hepatitis(redirected from amebic hepatitis)
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hepatitis (hĕpˌətīˈtĭs), inflammation of the liver. There are many types of hepatitis. Causes include viruses, toxic chemicals, alcohol consumption, parasites and bacteria, and certain drugs. Symptoms of hepatitis are nausea, fever, weakness, loss of appetite, sudden distaste for tobacco smoking, and jaundice.
A number of viruses can cause acute viral hepatitis. Five have been identified and named hepatitis A through E. At least 10 other viruses are under study. Hepatitis A, also called infectious hepatitis, occurs sporadically or in epidemics, the virus being present in feces and transmittable via contaminated food (e.g., food prepared by an infected person with unwashed hands or fresh food washed or grown with contaminated water) or water. A person with active infection can spread it by physical contact. The disease usually resolves on its own. Exposed persons can be protected by injections of gamma globulin. A vaccine was made available in 1995 and is recommended for children at risk for the virus.
Hepatitis B, also called serum hepatitis, was commonly transmitted through blood transfusions until the 1970s, when screening tests were introduced. Intravenous-drug abusers remain a high-risk group because of the sharing of needles. It is also spread by sexual transmission and from mother to baby at birth. Some infected individuals, particularly children, become chronic carriers of the virus. Hepatitis B can progress to chronic liver disease and is associated with an increased risk of developing liver cancer. A vaccine, available since 1981, is recommended for all infants and others at risk for the virus. Alpha-interferon was approved as a treatment in 1992.
Hepatitis C, formerly called non-A, non-B hepatitis, is also transmitted by contaminated blood transfusions and by sharing of needles among drug abusers, although in many cases no source can be identified. It is the most common form of chronic liver disease in the United States. Many of those infected have no symptoms but become carriers. The virus can cause serious liver damage and is the leading cause of liver transplants in the United States. Blood banks routinely screen for hepatitis C. Depending on the genetic makeup of the virus, antivirals, either alone or in conjunction with alpha-interferon and the drug ribavirin, are used to treat the disease, and may result in a long-term cure.
Hepatitis D, or delta hepatitis, affects only people with hepatitis B; those infected with both viruses tend to have more severe symptoms. Hepatitis E is spread by consuming feces-contaminated food or water. It is common in Mexico, Africa, and Asia and is especially serious in pregnant women.
Hepatitis can be incurred as a complication of several other disorders in addition to viral infection, among them amebic dysentery, cirrhosis of the liver, and mononucleosis. Also, alcohol, carbon tetrachloride, some tranquilizers and antibiotics, and many other substances can produce a toxic reaction in the liver, resulting in toxic hepatitis.
An inflammation of the liver caused by a number of etiologic agents, including viruses, bacteria, fungi, parasites, drugs, and chemicals. The most common infectious hepatitis is of viral etiology. All types of hepatitis are characterized by distortion of the normal hepatic lobular architecture due to varying degrees of necrosis of individual liver cells or groups of liver cells, acute and chronic inflammation, and Kupffer cell enlargement and proliferation. There is usually some degree of disruption of normal bile flow, which causes jaundice. The severity of the disease is highly variable and often unpredictable. See Liver
A frequently occurring form of hepatitis is caused by excessive ethyl alcohol intake and is referred to as alcoholic hepatitis. It usually occurs in chronic alcoholics and is characterized by fever, high white blood cell count, and jaundice. Some drugs are capable of damaging the liver and can occasionally cause enough damage to produce clinical signs and symptoms. Among these drugs are tetracycline, methotrexate, anabolic and contraceptive steroids, phenacetin, halothane, chlorpromazine, and phenylbutazone.
Clinical features of hepatitis include malaise, fever, jaundice, and serum chemical tests revealing evidence of abnormal liver function. In most mild cases of hepatitis, treatment consists of bedrest and analgesic drugs. In those individuals who develop a great deal of liver cell necrosis and subsequently progress into a condition known as hepatic encephalopathy, exchange blood transfusions are often used. This is done with the hope of removing or diluting the toxic chemicals thought to be the cause of this condition. Chronic hepatitis is a condition defined clinically by evidence of liver disease for at least 6 consecutive months.
Hepatitis C is a disease of the liver caused by the hepatitis C virus (HCV). The prevalence of HCV infection worldwide is 3% (170 million people), with infection rates in North America ranging from 1 to 2% of the population. A simulation analysis estimated that in the period from 1998 to 2008 there will be an increase of 92% in the incidence of cirrhosis of the liver, resulting in a 126% increase in the incidence of liver, failures and a 102% increase in the incidence of hepatocellular carcinoma (HCC), all attributed to HCV.
Hepatitis C virus can be transmitted only by blood-to-blood contact. With the institution of screening of blood, intravenous drug use has become the major source of transmission in North America. Approximately 89% of people who use intravenous drugs for one year become infected with HCV.
Management strategies can be divided into three main areas: surveillance of patients with chronic HCV infection who have not developed cirrhosis; surveillance of patients with established cirrhosis; and strategies to eradicate HCV.
the general name for inflammatory diseases of the liver that have various causes and treatments. Depending on its cause, hepatitis is classified as primary infectious hepatitis or secondary infectious hepatitis, which accompanies some infectious diseases (for example, infectious mononucleosis, brucellosis, malaria, and syphilis). Hepatitis can also be caused by microbial toxins entering the liver from the intestine or by poisoning with arsenic, mushrooms (death-cup and fly agaric), and some everyday and industrial poisons, including alcohol, trinitrotoluene, dinitrophenol, and dichloroethane. Hepatitis can also occur in cases of pregnancy toxicoses.
There are acute and chronic forms of hepatitis. The principal symptom of acute hepatitis is jaundice, which is accompanied by enlargement of the liver and pain in the hypochondriac region. Chronic hepatitis may result from acute infectious (viral) hepatitis, infectious mononucleosis, bacterial infections (tuberculosis and brucellosis), parasitic diseases (for example, opisthorchiasis and clonorchiasis), chronic poisoning by various toxic agents, and improper use of certain drugs. Chronic hepatitis is sometimes of toxic-allergic origin, when complex immunologic disturbances arise from individual intolerance of drugs or chemical agents or as a consequence of such allergic diseases as systematic lupus erythematosus, periarteritis nodosa, scleroderma, and dermatomyositis. The development of chronic hepatitis is promoted by metabolic disorders, a poor diet deficient in proteins, and alcoholism. In a prolonged course of inflammation of the liver, functional (hepatic) cells die, and in their place connective (fibrous) tissue develops. Chronic hepatitis with more severe liver lesions (for example, in alcoholism) may lead to the development of cirrhosis of the liver. Depending on the extent of damage to the liver, patients may develop digestive disorders, malaise, elevated temperature in some cases, enlargement of the liver and, less commonly, of the spleen, and sometimes jaundice of the skin and mucous membranes, often with pain in the right hypochondraic region. Chronic hepatitis may persist for years. Prompt and correct treatment and appropriate work and living arrangements result in complete recovery.
Treatment involves elimination of the main causes of the disease. Preventive measures include eradication of infectious diseases, especially epidemic (infectious) hepatitis. Prevention of imported infections (for example, malaria and relapsing fever), amebiosis, and helminthiases is important in fighting hepatitis. Other measures include elimination of occupational, everyday, and food poisonings and adequate nutrition and regimen. Patients with exacerbated cases of hepatitis should be promptly hospitalized, and there should be clinical follow-up on patients.
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Bondar’, Z. A. Klinicheskaia gepatologiia. Moscow, 1970.
Z. A. BONDAR’