Resum

Background Ongoing high-risk behaviors continue to fuel HCV transmission among men who have sex with men (MSM), challenging elimination efforts. We studied HCV epidemiology in MSM with HIV (MSM-WH) and without HIV in the region of Madrid. Methods This prospective study (2022–2024) enrolled MSM-WH from 10 centers and MSM on PrEP from an STI clinic. Visits were scheduled at baseline, 3, 6, 9, and 12 months (PrEP group), or baseline, 6, and 12 months (HIV group). Assessments included liver enzymes, HCV serology, HCV-RNA, and STI screening (syphilis, chlamydia, and gonorrhea by PCR). Results A total of 1,372 MSM (733 with HIV; 639 on PrEP) were enrolled. Baseline HCV prevalence was 1.68%, significantly higher in those with prior HCV exposure (5.60% vs. 0.72%; prevalence ratio: 7.72, 95% CI: 3.31–18.03). Over 1,240.4 person-years (PY) of follow-up, overall HCV incidence was 1.45/100 PY. Primary infection incidence was 0.79/100 PY: 0.94 in PrEP users vs. 0.65 in MSM-WH (IRR: 1.44, 95% CI: 0.24–9.80). Reinfection incidence was 4.32/100 PY overall: 12.90 in PrEP users and 4.05 in MSM-WH (IRR: 3.21, 95% CI: 0.07–22.53). Two participants experienced within study reinfection (8.7/100 PY, 95% CI: 1.05–31.4). Slamsex and condomless receptive anal intercourse with =4 partners were independently associated with HCV infection and reinfection. Conclusions MSM with prior HCV exposure had markedly higher HCV prevalence and incidence, regardless of HIV status. Risky sexual behaviors remain key drivers of HCV transmission. Behavior-informed prevention strategies are critical to sustain elimination efforts in MSM populations.