Interim effect evaluation of the hepatitis C elimination programme in Georgia: a modelling study

Abstract

Background: Georgia has a high prevalence of hepatitis C, with 5·4% of adults chronically infected. On April 28, 2015, Georgia launched a national programme to eliminate hepatitis C by 2020 (90% reduction in prevalence) through scaled-up treatment and prevention interventions. We evaluated the interim effect of the programme and feasibility of achieving the elimination goal.

Methods: We developed a transmission model to capture the hepatitis C epidemic in Georgia, calibrated to data from biobehavioural surveys of people who inject drugs (PWID; 1998-2015) and a national survey (2015). We projected the effect of the administration of direct-acting antiviral treatments until Feb 28, 2019, and the effect of continuing current treatment rates until the end of 2020. Effect was estimated in terms of the relative decrease in hepatitis C incidence, prevalence, and mortality relative to 2015 and of the deaths and infections averted compared with a counterfactual of no treatment over the study period. We also estimated treatment rates needed to reach Georgia's elimination target.

Findings: From May 1, 2015, to Feb 28, 2019, 54 313 patients were treated, with approximately 1000 patients treated per month since mid 2017. Compared with 2015, our model projects that these treatments have reduced the prevalence of adult chronic hepatitis C by a median 37% (95% credible interval 30-44), the incidence of chronic hepatitis C by 37% (29-44), and chronic hepatitis C mortality by 14% (3-30) and have prevented 3516 (1842-6250) new infections and averted 252 (134-389) deaths related to chronic hepatitis C. Continuing treatment of 1000 patients per month is predicted to reduce prevalence by 51% (42-61) and incidence by 51% (40-62), by the end of 2020. To reach a 90% reduction by 2020, treatment rates must increase to 4144 (2963-5322) patients initiating treatment per month.

Interpretation: Georgia's hepatitis C elimination programme has achieved substantial treatment scale-up, which has reduced the burden of chronic hepatitis C. However, the country is unlikely to meet its 2020 elimination target unless treatment scales up considerably.

Funding: CDC Foundation, National Institute for Health Research, National Institutes of Health.

Figure 1

Schematics of state transitions in the model (A) Infection compartments, (B) liver disease state compartments, (C) PWID and age compartments. Gender compartments are not shown. Dotted lines indicate transition to death. ex-PWID=people who used to inject drugs. Non-PWID=people who have never injected drugs. PWID=people who inject drugs.

Figure 2

Chronic hepatitis C prevalence and incidence among adult PWID and the overall adult population over time Data are prevalence (95% CI) or incidence (95% CI). Model projections for current treatment (red line) incorporate actual treatment numbers from May 1, 2015, to Feb 28, 2019, and assume a treatment rate of 1000 individuals initiating treatment per month continuing from March, 2019. CrI=credible interval. HCV=hepatitis C virus. PWID=people who inject drugs.

Figure 3

Model projected interim effect at the end of February, 2019, and future effect of different treatment scenarios at the end of 2020 (A) Cumulative chronic hepatitis C treatments, (B) adult chronic hepatitis C prevalence, (C) adult hepatitis C incidence, and (D) annual hepatitis C mortality over time. x-axis tick marks indicate the beginning of each labelled year. CrI=credible interval.

Figure 4

Percent reduction in chronic hepatitis C prevalence (A), incidence (B), and mortality (C) from 2015, to the end of 2020, under different treatment strategies initiating in March 1, 2019 Data are median (credible interval). The no treatment (yellow) scenario (from 2015) is also shown, otherwise scenarios assume achieved treatment rates until February, 2019, followed by continuing treatment at indicated rate from March, 2019.

Figure 5

Sensitivity analysis of treatment rate needed under alternative model scenarios in comparison with baseline model to reach a 90% reduction in chronic hepatitis C prevalence by end of 2020 Data are median (credible interval). Treatment rates are for March, 2019, onwards except for the scenario, delay scale-up by 6 months, in which the treatment rate continues at 1000 individuals starting treatment per month until September, 2019, and then is scaled up. In scenario, exclude PWID, elimination is not possible at any level of treatment scale-up. NSP=needle and syringe programme. OST=opioid substitution therapy. PWID=people who inject drugs. SVR=sustained viral response.