Systematic review and meta-analysis of the associations between indoor air pollution and tuberculosis.

OBJECTIVE: Half the world's population uses biomass fuel for their daily needs but the resultant emissions and indoor air pollution (IAP) are harmful to health. So far, evidence for a link between IAP and tuberculosis (TB) was insufficient. We report an updated systematic review due to recent increase in the evidence and growing interest in testing interventions. METHODS: Systematic search of PubMed (including Medline), CAB abstracts (through Ovid SP) and Web of Knowledge using the following search terms: 'IAP or biomass or cooking smoke' and 'TB'. 452 abstracts were reviewed, and only 12 articles were deemed to be reporting the effects of IAP on TB and were taken forward to full review, and one study was added through hand search of references. Data on measures of effect of IAP on TB were extracted, and meta-analysis was carried out to estimate pooled measures of effect. RESULTS: Thirteen studies have reported investigating association between IAP and TB since 1996. TB cases are more likely to be exposed to IAP than healthy controls (pooled OR 1.30; 95% CI, 1.04-1.62; P = 0.02). CONCLUSIONS: There is increasingly strong evidence for an association between IAP and TB. Further studies are needed to understand the burden of TB attributable to IAP. Interventions such as clean cook stoves to reduce the adverse effects of IAP merit rigorous evaluation, particularly in Africa and India where the prevalence of IAP and TB is high.