- hepatitis
- Inflammation of the liver, due usually to viral infection but sometimes to toxic agents. [hepat- + -itis] Previously endemic throughout much of the developing world, viral h. now ranks as a major public health problem in industrialized nations. The 3 most common types of viral h. (A, B, and C) afflict millions worldwide. Acute viral h. is characterized by varying degrees of fever, malaise, weakness, anorexia, nausea, and abdominal distress. Hepatocellular damage causes bilirubin retention, often with jaundice, and a rise in serum levels of certain enzymes (particularly transaminases). H. A, caused by an enterovirus, is spread by the fecal-oral route, most often through ingestion of contaminated food or water. The case fatality rate is less than 1%, and recovery is complete. The presence of antibody to h. A virus indicates prior infection, noninfectivity, and immunity to future attacks. H. B, due to a small DNA virus, is transmitted through sexual contact, sharing of needles by IV drug abusers, needlestick injuries among health care workers, and from mother to fetus. The annual incidence in the U.S. is 300,000 cases. The incubation period is 6–24 weeks. Some patients become carriers, and in some an immune response to the virus induces a chronic phase leading to cirrhosis, hepatic failure, and risk of hepatocellular carcinoma. H. B surface antigen (HBsAg) is detectable early in serum; its persistence correlates with chronic infection and infectivity. Core antigen (HBcAg) appears later and also indicates infectivity. H. C is the principal form of transfusion-induced h.; a chronic active form often develops. Acute infection with h. B or C has a higher mortality rate than h. A. Effective vaccines are available for active immunization against h. A and h. B. Interferon-alpha brings about clinical remission in some cases of h. B and h. C. H. D is due to an RNA virus capable of causing disease only in persons previously infected with h. B. H. E, which occurs chiefly in the tropics, resembles h. A in that it is transmitted by the fecal-oral route and does not become chronic or lead to a carrier state, but it has a much higher mortality rate.- anicteric virus h. a relatively mild h., without jaundice, due to a virus; the principal physical signs and symptoms are enlargement of the liver, lymph node s, and often the spleen, together with headache, continuous fatigue, nausea, anorexia, sudden distaste for smoking, abdominal pains, and sometimes mild fever; laboratory tests reveal evidence of h..- cholangiolitic h. h. with inflammatory changes around small bile ducts, producing mainly obstructive jaundice; may be due to viral or bacterial infection ascending biliary tree because of obstruction.- cholestatic h. jaundice with bile stasis in inflamed intrahepatic bile ducts; usually due to toxic effects of a drug.- chronic h. any of several types of h. persisting for more than six months, often progressing to cirrhosis. SYN: chronic active liver disease.- chronic active h. h. with chronic portal inflammation that extends into the parenchyma, with piecemeal necrosis and fibrosis which usually progresses to a coarsely nodular postnecrotic cirrhosis. SYN: juvenile cirrhosis, posthepatitic cirrhosis, subacute h..- chronic persisting h. a form of chronic h. that is usually benign, not progressing to cirrhosis, and usually asymptomatic without physical findings but with continuing abnormalities of tests of liver status. SYN: chronic persistent h..- h. externa SYN: perihepatitis.- fulminant h. severe, rapidly progressive loss of hepatic function due to viral infection or other cause of inflammatory destruction of liver tissue.- halothane h. hepatocellular damage said to result from the administration of halothane anesthesia.- long incubation h. outdated name for h. B based on the longer incubation period (range 30–180 days, usually 60–90) compared with h. A (15–45 days, mean 30).- lupoid h. jaundice with evidence of liver cell damage and positive antinuclear antibody or LE cell tests, but without evidence of systemic lupus erythematosus; liver biopsies usually show chronic active h. with infiltration by plasma cells, or postnecrotic cirrhosis; serum is negative for h. B antigen. SYN: plasma cell h..- NANB h. SYN: non-A, non-B h..- NANBNC h. abbreviation for non-A, non-B, non-C h..- neonatal h. h. in the neonatal period presumed to be due to any of a variety of causes, chiefly viral; characterized by direct and indirect bilirubinemia, hepatocellular degeneration, and appearance of multinucleated giant cells; may be difficult to distinguish from biliary atresia, but is more likely to end with recovery, although cirrhosis may develop. SYN: giant cell h..- non-A, non-B h. h. caused by any number of infectious agents not detectable by methods that reveal the presence of h. viruses A and B. SYN: NANB h..- non-A, non-B, non-C h. (NANBNC h.) h. caused by viral organisms other than h. viruses A, B, or C.- peliosis h. a rare condition in which the liver contains very numerous small blood-filled spaces, sometimes lined with endothelium; it may be found incidentally or rupture may cause intraperitoneal hemorrhage.