis cases (0-14 years) from the outpatient department of a tertiary care hospital were recruited as cases. Age and sex matched controls were recruited from a public general hospital of the same locality. A semi-structured, pre-coded interview schedule was administered to parents or legal caregivers of all subjects after obtaining informed written consent.

A total of 200 cases and 200 controls were recruited in the study period. The factors which were significantly associated with development of tuberculosis were education of the mother, (OR 1.411, 95% CI 0.888-2.243, p-0.001), a family member having tuberculosis in the last two years and residing in the same house (OR 2.797, 95% CI 1.353-5.789; p-0.004), being a passive smoker (OR 1.725, 95% CI 1.142-2.605; p-0.009). No association between biomass cooking fuel use and development of tuberculosis was found.

Passive smoking is associated with development of childhood tuberculosis. This requires health education programmes and medical antitobacco advice and services.