| 释义 |
hepatitis B
hepatitis Bn. A viral hepatitis that is either acute or chronic, caused by a DNA virus, and usually transmitted by infected blood products (as through transfusion), contaminated needles, or exposure to infected bodily fluids through sexual intercourse. It can cause chronic liver damage and cancer. Also called serum hepatitis.hepatitis B n (Pathology) a form of hepatitis caused by a virus transmitted by infected blood (as in transfusions), contaminated hypodermic needles, sexual contact, or by contact with any other body fluid. Former name: serum hepatitis hepatitis B
n. a form of hepatitis caused by a DNA virus (hepatitis B virus) that persists in the blood and has a long incubation period: usu. transmitted by sexual contact or by injection or ingestion of infected blood or other bodily fluids. Also called serum hepatitis. hepatitis BInflammation of the liver caused by infection with the hepatitis B virus carried by the blood.Thesaurus| Noun | 1. | hepatitis B - an acute (sometimes fatal) form of viral hepatitis caused by a DNA virus that tends to persist in the blood serum and is transmitted by sexual contact or by transfusion or by ingestion of contaminated blood or other bodily fluidsserum hepatitisviral hepatitis - hepatitis caused by a virus |
TranslationsEncyclopediaSeeHBhepatitis B
Hepatitis B DefinitionHepatitis B is a potentially serious form of liver inflammation due to infection by the hepatitis B virus (HBV). It occurs in both rapidly developing (acute) and long-lasting (chronic) forms, and is one of the most common chronic infectious diseases worldwide. An effective vaccine is available that will prevent the disease in those who are later exposed.DescriptionCommonly called "serum hepatitis," hepatitis B ranges from mild to severe. Some people who are infected by HBV develop no symptoms and are totally unaware of the fact, but they may carry HBV in their blood and pass the infection on to others. In its chronic form, HBV infection may destroy the liver through a scarring process, called cirrhosis, or it may lead to cancer of the liver.When a person is infected by HBV, the virus enters the bloodstream and body fluids, and is able to pass through tiny breaks in the skin, mouth, or the male or female genital area. There are several ways of getting the infection:- During birth, a mother with hepatitis B may pass HBV on to her infant.
- Contact with infected blood is a common means of transmitting hepatitis B. One way this may happen is by being stuck with a needle. Both health care workers and those who inject drugs into their veins are at risk in this way.
- Having sex with a person infected by HBV is an important risk factor (especially anal sex).
Although there are many ways of passing on HBV, the virus actually is not very easily transmitted. There is no need to worry that casual contact, such as shaking hands, will expose one to hepatitis B. There is no reason not to share a workplace or even a restroom with an infected person.More than 300 million persons throughout the world are infected by HBV. While most who become chronic carriers of the virus live in Asia and Africa, there are no fewer than 1.5 million carriers in the United States. Because carriers represent a constant threat of transmitting the infection, the risk of hepatitis B is always highest where there are many carriers. Such areas are said to be endemic for hepatitis B. When infants or young children living in an endemic area are infected, their chance of becoming a chronic hepatitis B carrier is at least 90%. This probably is because their bodies are not able to make the substances (antibodies) that destroy the virus. In contrast, no more than 5% of infected teenagers and adults develop chronic infection.Causes and symptomsWith the exception of HBV, all the common viruses that cause hepatitis are known as RNA viruses because they contain ribonucleic acid or RNA as their genetic material. HBV is the only deoxyribonucleic acid or DNA virus that is a major cause of hepatitis. HBV is made up of several fragments, called antigens, that stimulate the body's immune system to produce the antibodies that can neutralize or even destroy the infecting virus. It is, in fact, the immune reaction, not the virus, that seems to cause the liver inflammation.Acute hepatitis bIn the United States, a majority of acute HBV infections occur in teenagers and young adults. Half of these youth never develop symptoms, and only about 20%—or one in five infected patients—develop severe symptoms