Programmatic management of rifampicin-resistant tuberculosis with standard regimen in Cameroon: a retrospective cohort study

Int J Infect Dis. 2022 Nov:124:81-88. doi: 10.1016/j.ijid.2022.09.012. Epub 2022 Sep 13.

Abstract

Objectives: To describe treatment outcomes for rifampicin-resistant tuberculosis (Rr-TB) started on standard regimen and the frequency of acquired drug resistance in patients treated using the standard treatment regimen (STR) in Cameroon between 2015-2019.

Methods: This is a retrospective cohort study. Rr-TB patients were initiated on the STR, including a fluoroquinolone (FQ), a second-line injectable drug (SLI), and companion drugs. In case of resistance to fluoroquinolones (FQr) at baseline, FQ, SLI and ethionamide were replaced by bedaquiline, delamanid, and linezolid in a modified treatment regimen (mTR), FQr-mTR. In case of resistance to SLI (SLIr) at baseline, SLI was replaced by linezolid (LZD), SLIr-mTR. Logistic regression and competing risk regression were used to estimate predictors of early (first eight weeks) mortality and overall mortality, respectively.

Results: Of 709 patients started on a standard regimen, treatment success occurred in 84.7% (587/693), 72.7% (8/11) and 100% (10/10) of patients treated with STR, FQr-mTR and SLIr-mTR as final regimens, respectively. Three (0.6%) patients acquired FQr during treatment. Early mortality occurred in 4.1% (29/709) and was associated with being HIV positive, male sex and being underweight. Overall mortality was associated with missing drug-susceptibility testing results at baseline, being HIV positive, age>40 and male sex.

Conclusion: Programmatic management of Rr-TB, with additional second-line drug resistance treated with mTR, resulted in excellent treatment outcomes.

Keywords: Cameroon; Fluoroquinolone and second-line injectable resistance; Rr-TB; Standard regimen.

MeSH terms

  • Adult
  • Antitubercular Agents / therapeutic use
  • Cameroon / epidemiology
  • Fluoroquinolones / therapeutic use
  • HIV Infections* / drug therapy
  • Humans
  • Linezolid / therapeutic use
  • Male
  • Retrospective Studies
  • Rifampin / therapeutic use
  • Treatment Outcome
  • Tuberculosis, Multidrug-Resistant* / drug therapy

Substances

  • Rifampin
  • Antitubercular Agents
  • Linezolid
  • Fluoroquinolones