Viral hepatitis type A and E

Infections with hepatitis A (HAV) and E viruses (HEV) represent important differential diagnoses of acute viral hepatitis. Both viruses are primarily transmitted via the fecal-oral route. A vaccine is so far only approved for HAV infections in Germany. The nationwide incidence in 2011 was 1 (HAV) and 0.3 (HEV) cases of the disease per 100,000 inhabitants although in recent years there has been a substantial increase in HEV infections. Both infections present clinically as acute and self-limiting hepatitis. Fulminant courses are rare and HAV infections are mostly associated with advanced age or preexisting liver disease and HEV infections are additionally associated with the second or third trimester of pregnancy. In immunosuppressed patients an HEV infection can become chronic while no chronic cases have been described for HAV infections. The diagnosis is based on the detection of HAV and HEV-specific antibodies as well as detection of HEV RNA. A specific therapy for acute HAV and HEV infections does not exist but a supportive therapy is normally sufficient. Fulminant and chronic HEV infections can be treated with ribavirin. In extremely rare cases a fulminant course can lead to liver failure and in this case liver transplantation represents the only therapy option.