Trends of drug-resistant tuberculosis and risk factors to poor treatment-outcome: a database analysis in Littoral region-Cameroon, 2013-2022.

INTRODUCTION

Tuberculosis(TB), currently has limited treatment options, and faces worldwide threat of drug-resistance(DR). In 2022, the DR-TB prevalence in Cameroon was 1.4% among new-cases and 8.3% among retreatment-cases. We analyzed the DR-TB database to descript the trends and DR-TB profile, treatment-outcome and associated risk-factors so-as-to propose measures to enhance program performance in Cameroon.

MATERIALS AND METHODS

We conducted a retrospective cohort study, analysed the DR-TB database of the Littoral region from 2013 to 2022. We appreciated the data-quality using zero-reporting, completeness, consistency, and validity indicators. We categorized DR-TB into Rifampicin-resistant-TB(RR-TB), multi-drug-resistant-TB(MDR-TB), pre-extensive-drug-resistant-TB(pre-XDR-TB), and XDR-TB and performed descriptive statistics. We assessed DR-TB treatment outcome targeting > 80% cure and/or completed treatment. Multiple logistic regression was used to determine risk factors related to poor treatment outcomes, and adjusted relative risk(RR) was considered significant at p < 0.05.

RESULTS

Overall database quality was 93.7% with uniqueness 100%, data-completeness 82.5%, consistency 97% and validity 95.1%. A total of 567 DR-TB cases were reported, with median age of 34 (1-80) years, male-to-female sex ratio (3:2). Cases were classified as 19(3.4%) RR-TB, 536(94.6%) MDR-TB, 7(1.3%) pre-XDR-TB, and 4(0.7%) XDR-TB. Case-reporting increased from 2013, reaching their peak in 2018. The overall treatment refusal rate was 123(11.9%) and treatment outcomes of 270(60.8%) cured, 116(26.4%) completed, 32(7.2%) deaths, 19(4.3%) lost-to-follow-up, and 6(1.4%) failure were recorded. We identified 84 dead (CFR:14.8%) amongst whom 52(62%) refused treatment, 17(20%) occurred during the first month of therapy and 13(15.5%) HIV-TB co-infected. Male gender [p = 0.006, RR = 2.5 (95% CI: 1.3-4.7)], HIV positive status [p = 0.012, RR = 2.1 (95% CI: 1.2-3.7)], and previous DR-TB status [p = 0.02, RR = 3.9 (95% CI: 1.3-12.0)] were statistically associated to poor treatment outcomes.

CONCLUSION

In the Littoral Region-Cameroon, cases of DR-TB increased from 2013, reaching their peak in 2018 befor dropping right up to 2022. RR-TB, MDR-TB, Pre-XDR-TB and XDR-TB represented 3.4%, 94.6%, 1.3% and 0.7% of all reported DR-TB cases. Overall, DR-TB treatment success rate was 87.2%. Male-gender, HIV-positive status, and previous DR-TB are associated with poor TB treatment outcomes. We recommend universal drug susceptibility testing to ensure early/maximum DR-TB case-detection and proper pre-treatment counselling to limit the high death rates and anti-TB treatment refusal rates which are setbacks from achieving end-TB strategies.