Hepatitis E: clinical presentation in disease-endemic areas and diagnosis

Infection with hepatitis E virus (HEV), mostly genotype 1, is endemic in several developing countries. It can be asymptomatic, be associated with acute hepatitis or fulminant hepatic failure, or present as acute-on-chronic liver disease. Pregnant women are at particular risk of serious outcomes and death. Chronic HEV infection has not been reported from these areas. Diagnosis of acute hepatitis E depends on detection of IgM anti-HEV antibodies or HEV RNA. Current assays for IgM anti-HEV are suboptimal, with high rates of interassay discordance. Though they perform reasonably well in disease-endemic areas, positive test results in low-endemicity areas require confirmation using HEV RNA testing. Detection of IgG anti-HEV antibodies indicates exposure to HEV, either recent or remote. Assays for these too have low concordance, making comparisons of seroprevalence rates using different assays difficult to interpret. There is an urgent need to develop better assays for markers of HEV infection and exposure.