The Hepatits A virus (HAV) is the most frequent cause for hepatitis worldwide. The course of the infection is quite different depending on the individual. In infants the infection is often asymptomatic and results in lifelong immunity. Also in adults HAV-infections can go along with mild symptoms. In general the severness of the infections increases with increasing age, up to a mortality of 2%. First symptoms are abnormal fatigue, indisposition, fever, vomitting followed by an increase of aminotransferase activity, dark urine and jaundice.
HAV is transmitted fecal-oral directly by personal contact or indirect by contaminated water or food.
HAV is the only hepatovirus which is member of the family of the picornaviridae. It is a non-coated particle of about 27 nm with an icosahedric capsid. The capsid contains a 7,5kbp long single-stranded RNA of positive orientation. This RNA codes for a polyprotein which is posttranslational processed by proteolytical cleavage. Through this cleavage the single viral structure and non-structure proteins are formed.
A HAV infection is detected by the measurement of HAV-specific IgM antibodies in serum or by the detection of antigen in feces and/or serum by ELISA. HAV-RNA is detected by reverse transcription and polymerase chain reaction (RT-PCR) in feces or serum. The measurement of IgG antibodies in serum proves a previous infection or an immunreaction after vaccination.
Mediagnost offers test systems for the detection of anti HAV-IgM and total antibodies, the HAV antigen and HAV-RNA.