Lecture 6-hepatitis
- 2. Introduction • Viral hepatitis is the most common liver disease worldwide. • The viral agents of acute hepatitis can be divided in to two major groups – hepatitis viruses: A, B, C, D & E – hepatitis viruses: Epstein- Barr virus, cytomegalovirus, herpes virus, etc. • Primary hepatitis viruses attack primarily the liver and have little direct effect on other organ system. • Secondary viruses involve the liver secondary in the curse of systemic infection of another body system.
- 3. Hepatitis A virus(Infectious or short- incubation hepatitis) • Hepatitis A virus is a small, single stranded RNA virus when seen by electron microscope. Infection can be acquired by ingestion of virus in contaminated food or water from hands or other objects contaminated with infected feces (fecooral routes), after exposure within 2-6 weeks clinical symptoms will develop.
- 4. Laboratory diagnosis • Testing methods for hepatitis A virus include the following: – Total antibody by enzyme immunoassay (EIA) – IgM antibody by RIA – HA antigen by radioimmunoassayt (RIA)
- 6. Hepatitis B virus (Long term or serum hepatitis) • Hepatitis B virus is a double stranded, DNA virus. It is the classic example of a virus acquired through blood transfusion. • It has various antigens hepatitis B surface antigen, an outer coat, hepatitis B antigen that is an inner core component and hepatitis B core antigen.
- 7. transmission of hepatitis B • The major routes of transmission of hepatitis B virus included blood transfusion, sexual inter course, transplacental and sharing of contaminated needle. • The incubation period of hepatitis B virus may range from 6-26 weeks. • Infected patients manifest hepatitis B virus in all body fluids including blood, feces, urine, saliva, semen, tear and milk.
- 8. Laboratory diagnosis • Serum that is collected in acute stage of illness can be tested by: – Counterimmunoelectrophoresis – Enzyme Linked immuno sorbent assay – Reverse passive Hemagglutination test • Reverse passive hemagglutination is the commonly employed test since it is less expensive and sensitive test.
- 10. Hepatitis C virus • Viral hepatitis caused by hepatitis c virus, the identification of this virus is not clear, sometime it known as non-A/non-B hepatitis. This virus is commonly acquired by contaminated blood and blood products.
- 11. Laboratory diagnosis • Hepatitis C virus antibody can be detected from serum usually by radioimmunoassay.
- 12. Hepatitis D virus (Delta virus) • It is defective or incomplete RNA virus that is unable by itself to cause infection, i.e., transmitted through blood products. • HBV is required as a helper to initiate delta infection only persons with acute or chronic HBV infection can be infected with delta agent.
- 13. Laboratory diagnosis- Radio immuno assay
- 14. Hepatitis E virus • This is responsible for large water borne out breaks incubation period 6 weeks. • Laboratory diagnosis: Specific test for IgM & IgG antihepatitis E virus.
- 16. •Any question