Hepatitis C in a sexually transmitted infection clinic in Barcelona, Spain: analysis of the last decade

Objectives Hepatitis C virus (HCV) remains a global health concern, particularly among gay, bisexual and other men who have sex with men (GBMSM) with HIV or receiving HIV pre-exposure prophylaxis (PrEP). This study describes the sociodemographic, clinical and behavioural characteristics of HCV cases diagnosed at our clinic over a 10-year period and explores potential transmission networks. Methods Retrospective, descriptive, single-centre study including epidemiological, behavioural and clinical characteristics of HCV cases diagnosed at a Sexually Transmitted Infections (STI) Unit in Barcelona between January 2015 and December 2024. Data were summarised using descriptive statistics. Phylogenetic analysis was performed in HCV cases diagnosed between 2020 and 2024 with HCV RNA >1000 copies/mL and available blood samples to identify potential transmission networks. Results During the study period, 15 456 people were screened, leading to 100 HCV cases (68 newly acquired hepatitis, 13 newly acquired reinfections, 16 chronic infections and 3 unclassifiable) in 98 individuals (0.63% positivity rate). Among individuals, 98% were cisgender men and 90.7% GBMSM. By the end of the study, 64.8% were people with HIV and 24.2% had been in PrEP at some point of the follow-up. No or infrequent condom use was common (89.9%) and 65.3% reported drug use the 3–4 months prior to diagnosis. Among HCV cases, 41.2% had an ulcerative STIs at diagnosis. Of those treated, 96.3% achieved sustained virological response. Genotype 1a was the most common (44.2%) and phylogenetic analysis revealed potential transmission clusters of HCV subtype 1a but also 2c. Conclusions HCV remains frequent in our unit, particularly among GBMSM with HIV, GBMSM who use PrEP and those reporting condomless sex, drug use or concomitant STIs. Despite highly effective direct-acting antivirals, transmission within the GBMSM population persists. Enhanced prevention strategies, targeted education on safer sex and harm reduction strategies are essential.