- viral h. 1. h. caused by any one of at least 7 immunologically unrelated viruses: h. A virus, h. B virus, h. C virus, h. D virus, h. E virus, h. F virus, h. G virus; 2. h. caused by a viral infection, including that by Epstein-Barr virus and cytomegalovirus. SYN: virus h..- viral h. type A a virus disease with a short incubation period (usually 15–50 days), caused by h. A virus, a member of the family Picornaviridae, often transmitted by fecal-oral route; may be inapparent, mild, severe, or occasionally fatal and occurs sporadically or in epidemics, commonly in school-age children and young adults; necrosis of periportal liver cells with lymphocytic and plasma cell infiltration is characteristic and jaundice is a common symptom. SYN: epidemic h., h. A, infectious h., MS-1 h., short incubation h., virus A h..- viral h. type B a virus disease with a long incubation period (usually 50–160 days), caused by a h. B virus, a DNA virus and member of the family Hepadnaviridae, usually transmitted by injection of infected blood or blood derivatives or by use of contaminated needles, lancets, or other instruments; clinically and pathologically similar to viral h. type A, but there is no cross-protective immunity; HBsAg is found in the serum and the h. delta virus occurs in some patients. SYN: h. B, serum h., transfusion h., virus B h..- viral h. type C (NANB); principal cause of non-A, non-B posttransfusion h. caused by an RNA virus that is classified with the Flaviviridae family. The incubation period is 6–8 weeks with about 75% of infections subclinical and giving rise to chronic persistent infection. A high percentage of these develop chronic liver disease leading to cirrhosis and possible hepatocellular carcinoma. SYN: h. C, virus C h..- viral h. type D acute or chronic h. caused by a satellite virus, the h. deltavirus, a defective RNA virus requiring HBV for replication since it uses HBsAg as its own coat. The acute type occurs in two forms: 1) coinfection, the simultaneous occurrence of h. B virus and h. delta virus infections, which usually is self-limiting; 2) superinfection, the appearance of h. delta virus infection in a h. B virus carrier, which often leads to chronic h. The chronic type appears to be more severe than other types of viral h.. SYN: delta h., h. D.- viral h. type E h. caused by a nonenveloped, single-stranded, positive-sense RNA virus 27–34 nm in diameter, unrelated to other h. and belonging to the family Caliciviridae; it is the principal cause of enterically transmitted, waterborne, epidemic NANB h. occurring primarily in Asia, Africa and South America. SYN: h. E.
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1) inflammation of the liver2) a disease or condition (as hepatitis A or hepatitis B) marked by inflammation of the liverhep·a·tit·ic -'tit-ik adj* * *
n.inflammation of the liver caused by viruses, toxic substances, or immunological abnormalities. Infectious hepatitis is caused by viruses, several types of which have been isolated as specific causes of the disease and can be detected by blood tests, including hepatitis A, hepatitis B, hepatitis C, hepatitis D, and hepatitis E. Other viral causes of hepatitis include the Epstein-Barr virus. See also Entamoeba.Hepatitis A (epidemic hepatitis) is transmitted by food or drink contaminated by a carrier or patient and commonly occurs where sanitation is poor. After an incubation period of 15-40 days, the patient develops fever and sickness. Yellow discoloration of the skin (see jaundice) appears about a week later and persists for up to three weeks. The patient may be infectious throughout this period. Serious complications are unusual and an attack often confers immunity. Injection of gammaglobulin provides temporary protection, but active immunization is preferable.Hepatitis B (formerly known as serum hepatitis) is transmitted by infected blood or blood products contaminating hypodermic needles, blood transfusions, or tattooing needles, by sexual contact, or by contact with any other body fluid (e.g. milk, sweat); it often occurs in drug addicts. Symptoms, which develop suddenly after an incubation period of 1-6 months, include headache, fever, chills, general weakness, and jaundice. Most patients make a gradual recovery but the mortality rate is 5-20%. A vaccine is available.Hepatitis C (formerly known as non-A, non-B hepatitis) has a mode of transmission similar to that of hepatitis B; symptoms include fatigue, sore bones, and dryness of the eyes. Hepatitis D is a defective virus and occurs only with or after infection with hepatitis B. Patients with D virus usually have severe chronic hepatitis. Hepatitis E is transmitted by infected food or drink and can cause acute hepatitis.Chronic hepatitis continues for months or years, eventually leading to cirrhosis (see also hepatoma). It may be caused by persistent infection with a hepatitis virus (usually hepatitis B, C, or D), which may respond to treatment with interferon, or by autoimmune disease, treated by corticosteroid or immunosuppressant therapy.* * *
hep·a·ti·tis (hep″ə-tiґtis) pl. hepatiґtides [hepat- + -itis] inflammation of the liver.
Medical dictionary. 2011.
