- hepatitis B
- hepatitis B -'bē n a sometimes fatal hepatitis caused by a double-stranded DNA virus (species Hepatitis B virus of the genus Orthohepadnavirus, family Hepadnaviridae) that tends to persist in the blood serum and is transmitted esp. by contact with infected blood (as by transfusion or by sharing contaminated needles in illicit intravenous drug use) or by contact with other infected bodily fluids (as semen) called also serum hepatitis
* * *a viral disease caused by the hepatitis B virus; it is endemic worldwide, with the areas of highest endemicity being China, Southeast Asia, sub-Saharan Africa, most Pacific islands, and the Amazon basin. The virus is shed in all body fluids by individuals with acute or chronic infections and by asymptomatic carriers, and is transmitted primarily by parenteral routes, such as by blood transfusion or by sharing of needles among drug users. Oral transmission can occur but has low efficiency; the disease can also be spread by intimate contact (such as sexual contact), as well as by vertical transmission from mother to neonate. The incubation period is about 90 days (range, 40 to 180 days), and the clinical course is more variable than that of hepatitis A. In the prodromal phase there may be fever, malaise, anorexia, nausea, and vomiting (which decline with the onset of clinical jaundice), as well as urticaria, angioedema, arthritis, and occasionally glomerulonephritis or a serum sicknessâ€“like syndrome. Most patients recover completely and become HBSAg-negative in 3 to 4 months, but some remain chronic carriers or develop chronic active hepatitis or chronic persistent hepatitis. Massive hepatic necrosis (fulminant hepatitis) is a rare complication. In areas of high endemicity a relationship has been shown between hepatitis and virus infection, cirrhosis, and hepatocellular carcinoma. Formerly called inoculation or serum h. See also under antigen.
Medical dictionary. 2011.