Acute hepatitis C (AHC) has emerged as a relevant sexually transmitted infection (STI) among men who have sex with men (MSM), particularly linked to condomless anal practices and chemsex. Data on AHC in HIV pre-exposure prophylaxis (PrEP) users in our setting are scarce.
We conducted a descriptive case series study of AHC events identified within a PrEP user cohort followed between November 2019 and February 2025 at Hospital Clínic de Barcelona. Cases of AHC were identified, and their socio-demographic, clinical and behavioural profiles were described.
A total of 2003 individuals were enrolled in the PrEP programme during this period. The cohort was predominantly composed of cisgender MSM (96%), with a median age of 32 years, and 46% were born in Spain. Regarding sexual practices and substance use, 59% reported drug use, 82% of whom practised chemsex. Additionally, group sex and condomless anal sex were reported in 59% and 61% of participants, respectively. At baseline, 26% of patients tested positive for Chlamydia trachomatis (CT) or Neisseria gonorrhoeae (NG). Seven individuals (0.35%) had hepatitis C virus (HCV)-antibody positive with undetectable viraemia.
During follow-up, 11 cases of AHC were diagnosed, yielding an incidence of 0.34 cases per 100 person-years (95% CI 0.17 to 0.61). All cases occurred in cisgender MSM, of whom 75% reported chemsex, 80% condomless group sex and 1 injecting drug use. STI coinfection was observed in 73% of AHC cases: 4 CT, 3 NG and 2 Treponema pallidum. Antiviral HCV treatment was effective in all cases, with no reinfections reported.
The incidence of AHC among PrEP users is not negligible and most cases reported substance use and sexual practices such as condomless sex and group sex. These findings highlight the need to reinforce systematic screening in this key population and adopt a multidisciplinary approach for an effective response.