Hepatitis B and C乙型和丙型肝炎.docx

Hepatitis BDefinition Hepatitis B is inflammation of Liver caused by the hepatitis Bvirus(HBV) HBV is an envelopedviruscontaining a partially double stranded, circular DNAgenome, and classified within the family hepadnavirusClassification Acute Hepatitis (95%) Newly acquired infection Affected individuals notice symptoms approximately 1 to 4 months after exposure to the virus Symptoms resolve over weeks to months and they are cured of the infection Chronic Hepatitis (5%) Hepatitis B virus tests (HBsAg+) are positive after 6 months Infection with HBV that last longer than 6 month. Once infected, never go away. Might progress to develop Liver cirrhosis and hepatocellular carcinoma. FatalThe transition from acute hepatitis B to chronic hepatitis B signifies a failure of the immune response to eradicate the virus.Incubation Period The incubation period is usually 45-180 days with an average of 60-90 days.Transmission routes Blood and blood products Needle stick injurieso Hepatitis B is highly infectiouso Sharing of needles among IV drugs abuser Sexual contactso Almost all the body fluids consists the proteino Seminal fluid may contain of the virus Vertical transmissiono Vertical transmission from maternal to child during delivery through the birth canalRisk Factor High risk sexual behaviour Unprotected sex with more than one partner Unprotected sex with someone whos infected with hbv Sexual contact with same gender Share needles during intravenous (IV) drug use Share a household with someone who has a chronic HBV infection Occupation exposes to human blood Contaminated blood products Contaminated surgical equipment Receive hemodialysis for end-stage kidney (renal) disease Travel to regions with high infection rates of HBV, such as Africa, Central and Southeast Asia, and Eastern EuropePathogenesis HBV enter the new host, infect liver cells, hepatocytes. The binding of these viral antigens to hepatocyte receptors induces viral entry by receptor-mediated endocytosis and uncoats in the cytoplasm Within the cytoplasm, the core particle of the virion translocates its content of viral DNA and DNA polymerase into the hepatocyte nucleus The DNA is then organized to form a viral mini-chromosome. Once within the cell nucleus, the hepatitis B genome is transcribed into mRNA (messenger RNA), where it is subsequently translated into hepatitis B viral surface proteins, viral core proteins, DNA polymerase, and hepatitis B e-antigen protein. The cell then assembles live copies of the virus. The copies of the virus are released from the liver cell membrane into the bloodstream and from there can infect other liver cells and thus replicate effectively.* The virus main target is the liver because the virus possesses surface antigens specific for receptors found on liver cells only.* HBV infection in itself does not lead to the death of infected hepatocytes. HBV in a non-cytolytic infection. Liver damage however, arises from cytolytic effects of the immune systems cytotoxic T lymphocytes (CTL) which attempt to clear infection by killing infected cellsSymptoms- Asymptomatic at early periodAcute Hepatitis BChronic Hepatitis BLoss of AppetiteNausea and vomitingExtreme TirednessTiredness, depression and irritabilityFeverItchy skin (bile salt product deposit on skin)Abdominal PainPain in the liver (upper, right side of abdomen)Muscle and Joint painJoint aches and painsJaundice (After 12 weeks after infection)Dark urineClay-colored stool, diarrheaComplication1. Jaundice2. Liver Cirrhosis3. Liver failure4. Liver carcinomaLiver is responsible to control bilirubin level. Disturbed function of Liver fails to filter excess bilirubin.Sign1. Jaundice (Yellow skin, yellow eye) 2. Pruritus 3. Dark Urine 4. Gianotti-Crosti Syndrome indicator of HBV virus inflammation, present on children skin5. Spider nevi / spider angioma Increased level of estrogen in the body Liver is responsible for breaking down and removing excess estrogen6. Terrys nail Hepatitis B associated with cirrhosis7. Sign of ascites8. Lethargy9. Hepatomegaly10. Blood in the stoolTest 1. Blood tests, which look for markers of the hepatitis B virus in the blood.To understand the tests, it is important to understand two basic medical terms: antigena foreign substance in the body, such as the hepatitis B virus; and antibodya protein that the immune system makes in responses to a foreign substance. Antibodies can be produced in response to a vaccine or a natural infection.TestAbbreviationWhat it showsHepatitis B surface antigenHBsAgShows that the person is infectedwith hepatitis B. It can be detected during acute and chronic infection.Hepatitis B surface antibodyHBsAb or Anti-HBsShows that the person hasdeveloped immunity to hepatitis B. It can be detected in people who have recovered from hepatitis B or been vaccinated against hepatitis B.Hepatitis B e antigenHBeAgShows that hepatitis B virus is multiplying.Hepatitis B e antibodyHBeAb or Anti-HBeShows that the persons immune system has responded against hepatitis B and the virus is not actively replicating.Hepatitis B core antibodyHBcAb or Anti-HBcShows that a person has been infected with hepatitis B but does not provide any protection against infection.Hepatitis B virus DNAHBV DNAMeasures the amount of hepatitis B virus in the bloodstream and indicates how actively the virus