title: Hepatitis A.
abstract: Hepatitis A is a disease of worldwide distribution which occurs in endemic and epidemic form and is transmitted primarily by person-to-person contact through the fecal-oral route. Common source epidemics due to contamination of food are relatively common, and water-borne epidemics have been described less frequently. The presumed etiologic agent of hepatitis A has now been visualized by immune electron microscopic (IEM) techniques in early acute-illness-phase stools of humans with hepatitis A as well as in chimpanzees experimentally infected with material known to contain hepatitis A virus. In addition, several new serologic tests for the detection of antibody against hepatitis A virus have been described. These include complement fixation and immune adherence techniques. Current data suggest that hepatitis A is caused by a single viral agent lacking the morphologic heterogeneity of hepatitis B viral components and that there may be relative antigenic homogeneity between strains of virus recovered from various parts of the world. Serologic studies to date also indicate that hepatitis A virus is not a major contributing cause in post-transfusion hepatitis.
mesh_terms: D000293:Adolescent; D000818:Animals; D000914:Antibodies, Viral / Q000032:analysis; D000917:Antibody Formation; D002648:Child; D003168:Complement Fixation Tests; D000882:Haplorhini; D006506:Hepatitis A / Q000453:epidemiology / Q000276:immunology*; D006507:Hepatovirus / Q000276:immunology / Q000302:isolation & purification; D006801:Humans; D007104:Immune Adherence Reaction; D008297:Male; D008887:Military Medicine; D014481:United States
chemical_list: D000914:Antibodies, Viral