Dynamics and molecular evolution of HIV-1 strains in Sicily among antiretroviral naïve patients

► We examine changes in the molecular epidemiology of HIV-1 strains in Sicily. ► Heterosexual contacts are responsible for the most part of HIV-1 non-B infections. ► In Sicily, HIV-1 epidemic is still mostly attributable to the B subtype. ► HIV-1 eterogeneity is mainly correlated to population movements and immigration influx. ► An increasing genetic diversity has been observed in the autochthonous population.