Up-to-date Epidemiology of Chronic Hepatitis C Virus Infection among Bulgarian Patients: a Single Centre Experience

Epidemiological data about chronic infection with Hepatitis C virus (HCV) are limited in Bulgaria. The aim of this study was to determine the Viremic Rate and the distribution of HCV genotypes in one centre for diagnosis and treatment of chronic liver diseases. Geographic patterns of genotype distribution and associations of genotype with viral load, gender and age were investigated. Serum samples from 1731 individuals with a positive HCV Antibody Test, collected between 2016 and 2019, were analysed. HCV RNA levels were determined by HCV quantitative RNA real time polymerase chain reaction. Individuals with detectable HCV RNA further underwent HCV genotyping analysis using the Versant HCV Genotype Assay (LiPA) 2.0. The mean age of all patients was 52.9±15.3 (17–87). Among those, 54.1% were men and 45.9% women. Most patients came from the south-western region of Bulgaria (21.7%). Viral load was proven in 1385 out of 1731 individuals (VR=80%). Genotype 1 (G1) was the predominant genotype (89.8%), followed by G3 (8.5%), G2 (0.9%), G4 (0.6%) and G5 (0.1%). Among individuals with G1, infection with subtype 1b was seen in 77.4% and with subtype 1a in 22.6%. Viral load was not found to be dependent on age or gender. Viral load was higher in patients with G1 compared to G3 ($$p=0.001$$). Finally, patients with G1b were significantly older than patients with G1a ($$p<0.001$$) and G3 ($$p<0.001$$). VR in the studied population (80%) appears to be higher than the VR reported for Central Europe (73.3%). In Bulgaria, the most prevalent genotype is G1 (89.8%). This is a higher rate in comparison to the observed G1 rate in Central Europe (70%). The second most prevalent genotype is G3 (8.5%), with fewer cases identified than in Central Europe (21%).