Trends in new hepatitis C virus infections among repeat blood donors - Georgia, 2017-2023.

Background and objectives: Blood donor cohorts are an underappreciated resource for surveillance and public health programming for infectious diseases. The incidence of hepatitis C virus (HCV) infection was evaluated in repeat blood donors in Georgia.

Materials and methods: Using data from the national hepatitis C screening registry, we calculated overall hepatitis C incidence for 2017-2023 and annual incidence during 2017-2022 among adults who donated blood at least twice and had a nonreactive HCV antibody (anti-HCV) test result upon first screening and a subsequent anti-HCV test conducted in any location. Rates of anti-HCV seroconversion and current infection were calculated by year, sex, age group, and location of last HCV screening and expressed per 100,000 person-years (PY).

Results: Of 101,443 blood donors with ≥2 anti-HCV results,775 (0.8%) seroconverted to anti-HCV reactive, of whom 403 (52.0%) had current infection. Incidence of anti-HCV seroconversion decreased from 408 per 100,000 PY in 2017 to 218 per 100,000 PY in 2022 and incidence of infection decreased from 172 per 100,000 PY in 2017 to 118 per 100,000 PY in 2022. Males, persons aged 18-39 years, and people last tested for HCV in prisons had the highest incidence rates for anti-HCV seroconversion and HCV infection, while persons last screened in blood banks and during antenatal care had the lowest.

Conclusion: Despite the observed decline, incidence of HCV infection among repeat blood donors remains high in specific subgroups. Hepatitis C prevention, screening and treatment interventions need to particularly focus on incarcerated populations and young adults in Georgia.