Parameter prior and posterior distributions.
Prior distributions are in grey and posterior distributions inferred by ABC are in red. The thinner the posterior distribution width, the more precise the inference. Posterior distributions are truncated based on the prior distribution. The parameters γ1 and γ2 are the end of infectiousness rates for non-MSM and MSM hosts respectively. The parameters a1 and a2 are the assortativity levels between hosts types, for non-MSM and MSM hosts respectively. ν is the transmission rate differential between non-MSM and MSM hosts. The parameters and are respectively the reproduction numbers for the non-MSM hosts before and after the introduction of the third-generation HCV tests in 1997. The t0 parameter is the origin of the epidemic in non-MSM hosts, and t2 is the origin of the epidemic in MSM hosts.