Epidemiology and genetic characterization of hepatitis A virus genotype IIA.

Three hepatitis A virus (HAV) genotypes, I, II, and III, divided into subtypes A and B, infect humans. Genotype I is the most frequently reported, while genotype II is hardly ever isolated, and its genetic diversity is unknown. From 2002 to 2007, a French epidemiological survey of HAV identified 6 IIA isolates, mostly from patients who did not travel abroad.

Viral and clinical factors associated with surface gene variants among hepatitis B virus carriers.

Background: Understanding the prevalence of potential antigenic variation of the hepatitis B virus (HBV) surface antigen (HBsAg) is fundamental for assay design and to future changes in vaccine formulation. In this study, the nature and frequency of HBsAg polymorphisms occurring in France in chronic carriers and in newly diagnosed patients were determined. We focused on variations in the major hydrophilic region (MHR), the central core of HBsAg known to be exposed on the surface and involved in antibody binding.