Molecular analysis of hepatitis C virus infection in Bulgarian injecting drug users.

Intravenous drug users constitute a group at risk for hepatitis C virus (HCV) infection. Today, no data are available on the molecular epidemiology of HCV in Bulgaria despite the fact that in recent years the incidence of acute hepatitis C infection among Bulgarian intravenous drug users increased sixfold and about 2/3 of them developed a chronic infection. The aim of this study was to determine the circulation of hepatitis C genotypes among drug users and to study the evolution and transmission history of the virus by molecular clock and Bayesian methods, respectively.

HIV-1 subtype C transmission network: the phylogenetic reconstruction strongly supports the epidemiological data.

The sequence and times of the transmission events was reported after a hospital accident by a phylodynamic reconstruction of transmission network among four subjects. The dated tree allowed to date the transmission events with good approximation, the time point and direction of each transmission, estimated on the basis of the phylogeny, and agreed with the presumptive time of infection on the basis of clinical history-taking.