and yellowing of the skin (jaundice). Jaundice occurs when the infected liver is unable to get rid of certain colored substances, or pigments, as it normally does. The remaining 30% of patients have only "flu-like" symptoms and will probably not even be diagnosed as having hepatitis unless certain tests are done.The most commom symptoms of acute hepatitis B are loss of appetite, nausea, generally feeling poorly, and pain or tenderness in the right upper part of the abdomen (where the liver is located). Compared to patients with hepatitis A or C, those with HBV infection are less able to continue their usual activities and require more time resting in bed.Occasionally patients with HBV infection will develop joint swelling and pain (arthritis) as well as hives or a skin rash before jaundice appears. The joint symptoms usually last no longer than three to seven days.Typically the symptoms of acute hepatitis B do not persist longer than two or three months. If they continue for four months, the patient has an abnormally long-lasting acute infection. In a small number of patients—probably fewer than 3%—the infection keeps getting worse as the liver cells die off. Jaundice deepens, and patients may bleed easily when the levels of coagulation factors (normally made by the liver) decrease. Large amounts of fluid collect in the abdomen and beneath the skin (edema). The least common outcome of acute HBV infection, seen in fewer than 1% of patients, is fulminant hepatitis, when the liver fails entirely. Only about half of these patients can be expected to live.Chronic hepatitis bHBV infection lasting longer than six months is said to be chronic. After this time it is much less likely for the infection to disappear. Not all carriers of the virus develop chronic liver disease; in fact, a majority have no symptoms. But, about one in every four HBV carriers develop liver disease that gets worse over time, as the liver becomes more and more scarred and less able to carry out its normal functions. A badly scarred liver is called cirrhosis. Patients are likely to have an enlarged liver and spleen, as well as tiny clusters of abnormal blood vessels in the skin that resemble spiders.The most serious complication of chronic HBV infection is liver cancer. Worldwide this is the most common cancer to occur in men. Nevertheless, the overall chance that liver cancer will develop at any time in a patient's life is probably much lower than 10%. Patients with chronic hepatitis B who drink or smoke are more likely to develop liver cancer. It is not unusual for a person to simultaneously have both HBV infection and infection by HIV (human immunodeficiency virus, the cause of AIDS). A study released in 2003 reported that men infected with both HIV and HBV were more likely to die from liver disease than people infected with just one of the diseases.DiagnosisHepatitis B is diagnosed by detecting one of the viral antigens—called hepatitis B surface antigen (HBsAg)—in the blood. Later in the acute disease, HBsAg may no longer be present, in which case a test for antibodies to a different antigen—hepatitis B core antigen—is used. If HBsAg can be detected in the blood for longer than six months, chronic hepatitis B is diagnosed. A number of tests can be done to learn how well, or poorly, the liver is working. They include blood clotting tests and tests for enzymes that are found in abnormally high amounts when any form of hepatitis is present.TreatmentIn the past, there was no treatment available for hepatitis B. But developments have been made in recent years on drugs that suppress the virus and its symptoms. In early 2003, a drug called adefovir was reported as an effective treatment. Another drug called tenofovir was demonstrated as effective in patients infected with both hepatitis B and HIV. Two studies also reported on the effectiveness of a drug called Preveon, which was more expensive than others. Patients also should rest in bed as needed, continue to eat a healthy diet, and avoid alcohol. Any non-critical surgery should be postponed.PrognosisEach year an estimated 150,000 persons in the United States get hepatitis B. More than 10,000 will  Hepatitis B virus (HBV) is composed of an inner protein core and an outer protein capsule. The outer capsule contains the hepatitis B surface antigen (HBsAg). The inner core contains HBV core antigen (HBcAg) and hepatitis B e-antigen (HBeAg). This cell also contains polymerase, which catalyzes the formation of the cell's DNA. HBV is the only