Transmission electron micrograph (TEM) revealed the presence of hepatitis B virions. The large round virions are known as Dane particles. Hepatitis means inflammation of the liver. Toxins, certain drugs, some diseases, heavy alcohol use, and bacterial and viral infections can all cause hepatitis. Hepatitis is also the name of a family of viral infections that affect the liver; the most common types in the United States are hepatitis A, hepatitis B, and hepatitis C. Hepatitis B is caused by infection with the Hepatitis B virus (HBV). The incubation period from the time of exposure to onset of symptoms is 6 weeks to 6 months. HBV is found in highest concentrations in blood and in lower concentrations in other body fluids (e.g., semen, vaginal secretions, and wound exudates). HBV infection can be self-limited or chronic. Cropped image.