Indoor Urban Environment and Conventional Risk Factors for Pediatric Tuberculosis Among 1-12 Years Old Children in a Megacity in Pakistan: A Matched Case-Control Study

Background: Estimated 1.1 million children developed tuberculosis (TB) globally in 2020. Household air pollution has been associated with increased respiratory tract infections among children. Nonetheless, there are scarce data regarding the association of indoor environment with pediatric TB. Objectives: To determine the association of indoor urban environment and conventional risk factors for pulmonary TB among children 1-12 years and to discern the differences of these factors among younger (1-5 years) and older children (6-12 years). Materials and Methods: We conducted an age-matched case-control study among children in 2 hospitals (tertiary and secondary care) in megacity, Karachi, Pakistan. A total of 143 pulmonary TB cases, diagnosed on Pakistan Paediatric Association Scoring Chart for Diagnosis of Tuberculosis (PPASCT), were compared with 286 age-matched controls (ratio 1:2). Indoor urban environment and other conventional risk factors were ascertained through a questionnaire and analyzed by conditional logistic regression. Results: Overall, being a female child [matched odds ratio (mOR): 2.03, 95% confidence interval (CI): 1.16-3.53], having household TB contact (mOR: 8.64, 95% CI: 4.82-15.49), open kitchen for cooking in household (mOR: 1.99, 95% CI: 1.59-5.66), and poorly ventilated house (mOR: 2.37, 95% CI: 1.09-3.65) increased the risk of TB among children (1-12 years). Open kitchen was a risk factor for younger children (1-5 years), whereas poorly ventilated house and being female child was a risk factor for older children (6-12 years), respectively. Conclusions: This study strengthens the evidence that a poor indoor environment increases the risk for childhood TB. Concerted efforts are needed to improve the indoor air environment in urban areas for prevention of TB in addition to addressing the conventional risk factors.