What Is Hepatitis A IgM?

Hepatitis A is caused by the hepatitis A virus (HAV), which is mainly transmitted through the fecal-oral route, and the source of infection is mostly patients. The incubation period of hepatitis A is 15 to 45 days, and the virus usually exists in the blood and feces of patients 5 to 6 days before the elevation of transamination. Two to three weeks after the onset, with the production of specific antibodies in the serum, the infectivity of blood and feces gradually disappeared. The body can produce antibodies during a dominant or recessive infection of hepatitis A. There are two types of antibodies (anti-HAV) in serum, namely anti-HAVIgM and anti-HAVIgG. Anti-HAVIgM appears early, can be detected within a few days after the onset, and the jaundice peaks, which is an important indicator for early diagnosis of hepatitis A. Anti-HAVIgG appears late and lasts a long time. It is usually negative in the early stage of infection. Anti-HAVIgG positive indicates that it has been infected with HAV. At present, the microbiological examination of hepatitis A mainly focuses on the antigens and antibodies of hepatitis A virus. Applied methods include immunoelectron microscopy, complement binding test, immunoadhesion hemagglutination test, solid-phase radioimmunoassay and enzyme-linked immunosorbent assay, polymerase chain reaction, and cDNA-RNA molecular hybridization technology.