hepatitis-causing virus that has DNA, instead of RNA. (Illustration by Electronic Illustrators Group.)require hospital care, and as many as 5,000 will die from complications of the infection. About 90% of all those infected will have acute disease only. A large majority of these patients will recover within three months. It is the remaining 10%, with chronic infection, who account for most serious complications and deaths from HBV infection. In the United States, perhaps only 2% of all those who are infected will become chronically ill. The course of chronic HBV infection in any particular patient is unpredictable. Some patients who do well at first may later develop serious complications. Even when no symptoms of liver disease develop, chronic carriers remain a threat to others by serving as a source of infection.PreventionThe best way to prevent any form of viral hepatitis is to avoid contact with blood and other body fluids of infected individuals. The use of condoms during sex also is advisable.If a person is exposed to hepatitis B, a serum preparation containing a high level of antibody against HBV may prevent infection if given within three to seven days of exposure. Babies born of a mother with HBV should receive the vaccine within 24 hours. An effective and safe vaccine is available that reliably prevents hepatitis B. Vaccination is suggested for most infants and for children aged 10 and younger whose parents are from a place where hepatitis B is common. Teenagers not vaccinated as children and all adults at risk of exposure also should be vaccinated against hepatitis B. Three doses are recommended.Key termsAntibody — A substance formed in the body in response to a foreign body, such as a virus, which can then attack and destroy the invading virus.Antigen — Part of an invading microorganism, such as a virus, that causes tissue damage (in hepatitis, to the liver), and that also stimulates the body's immune system to produce antibodies.Cirrhosis — The end result of many forms of liver disease, the condition of the liver when its cells have been damaged or destroyed and are replaced by scar tissue.Vaccine — A substance prepared from a weakened or killed virus which, when injected, helps the body to form antibodies that will attack an invading virus and may prevent infection altogether.Those at increased risk of getting hepatitis B, and who therefore should be vaccinated, include:- household contacts of a person carrying HBV
- healthcare workers who often come in contact with patients' blood or other body fluids
- patients with kidney disease who periodically undergo hemodialysis
- homosexual men who are sexually active, and heterosexuals who have multiple sex partners
- persons coming from areas where HBV infection is a major problem
- prisoners and others living in crowded institutions
- drug abusers who use needles to inject drugs into their veins
Studies released in 2003 showed increased risk of nonresponse to hepatitis B vaccines among adults over age 30. This may be related to age-associated changes in the immune system.ResourcesPeriodicals"Antiviral Effective Against Hepatitis B Virus in HIV-coinfected." Virus Weekly January 28, 2003: 16.Bauer, Jeff. "Co-infection with Hepatitis B and HIV Increases Men's Risks of Death from Liver Disease." RN March 2003: 97.Elliott, William T. "Warfarin Effectively Prevents Venous Thromboembolism (Pharmacology Watch)." Critical Care Alert April 2003."Hepatitis B Vaccine Loses Effectiveness in Older Adults." Vaccine Weekly January 29, 2003: 23.OrganizationsHepatitis B Foundation. 101 Greenwood Ave., Suite 570, Jenkintown, PA 19046. (215) 884-8786. 〈info@hepb.org〉.vi·ral hep·a·ti·tis type Ba viral disease with a long incubation period (usually 50-160 days), caused by a hepatitis 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 or by sexual transmission; clinically and pathologically similar to viral hepatitis type A, but there is no cross-protective immunity; HBsAg is found in the serum and the hepatitis delta virus occurs in some patients. May lead to acute or chronic liver disease. Synonym(s): hepatitis B, serum hepatitis, transfusion hepatitis, virus B hepatitishepatitis Bn. A viral hepatitis that is either acute or chronic, caused by a DNA virus, and usually transmitted by infected blood products (as through transfusion), contaminated needles, or exposure to infected bodily fluids through sexual intercourse. It can cause chronic liver damage and cancer. Also called serum hepatitis.hepatitis B (1) Hepatitis B virus.
