Effectiveness of Bacillus Calmette Guerin (BCG) vaccination in the prevention of childhood pulmonary tuberculosis: a case control study in Nagpur, India.
A hospital-based, pair matched, case control study was carried out to estimate the effectiveness of BCG vaccination in the prevention of childhood pulmonary tuberculosis. The study included 126 incident cases of pulmonary tuberculosis (diagnosed by WHO criteria) below/equal the age of 12 years. Each case was pair matched with one control for age, sex, socio-economic status. Controls were selected from subjects attending study hospital for conditions other than tuberculosis and leprosy. The significant protective association between BCG and childhood pulmonary tuberculosis was observed (OR = 0.39, 95% CI = 0.22, 0.68). The overall vaccine effectiveness was 61% (95% CI = 32%, 78%). BCG was nonsignificantly more effective in underfives, among males and in upper-middle socioeconomic strata. The overall prevented fraction was estimated to be 47.53% (95% CI = 21.41%, 67.25%). Results of this study thus demonstrated a moderate effectiveness of BCG vaccination in prevention of childhood pulmonary tuberculosis in a Central India population.