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

Background

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, Cochrane Library, and African Journals Online were 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, most of which were observational cohort studies. The pooled mortality rate was 6.8% (95% CI: 4.7–9.7; 14 reports; n = 2,351 participants; I2 = 58.1%), loss to follow-up was 4.1% (95% CI: 2.8–6.1; 12 reports; n = 2,244 participants; I2 = 55.5%), and treatment failure was 4.2% (95% CI: 1.1–14.3; 13 reports; n = 2,050 participants; I2 = 93.3%). The pooled treatment success rate was 74.2% (95% CI: 60.4–84.4; 13 reports; n = 2,146 participants; I2 = 88.1%). 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 sex 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 DR-TB patients in Cameroon achieved treatment success under standard regimens, falling short of the 85% target in the 2024–2026 National Strategic Plan. With mortality, treatment failure, and adverse drug events remaining major concerns, strengthening pharmacovigilance, integrating TB/HIV care, and implementing all-oral regimens are essential to improve outcomes and meet national targets.