Pooled estimates of hepatitis C incidence among gay and bisexual men using PrEP by country-level availability of hepatitis C DAA treatment: a systematic review and meta-analysis

BACKGROUND: Sexual transmission of hepatitis C virus (HCV) among gay and bisexual men (GBM) has been historically concentrated among people living with HIV, but concerns exist that the widespread scale-up of PrEP may increase HCV incidence among HIV-negative GBM. Given community-level HCV viremia at the time of PrEP scale-up is likely to moderate risk among PrEP users, we examined the impact of broad DAA availability on HCV incidence in studies of GBM using PrEP.
METHODS: We searched PubMed, Medline, EMBASE and relevant conference databases to 9^th August 2021 for studies reporting HCV incidence among GBM using PrEP (daily or event-driven). Cohort studies and open-label clinical trials were included. Pooled estimates of HCV incidence were calculated using random-effects meta-analysis. Using a literature and policy review of the timing of broad/universal HCV DAA availability in included countries, we conducted a subgroup analysis of PrEP studies that commenced participant follow-up before or after country-level DAA availability.
RESULTS: Seventeen studies published between 2015-2021 reported on HCV incidence among GBM using PrEP and were included; all were from high-income countries. One study reported HCV incidence among daily and event-driven PrEP users separately and was included as two observations in the meta-analysis. Overall 18,363 participants were included; 145 incident HCV infections were captured over 24,023 person-years. The pooled estimate of HCV infection across studies was 0.91 per 100 person-years (range, 0.00 to 2.93/100py). Heterogeneity was high across studies (I²=84.0%, Ï?² p<0.001). Twelve studies (5,186 individuals) commenced follow-up before broad-access to DAAs, with a pooled incidence of 1.27/100py (95% CI, 0.69-1.86; I²=81.8%, Ï?²p=0.187) and five studies (13,177 individuals) started follow-up after broad-access to DAAs, with a pooled incidence of 0.30/100py (95% CI, 0.11-0.50; I²=33.2%, Ï?²p=0.187).
CONCLUSIONS: Our pooled estimates of HCV incidence among PrEP users were lower than reported in a previous meta-analysis (1.48/00py), and lower in settings where broad access to DAAs had occurred prior to study initiation. Findings suggest that reductions in community-level HCV viremia driven by DAA uptake among respective GBM populations, which occurred prior to changes in sexual networks and behaviours associated with PrEP uptake, may have contributed to lower HCV transmission among PrEP users.

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