Epidemiology and Control of Hepatitis C Virus (Hcv) Infection in Brunei Darussalam: A Retrospective Cohort Study

Abstract Background We describe the epidemiology of hepatitis C virus (HCV) cases in Brunei Darussalam, and evaluated factors associated with HCV treatment initiation, completion, achieving sustained virologic response (SVR), baseline HCV-related complications, and HCV-related deaths. Methods A retrospective cohort study was conducted from January 2013 to December 2022 using data derived from EVYDENCE and the HCV registry to identify all diagnosed HCV cases in Brunei. Multivariable logistic regression was used to determine the associated factors. Results While incidence rates remained stable over a decade at below 20.0 per 100,000 population, we observed rising prevalence rates from 10.1 to 48.7 per 100,00 population in 2014 and 2022, respectively. Among 801 anti-HCV positive cases identified, 57% (n = 457) had detectable HCV RNA, 16.5% (n = 132) were HCV RNA negative, while 26.5% (n = 212) were not tested for HCV RNA. Treatment was initiated in 52.3% (n = 239) of HCV RNA positive cases, with higher odds among those aged 30–54 years [30–39 years (adjusted OR (aOR) = 2.41 (95% CI 1.17, 5.07)), 40–44 years (aOR = 2.55 (95% CI 1.19, 5.58)), 50–54 years (aOR = 2.76 (95% CI 1.25, 6.24))] and locals (aOR = 2.42 (95% CI 1.16, 5.36)). Cases diagnosed in 2020–2022 had lower odds of starting (aOR = 0.29 (95% CI 0.16, 0.51)) and completing (aOR = 0.16 (95% CI 0.05, 0.56)) treatment. Among 239 cases who initiated treatment, 69.5% (n = 166) completed treatment. 64.5% (n = 107) of these achieved SVR, with higher odds in cases diagnosed in 2018–2022 (aOR = 2.60 (95% CI 1.08, 6.90). 7.4% (n = 59) had HCV-related complications at baseline, with higher odds in those aged ≥ 50 (aOR = 3.32 (95% CI 1.93, 5.79). Among 129 deaths, 36.4% (n = 47) were HCV-related, of which 44.7% (n = 21) had HCV-related complications at baseline. Conclusions We observed rising HCV prevalence in Brunei, likely due to the decline in treatment initiation and completion. This reveals gaps in our HCV management and calls for actions to strengthen public health and clinical care strategies. Nearly half of the HCV deaths had baseline HCV-complications, highlighting the need for early screening and follow-up. Future studies should determine at-risk populations and explore barriers to HCV testing and care, to adequately address these issues and provide effective solutions.