is multiplying.2. Liver Function Tests (LFTs) One important test is the Alanine Aminotransferase (ALT). The ALT is released from liver cells into the bloodstream when the liver is injured. An ALT level above normal may indicate liver damage. ALT levels are included in the regular monitoring of all chronic hepatitis B patients; this test can also be useful in deciding whether a patient would benefit from treatment, or for evaluating how well a current treatment is working;3. Liver biopsy The tissue is examined under a microscope to look for inflammation or liver damage 4. Alpha-fetoprotein is a blood test which can sometimes detect liver cancerHepatitis CDefinition Hepatitis C is a liver disease that results from infection with the Hepatitis C virus (HCV). The HCV genome is a single-stranded, positive-sense RNA molecule.Classification Acute Hepatitis C virus infection A clear point of exposure and a positive HCV RNA within six months or a significant rise in serum alanine aminotransferase or seroconversion in which antibody and/or HCV RNA is absent from a first and present in a second sample. Short-term illness that occurs within the first 6 months after someone is exposed to the Hepatitis C virus. For most people, acute infection leads to chronic infection. Chronic Hepatitis C virus infection Ongoing infection with hepatitis C virus beyond the acute phase. Mild disease is present when inflammation of the liver tissue is absent or largely confined to the portal tracts with no evidence of fibrous tissue extending between the portal tracts. Moderate liver disease is described when there is significant inflammation and/or liver cell damage associated with increased fibrous tissue extending beyond the portal tracts but not resulting in nodule formation. Severe disease occurs when patients have developed bridging fibrosis or cirrhosis (histologically proven or otherwise) of the liver, whether there are clinical signs of liver dysfunction or not.Incubation Period The incubation period ranges from 2 weeks to 6 months, most commonly about 6-9 weeks. In chronic Hepatitis C infections, the virus does not resolve or clear after 6 months. Chronic infections may persist for up to 20 years before onset of cirrhosis or cancer of the liver.Mode of TransmissionHepatitis B is found in blood, seminal fluids, vaginal secretions, and other body fluids. The virus can be spread by: Unprotected sexual contact with an infected person, especially among persons with multiple sex partners or men who have sex with men (MSM) Contact with contaminated needles, especially injection drug equipment. Other items such as tattoo and body piercing instruments, razors, and toothbrushes may be contaminated with infected blood An infected mother to her infant during delivery Household contact with an infected person Occupational exposure through accidental needle stickRisk Factor1. IV Drug use2. Accidental needle sticks3. Blood transfusion or organ transplant (especially before 1992)4. Intranasal cocaine use5. HIV and HCV infected mother6. Unprotected sex7. Haemodialysis SymptomsPhysical Sign1. Fatigue and Brain fog2. Edema3. Mood swing, anxiety and depression4. Jaundice5. Spider angioma Extra-hepatic disorders are found outside of the liver. But for people with hepatitis C they can be triggered by the virus. Having chronic HCV does not mean these disorders will develop but they are a risk. Some of these include:6. Dryness of the mucous membrane lining the eyelids and outer eye surface caused by insufficient secretion of tears (keratoconjunctvitis sicca)7. Dryness of the mouth and eyes and a feeling of grittiness in the eyes. This is caused by the progressive destruction of sweat, saliva and tear glands (a form of keratoconjunctvitis called Sjogrens syndrome).8. Flat, itchy patches of skin, usually found on the wrists, shins, lower back, genitalia and sometimes the scalp (lichen planus).9. Inflammation of the tiny blood vessels the kidneys use for filtering waste (glomerulonephritis)10. Sensitivity to light, leading to blisters and ulcerations of the skin in areas such as the face, ears and backs of the hand (porphyria cutanea tarda).11. Arthritis :HCV related RA is an autoimmune disorder that results in antibodies starting to attack normal body tissueTest1. Hepatitis C Antibody test (HCV Ab, anti-HCV) This is the first test for determining whether you have been infected with hepatitis C. If this test result is positive, it means your body was exposed to the hepatitis C virus and made antibodies. However, it does not tell you whether you are still infected with hepatitis C. If the antibody test result is positive, you should be tested for hepatitis C RNA (see Hepatitis C RNA), which determines whether you are chronically infected.2. Hepatitis C RNA qualitative testing The qualitative HCV RNA tests use either a process called polymerase chain reaction (PCR) or a process called transcription-mediated amplification (TMA). The result is reported as either detected or not detected. If a qualitative RNA test is positive (detected), then it is confirmed that the patient has chronic hepatitis C. The qualitative test is more accurate than the quantitative test because qualitative tests are able to detect very low levels of the virus. 3. Hepatitis C RIBA The hepatitis C recombinant immunoblot assay (RIBA) is the confirmation test