Pathophysiology
Clinical meaning
Hepatitis is inflammation of the liver, most commonly caused by viral infections (hepatitis A through E), though it can also result from alcohol, drugs, autoimmune conditions, and metabolic diseases. Understanding the five major hepatitis viruses, their transmission routes, and clinical courses is essential for nursing practice and infection prevention. Hepatitis A virus (HAV) is an RNA virus transmitted via the fecal-oral route (contaminated food, water, or close personal contact). It causes acute hepatitis only, never progresses to chronic infection, and confers lifelong immunity after recovery. The incubation period is 15-50 days. HAV is common in areas with poor sanitation and is the most common cause of acute viral hepatitis worldwide. It is typically self-limiting with full recovery in 2-6 months. Rarely, it can cause fulminant hepatic failure, particularly in older adults and those with pre-existing liver disease. Hepatitis B virus (HBV) is a DNA virus transmitted through blood and body fluids (sexual contact, percutaneous exposure, perinatal transmission from mother to infant). The incubation period is 45-180 days. HBV can cause both acute and chronic infection. In adults, 90-95% clear acute...