Acute Although a number of viruses affect the liver, i.... hepat acut

Acute Although a number of viruses affect the liver, including and Epstein-Barr virus, which causes , there are three distinctive transmissible viruses that are specifically known to cause acute damage to liver cells: hepatitis A virus (HAV), hepatitis B virus (HBV), and hepatitis C virus (HCV). Many newly infected persons develop the acute disease within three weeks to six months after exposure, while some develop an asymptomatic form of hepatitis that may appear only as chronic disease years later. There are two methods of preventing hepatitis B: , through the use of a specific immunoglobulin derived from patients who have successfully overcome an acute HBV infection; and , through the injection of noninfective, purified HBV surface antigen. The average incubation period of the disease is about seven weeks, and an acute attack of hepatitis C is usually less severe than acute hepatitis B. Hepatitis C, however, is more likely to become chronic than is hepatitis B, and it may! recur episodically with acute flares. A small percentage of patients, especially those with HBV infections, may develop , painful skin nodules, acute , or urinary bleeding caused by the deposition of large immune antigen-antibody complexes in the small blood vessels of adjacent organs. After the phase of jaundice subsides, almost all patients with hepatitis A, and at least 90 percent of those with hepatitis B, recover completely. Aside from jaundice, the physical examination of patients with acute viral hepatitis may reveal nothing more than a detectable enlargement and, at times, tenderness of the liver. A small number, perhaps 1 percent, of patients with viral hepatitis, especially the elderly, develop a sudden, severe ( ) form of hepatic necrosis that can lead to death. hepat acut