Tuberculosis treatment outcome in Cameroon: a systematic review and meta-analysis

Background: Tuberculosis (TB) remains a major public health challenge in Cameroon, yet national evidence on treatment outcomes across the full spectrum of routine care is limited. This systematic review and meta-analysis estimated pooled proportions of treatment success, mortality, treatment failure and loss to follow-up (LTFU) among TB patients in Cameroon, and identified predictors of unfavorable outcomes. Methods: PubMed, Embase, Scopus, Web of Science, African Journals Online and the Cochrane Library were searched, supplemented by Google Scholar and reference-list screening. Observational studies conducted in Cameroon reporting at least one WHO-defined treatment outcome were eligible. Pooled proportions and adjusted odds ratios (AOR) were estimated with random-effects models meta-analysis. Data were analyzed using R Statistics version 4.6.1. Results: Thirty-two studies (25 cohorts, 7 cross-sectional), conducted between 1998 and 2022 across six of Cameroon's ten regions, were included. Pooled treatment success was 78.2% (95% CI: 73.8-82.1; 27 reports; 71,784 participants; I2= 98.2%), mortality 8.1% (95% CI: 5.5-11.7; 25 reports; 71,870 participants; I2 = 97.8%), treatment failure 0.9% (95% CI: 0.5-1.4; 26 reports; 71,389 participants; I2 = 89.1%) and LTFU 6.8% (95% CI: 5.0-9.1; 26 reports; 70,768 participants; I2 = 98.6%). Mortality was highest in the South-West (16.2%) and among TB/HIV-coinfected patients (30.5%), and lowest among children (5.0%). Treatment success was lowest in the Littoral (71.1%) and among TB/HIV-coinfected patients (60.8%) and highest among multidrug-resistant TB (89.3%) and pediatric patients (86.8%). Treatment failure significantly declined from 2.9% before 2005 to 0.5% from 2020 onward (p < 0.001). Significant predictors of unfavorable outcomes were HIV positivity (AOR = 2.57; 95% CI: 1.86-3.55), previous TB treatment (AOR = 1.99; 95% CI: 1.40-2.84), male sex (AOR = 1.67; 95% CI: 1.45-1.92), age ≤40 years (AOR = 1.45; 95% CI: 1.06-1.98) and absence of antiretroviral therapy (AOR = 1.71; 95% CI: 1.15-2.54). Conclusions: TB treatment outcomes in Cameroon remain suboptimal, with nearly one in five patients not achieving treatment success and high mortality among TB/HIV-coinfected individuals. Strengthening TB/HIV service integration, early antiretroviral therapy initiation, targeted support for previously treated patients and men, and improved retention in care are needed. Systematic review registration number: CRD420261404490