Fig. 3
From: Hepatitis D: challenges in the estimation of true prevalence and laboratory diagnosis
Serological patterns of HDV infection. A Coinfection is the simultaneous acute infection of HBV and HDV in a susceptible individual. Serum HDAg is detectable only transiently in blood specimens collected early at the onset of HDV, before the rising of antibodies. Anti-HDV IgM response is rapid and weak suggesting a resolution of infection. Anti-HDV IgG levels increased rapidly and persisted. B Superinfection is an HDV infection in an individual chronically infected with HBV. This pattern of infection has two components, the acute stage and the chronic stage. The acute phase is characterized by very high levels of HDV viremia and HDAg antigen in serum/liver. In the chronic period, HDV RNA, anti-HDV IgM and anti-HDV IgG persist. HDAg can be detected by liver biopsy. HDV hepatitis D virus; HBV hepatitis B virus; HDAg hepatitis D antigen; HBsAg hepatitis B surface antigen; Anti-HDV IgM immunoglobulin M antibody to the HDAg; Anti-HDV IgG immunoglobulin G antibody to the HDAg