The ratio of hepatitis C virus genotypes in patients with HCV infection in St. Petersburg in 2024–2025

The ratio of hepatitis C virus (HCV) genotypes in the Russian Federation and in individual regions is a dynamic process that requires regular research within each region of the country. Such studies have become particularly relevant in the context of widespread access of patients with HCV infection to modern antiviral therapy. The aim of the study was to analyze the dynamics of the ratio of different HCV genotypes in patients with HCV infection in St. Petersburg in 2024-2025, as well as to evaluate gender and age indicators and the severity of liver fibrotic changes. Materials and methods. The retrospective continuous cross-sectional study included all patients with chronic HCV infection who were prescribed antiviral therapy (HTP) at the Botkin Clinical Infectious Diseases Hospital from 01.01.2024 to 31.12.2025 (n=4122). During the studied period, antiviral therapy was performed using various antiviral drugs (genotype-specific and pangenotypic), in accordance with current clinical guidelines of the Ministry of Health of the Russian Federation. Results. In 2024, the frequency of genotype 3a was 37.6%, 1b – 50.8%, 1a – 3.7%, 2 – 7.5%, unverified – 0.4%, mixed genotypes were not registered. In 2025– 3a – 46.8%, 1b – 37.8%, 1a – 5.1%, 2 – 9.9%, unverified – 0.2%, mixed – 0.1% (χ 2 =71.244, p<0.001). Patients with different genotypes significantly differed in age: the youngest were patients with genotype 1a, 45 (41; 50) years old, followed by patients with genotype 3a, 49 (44; 56) years old, genotype 1b, 56 (47; 65) years old, and genotype 2, 57 (49; 66) years (Kruskal-Wallis Н 323,881, p<0.001). In 2025, patients were slightly younger than in 2024: 51 (45; 60) years old versus 52 (45; 62) years old (Mann-Whitney U 1917299.0, p=0.015). Men slightly prevailed – 53%, women made up 47%. There was no significant change in the male/female ratio in 2025 compared to 2024. Fibrosis of stage 0-1 was detected in 50.3%, stage 2 – 27.4%, stage 3 – 10.5%, stage 4 – 11.8%. In 2025, compared to 2024, the number of patients with 0-1 fibrosis decreased and increased with other stages of fibrosis (χ 2 =10.943, p=0.012). Conclusion . A decrease in the proportion of patients with genotype 1b and an increase in patients with genotype 3a over the period 2024-2025 was revealed, with a slight increase in the proportion of genotypes 2 and 1a, as well as a decrease in the dynamics of patient age, the absence of significant changes in the gender structure, and an increase in the proportion of patients with moderate and severe stages of fibrosis. The decrease in the proportion of genotype 1b is probably related to the wider treatment of HCV genotype 1b patients in 2024.