(2) The disease caused by hepatitis B virus.hepatitis B Hepatology Liver inflammation by HBV, a small, highly contagious DNA virus of the Hepadnaviridae family Epidemiology 60-110 day incubation, via exchange of body fluids–eg, blood, semen, etc Clinical Sx from malaise to death; acute HBV infection is similar to HAV, with headache, anorexia, nausea, ± vomiting, low fever, jaundice, itching, RUQ tenderness Lab ↑ transaminases, ↑ BR, mild hemolysis, normal/↓ hematocrit & Hb concentrations, mild hemolysis, ↓ PMNs, relative lymphocytosis–total WBC ± 12,000/mm Stages of HBV infection Acute, convalescent, chronic, determined by various viral antigens & antibodies; early hepatitis B is characterized by sublobular involvement of all cells, later stages by scattered antigen-positive hepatocytes Serology See Hepatitis panel. vi·ral hep·a·ti·tis type B (vī'răl hep'ă-tī'tis tīp) A virus disease with a long incubation period (usually 50-160 days), caused by hepatitis B virus (family Hepadnaviridae, genus Orthohepadnavirus); transmitted by blood or blood products, contaminated needles or instruments, or sexual contact; differs from hepatitis A in having a higher mortality rate and in the possibility of progression to a chronic disease, a carrier state, or both. Superinfection with hepatitis D can greatly exacerbate the effect of hepatitis B.
Synonym(s): hepatitis B. hepatitis B Liver inflammation caused by the hepatitis B virus (HBV), which is transmitted in blood or blood products or in other body fluids and can be spread from mother to baby during, or soon after, birth. The commonest mode of spread is by shared intravenous needles. Male homosexuals are greatly at risk. The disease is similar to hepatitis A, but more severe. There is a significant death rate in the acute stage and 10 per cent of those who recover become carriers and may develop complications, including CIRRHOSIS and cancer of the liver. Vaccination against HBV is effective and treatments have recently been developed using interferon alpha and the antiviral drugs lamivudine, adefovir dipivoxil or entecavir.Patient discussion about hepatitis BQ. hepatitis b A. if info about hepatitis B is what you are looking for, here is a great animation that can clarify what's it all about:
http://www.nlm.nih.gov/medlineplus/tutorials/hepatitisb/htm/lesson.htm Q. can the hepatitis b vaccination cause a soar throat? A. yes it can be very probable!
before you would like to go on with any vaccination, you should check out this very long list of links:
http://www.aegis.ch/neu/links.html
at the bottom you will also find links in english. vaccinations in general are very disputable/dubious and it is probably time that we learn about it. Q. Should I vaccinate my newborn against Hepatitis B? I am 9 months pregnant and am expecting to give birth anytime soon. I understood that my newborn will receive a vaccine against Hepatitis B in the hospital. Why is this so?A. because this is bullshit! Hey! Wake up! the lymph system of your baby will only be "ready and finished" after three years! so how should your baby manage a toxic vaccination? do you know what they put in the vaccination? they put hepatitis B pathogens/virus with the hope that your baby will be able to build an anti-hepatitis B pathogen and so manage itself in the future hepatitis B! how should your baby do that, when his lymph-system just started to develop itself and will only be ready in three years? please read in the links i send to you:
before you would like to go on with any vaccination, you should check out this very long list of links:
http://www.aegis.ch/neu/links.html
at the bottom you will also find links in english. vaccinations in general are very disputable/dubious and it is probably time that we learn about it. More discussions about hepatitis BSee HepB
See HBhepatitis B
Related to hepatitis B: hepatitis D, hepatitis B vaccineSynonyms for hepatitis Bnoun an acute (sometimes fatal) form of viral hepatitis caused by a DNA virus that tends to persist in the blood serum and is transmitted by sexual contact or by transfusion or by ingestion of contaminated blood or other bodily fluidsSynonymsRelated Words |