HCV Direct-Acting Antiviral (DAA) treatment uptake has drastically increased in HIV-HCV coinfected patients in France, resulting in HCV cure in more than half of patients at the end of 2015. We used model projections to estimate the impact of DAAs on HIV-HCV epidemiology over the next decade.
The model was based on epidemiological data from the French DatAIDS cohort. Eight risk groups were considered: high-risk (HR) and low-risk (LR) MSM and males/females heterosexuals, IVDU or patients with other risk. To model HIV-HCV epidemiology we used a mathematical compartmental deterministic model calibrated using the 2012-2015 observed incidence, prevalence and treatment coverage. Figures of the undiagnosed HIV-HCV epidemic were estimated from a previously published model (Supervie AIDS 2014). The impact of scaling-up DAA on HCV prevalence was investigated across the different risk groups.
On January 1st, 2016, 156,811 patients were estimated to be infected with HIV in France (under care: 131,861) of whom 7,939 (5.1%) had an active HCV infection with a detectable serum RNA (under care: 7,216 (5.5%)). Assuming a treatment coverage (TC) of 30%/year (observed rate in 2015), active HCV prevalence among patients under care dropped to 1.31% in 2021 and to 0.55% in 2026. Sub-analyses showed similar results in most risk groups, including LR MSM. Due to higher acute infection and reinfection rates, the predicted prevalence in HR MSM increased from 2.39% in 2016 to 2.46% in 2021 and 3.96% in 2026. Increasing TC in HR MSM to 50/70% per year decreased the prevalence in this group to 1.10/0.50% in 2021 and to 0.86/0.19% in 2026. With the current TC of 30%, the mean delay to reach <50 active infections per group was 10.5 years for every risk group except HR MSM. This threshold was reached at 5.5 years in HR MSM only when increasing TC to 70% in this group. At 30% TC, undiagnosed patients will account for 26.4% of patients with active HCV infection in 2021 and for 43.3% in 2026.
Our model suggests that DAA based treatments could nearly eradicate HIV-HCV coinfection in France within 10 years in most of the risk groups, including LR MSM. Consequently acute infections and reinfections in HR MSM and undiagnosed HIV-infected patients will account for the majority of infections in the future. Eradication in these 2 groups will require increased treatment coverage of acute infections in HR MSM and increased engagement in care for undiagnosed infections.