Epidemiologia e filodinamica dei genotipi e sottogenotipi di HBV più diffusi in Italia e in Albania

The molecular epidemiology and phylodynamic history of HBV in Italy and Albania was studied on 230 Italian isolates drawn during the period 1980-2007 and 73 Albanian isolates drawn between 2005-2007 from patients living in a homogenous geographical area. Evolutionary rates were estimated and HBV demographic history was reconstructed by using a statistical approach based on coalescent theory. In Italy, the predominant genotype resulted was D (72%) followed by genotype A (20%), F and G (3%) both; among the subgenotypes, D3 was predominant in intravenous drug users (IVDUs) and A2 in men-having-sex-with-men (MSM). In Albania, the only genotype resulted was D, the predominant subgenotypes were D2 (72%), followed by D1 and D3 (14%) both. The evolutionary rates in Albanian D2 and Italian D3 subgenotype were equal. In Italy, the diffusion of D3 subgenotype was identified between 1950 and 1980 probably by use of non safely blood transfusions. In Albania, the entry and diffusion of D2 subgenotype was identified between 1986 and 1995 probably by parenteral transmission of the HBV. The exponential growth rate of D3 epidemic in Italy was significantly lower than that of D2 in Albania.