Treatment outcomes of drug-resistant Mycobacterium tuberculosis infection in Cameroon: a systematic review and meta-analysis

Background: Drug-resistant tuberculosis (DR-TB) remains a major challenge to tuberculosis control in sub-Saharan Africa. Cameroon faces substantial challenges in managing DR-TB; however, national evidence on treatment outcomes remains unsynthesized. This systematic review and meta-analysis aimed to estimate pooled treatment outcomes, adverse drug events (ADEs), and predictors of unfavorable outcomes among patients with DR-TB in Cameroon. Methods: This systematic review and meta-analysis followed the PRISMA 2020 guidelines. PubMed, Scopus, Embase, Web of Science, the Cochrane Library, African Journals Online. Google Scholar and reference lists were also searched. Studies reporting World Health Organization-defined treatment outcomes among patients with DR-TB were included. Random-effects meta-analyses using generalized linear mixed models with logit transformation were performed. Heterogeneity was assessed using the I2 statistic, and publication bias and sensitivity analyses were conducted. Results: Fifteen studies conducted between 1998 and 2022 were included. The pooled mortality rate was 6.8% (95% CI: 4.7-9.7; 14 reports; n = 2,351 participants), loss to follow-up was 4.1% (95% CI: 2.8-6.1; 12 studies; n = 2,244 participants), and treatment failure was 5.0% (95% CI: 1.1-19.8; 12 studies; n = 2,050 participants). The pooled treatment success rate was 74.2% (95% CI: 60.4-84.4; 13 reports; n = 2,146 participants). Treatment success improved over time and was higher with modified regimens (87.2%; 95% CI: 83.8-89.9; 3 studies; n = 460 participants) than with standard regimens (68.8%; 95% CI: 52.2-81.6; 10 studies; n = 1,686 participants). Among patients with multidrug-resistant-TB, the pooled prevalence of adverse drug events was 70.8% (95% CI: 40.2-89.7; 3 studies; n = 251 participants), with ototoxicity (41.9%; 95% CI: 23.7-62.6; 3 studies; n = 251 participants) and gastrointestinal disorders (40.9%; 95% CI: 25.5-58.2; 2 studies; n = 172 participants) being the most common events. HIV co-infection was significantly associated with unfavorable treatment outcomes (pooled OR = 2.76; 95% CI: 1.95-3.93; 6 studies), and male gender was also associated with increased odds of unfavorable outcomes (OR = 1.73; 95% CI: 1.25-2.40; 5 studies). Conclusions: Approximately three-quarters of patients with DR-TB in Cameroon achieved successful treatment, although mortality, treatment failure, and adverse drug events remain important concerns. Strengthening pharmacovigilance, integrated TB/HIV care, and the implementation of effective all-oral regimens are essential to improve treatment outcomes. Systematic review registration number: CRD420261404490.