Hepatitis A: Detection by Immune Electron Microscopy of a Viruslike Antigen Associated with Acute Illness

Abstract
Spherical 27-nanometer particles were visualized in stools obtained from hepatitis A patients in the acute phase of the disease. The particle was serologically specific for this disease, and every hepatitis A patient tested demonstrated a serologic response to this antigen. The findings suggest that it is the etiologic agent of hepatitis A.