Pulmonary versus extrapulmonary tuberculosis among diagnosed tuberculosis cases in Bangladesh: Evidence from a systematic review and meta-analysis

Background: Tuberculosis remains one of the primary infectious diseases in Bangladesh that affects both adults and children. Poor diagnostic criteria and insufficient reporting, especially of pulmonary tuberculosis (PTB) and extrapulmonary tuberculosis (EPTB) in children, limit the prevalence estimation, resulting in insufficient preventive strategies. This systematic review and meta-analysis aim to estimate the pooled proportions of PTB and EPTB among pediatric and adult diagnosed tuberculosis cases in Bangladesh, and to summarize the associated factors. Methods: We searched PubMed, Scopus, Cochrane Library, and BanglaJOL to retrieve articles published between January 1, 2000, and May 31, 2025. Eligible studies included retrospective studies that reported PTB and/or EPTB prevalence in pediatrics (<18 years) or adults (≥18 years) diagnosed tuberculosis cases in Bangladesh. We used the Joanna Briggs Institute Critical Appraisal Checklist for Prevalence Studies to assess the quality of the studies. Random-effects models estimated pooled proportions and I2, τ2, Cochran’s Q, and meta-regression assessed heterogeneity. Subgroup analyses compared proportion by age group. Results: Eleven studies (6 pediatrics, 5 adults) met the eligibility criteria. In patients with tuberculosis, the overall pooled proportion across all ages was 44.4% for PTB (95% CI: 35.9–53.3%; I2 = 93%) and 47.1% for EPTB (95% CI: 34.0–60.7%; I2 = 95%). Among pediatric populations, the pooled proportion of PTB was 44.5% (95% CI: 35.9–53.4%; I2 = 76%), while EPTB accounted for 55.5% (95% CI: 46.6–64.1%; I2 = 77%). In adults, PTB proportion was 44.2% (95% CI: 28.8–61.2%; I2 = 97%), and EPTB proportion was 37.4% (95% CI: 17.0–63.6%; I2 = 97%). Subgroup analysis revealed no significant difference in the proportions of PTB and EPTB between pediatric and adult groups. The most notable reported associations with PTB and EPTB in pediatrics included young age, exposure to tuberculosis patients, and male sex and, in adults, elderly age, female sex, low socioeconomic status, low education level, and comorbidities. Conclusions: Findings suggest a high proportion of PTB and EPTB in diagnosed tuberculosis cases in Bangladesh, with a relatively higher proportion of EPTB in children than adults. Key associated factors included exposure to tuberculosis patients, sex, low socioeconomic status, and other related comorbidities. Strengthening diagnostic capacity, expanding contact tracing, and addressing the associated factors through targeted public health interventions are necessary to enhance tuberculosis control efforts.