Dynamic changes in the prevalence of markers of hepatitis C virus infection among the conditionally healthy population of the Tyva Republic

Abstract

The aim is to determine the dynamic changes in the prevalence of hepatitis C virus (HCV) infection among various age groups of the conditionally healthy population of the Tyva Republic over the past 11 years.Material and methods. 1163 serum samples collected in 2019 from the healthy volunteers living in the Tyva Republic of were tested for HCV markers. The study included people of 10 age cohorts: less than 1 year, 1-4, 5-9, 10-14, 15-19, 20-29, 30-39, 40-49, 50-59 years, and 60 years or older. Anti-HCV antibodies were detected using commercially available enzyme immunoassay. HCV RNA was detected in anti-HCV positive samples by means of RT-PCR. The dynamic changes in HCV prevalence were assessed based on a comparison of the results with data of the seroservey of the same design conducted in this region in 2008 in similar age cohorts of healthy volunteers (n=910).Results and discussion. The prevalence of anti-HCV antibodies among general population of the Tyva Republic in 2019 was 2.0%. This indicator slightly decreased by 1.7 times over 10 years (3.3% in 2008, p =0.1629). The prevalence of active HCV infection in the Tyva Republic also decreased not significantly (1.1% in 2019 vs. 1.3% in 2008, p = 0.6901). The proportion of people with active infection among anti-HCV positives in 2019 was 56.5%.The decrease in the prevalence of HCV infection over 11 years was associated with a significant reduction in the detection rates of hepatitis C markers in age cohort 40-49 years (0.9% in 2019 vs. 3.6% in 2008 for HCV RNA, p<0.05, and 1.8% in 2019 vs. 9.1% in 2008 for anti-HCV, p<0.05, respectively). The highest rates of detection of anti-HCV and HCV RNA were observed among participants aged 60 years and over (8.0% and 7.0%, respectively, in 2019 and 11.0 and 6.3%, respectively, in 2008), which significantly exceeded detection rates in other age groups, both in 2008 and 2019 (<0.05).Conclusion. A decrease in the prevalence of HCV infection in general population of the Tyva Republic was observed over last 11 years, primarily due to a decrease in the proportion of unidentified cases of infection among people aged 40-49 years. At the same time, the proportion of unidentified cases of HCV infection in persons aged 60 years and older remains consistently high, which is apparently due to insufficient screening coverage in this age cohort. This age-associated risk cohort should be benefited from the inclusion in HCV screening program.