Prevalence, clinical characteristics, and treatment outcomes of childhood tuberculosis in Nigeria: a systematic review and meta-analysis

Background: Tuberculosis (TB), caused by Mycobacterium tuberculosis, is a leading cause of infection-related deaths worldwide. Children with underdeveloped immune systems are particularly vulnerable, experiencing symptoms akin to common childhood illnesses. Early diagnosis and treatment typically yield positive outcomes. In Nigeria, childhood TB is underreported, complicating accurate burden assessment. This review synthesises and presents evidence on the disease prevalence among children in Nigeria, identifies clinical characteristics, and evaluates the effectiveness of treatment regimens and outcomes.

Methodology: A comprehensive systematic search across electronic databases was conducted to retrieve studies on the prevalence, characteristics, diagnostic criteria, and treatment outcomes of childhood tuberculosis in Nigeria. Study registration, data extraction and quality assessment followed standardized guidelines. The meta-analysis used a random-effects model to determine prevalence and mean treatment outcomes. Statistical heterogeneity was assessed using the I² statistic, and publication bias was evaluated with Egger’s test (p = 0.127) and a funnel plot.

Results: This review and meta-analysis of 22 studies, primarily retrospective (77%) and cross-sectional (18.20%), involving 1,162,936 participants aged 0–18 years, found a pooled prevalence of 20.82% (95% CI: 8.55–36.64)) with high heterogeneity (I2 = 99.88%). Pulmonary tuberculosis is the most common form in children 62.70% (95%: 43.57–80.03) diagnosed using sputum smear microscopy, GeneXpert MTB/RIF assays, chest radiographs, and tuberculin skin tests. Clinical diagnosis based on symptoms, contact history, and radiological findings is crucial for younger children unable to produce sputum, as laboratory tests confirm only 6% of cases. Treatment involves the use of rifampicin, isoniazid, pyrazinamide, and ethambutol per national and international guidelines. The meta-analysis showed an average treatment success rate of 75.47%%, but challenges such as loss to follow-up (11.40%)) and increasing mortality rates (6.76%) persist.

Conclusion: The burden of childhood tuberculosis in Nigeria is significant, even as diagnostic limitations pose constraints. The findings highlight the need for stronger health system collaborations to improve the quality of care offered to children diagnosed with TB. Future research should standardize diagnostic criteria and methodologies for consistent and reliable prevalence estimates. More longitudinal studies are necessary to comprehend the trend and pattern for the heightened prevalence and subpar treatment outcomes of childhood tuberculosis in Nigeria.