Temporal trends in hepatitis C incidence among people tested more than once in Georgia, 2017-23: a nationwide, retrospective cohort.

BACKGROUND

Achieving low incidence is one of WHO's key targets for the elimination of hepatitis C virus (HCV) infection. As progress in Georgia's hepatitis C elimination programme moves the country closer to reaching this target, tracking new cases of hepatitis C has become a priority. We aimed to estimate temporal trends in hepatitis C incidence among people who were tested more than once for hepatitis C in Georgia.

METHODS

We conducted a retrospective cohort study in adults (aged ≥18 years) tested at least twice for antibodies against HCV (anti-HCV), with the first test being non-reactive, in Georgia from Jan 1, 2017, to Dec 31, 2023. Data were extracted from Georgian national hepatitis C screening and treatment databases on Jan 8, 2024. We calculated the incidence of anti-HCV seroconversion and current chronic HCV infections per 100 000 person-years and 95% CIs overall for 2017-23 and by year for 2017-22. For people who seroconverted but did not undergo testing to confirm current infection, we used multiple imputations to impute the status of current chronic HCV infection. To estimate the magnitude of change, we calculated incidence rate ratios (IRRs) with 95% CIs.

FINDINGS

Among 1 264 181 adults with repeat anti-HCV testing during the study period, 519 936 (41·1%) were men and 744 245 (58·9%) were women. In total, 18 846 (1·5%) seroconverted to anti-HCV-reactive after a median follow-up time of 1025 days (IQR 503-1553). The overall incidence rate of anti-HCV seroconversion was 514 cases per 100 000 person-years (95% CI 506-521). The overall estimated incidence rate of current chronic HCV infection was 293 cases per 100 000 person-years (288-299). The annual incidence rate of anti-HCV seroconversion was 3·7 times lower in 2022 than in 2017, declining from 1399 cases per 100 000 person-years (1346-1454) to 377 cases per 100 000 person-years (361-394; IRR 0·27 [95% CI 0·25-0·29]). The annual incidence rate of chronic HCV infection was 4·6 times lower in 2022 than in 2017, declining from 935 cases per 100 000 person-years (892-981) to 205 cases per 100 000 person-years (193-217; IRR 0·22 [95% CI 0·20-0·24]).

INTERPRETATION

We found a high but decreasing incidence rate of hepatitis C in Georgia among people tested more than once. The country should scale up preventive interventions to reduce incidence further and reach elimination targets.

FUNDING

None.

TRANSLATION

For the Georgian translation of the abstract see Supplementary Materials section.