viral hepatitis- types, symptoms, risk factors

overview of viral hepatitis infection and their types. overview of each type is given.

1. HEPATITIS DONE BY RAJA RAJESWARI.S I MSC MICROBIOLOGY

2. TOPICS Etymology Introduction Origin Types of viral hepatitis Type A hepatitis Type B hepatitis Type C hepatitis Type D hepatitis Type E hepatitis References

3. ETYMOLOGY The word ‘hepatitis’ is derived from the Latin word ‘   hēpatītis ’ and from the ancient Greek word ‘ hepar ’ meaning liver. In modern Greek ‘ ites ’ means inflammation of . Thus the word hepatitis means ‘inflammation of the liver .’

4. INTRODUCTION Hepatitis can be caused due to a number of causes, such as infections, alcohol abuse, trauma or drug induced toxicity. However , in global terms, viral infections are the most important cause of hepatitis . These include infections with herpes simplex virus, cytomegalovirus and Epstein–Barr virus, but the majority of viral liver diseases are by hepatitis viruses. Hepatitis may occur incidentally during many other viral infections, such as yellow fever, Lassa fever, Marburg, cytomegalovirus as mentioned above which is not included in the category of viral hepatitis. Hepatitis viruses are taxonomically unrelated.

5. VIRAL HEPATITIS

6. Greek mythology- Titan Prometheus stole fire from Zeus and gave to mankind. Titan was send to Mount Caucasus. Heracles – saved Titan Prometheus. Hippocrates - 400 BC – jaundice. 5 th century- epidemic of jaundice. 17 th and 18 th century- Europe. ‘Campaign jaundice’ – armies epidemic. 19 th century- Acute Catarrhal Jaundice. 1923 - Blumer

7. HEPATITIS TYPE A VIRUS INTRODUCTION : Hepatitis A formerly known as infectious hepatitis or epidemic jaundice is an acute infectious disease caused by Hepatitis A Virus (HAV). DISCOVERY : 1973, Feinstone and co- workers, Immunoelectron microscopy (IEM). MORPHOLOGY : small, 27 nm, non- enveloped RNA virus, Picorna virus family. RESISTANCE : inactivation of heat at 60º C for one hour, ether and acid at pH 3. SENSITIVE : inactivated at 37º C for 72 hours, and chlorine 1ppm for 30 minutes. MODE OF TRANSMISSION : fecal oral route, parenteral route, sexual transmission. INCUBATION PERIOD : 15- 45 days.

8. DIAGNOSIS : Demonstration of Virus in feces, blood, bile b y IEM. Detection of Antibody b y ELISA. Biochemical tests includes Alanine aminotransferase (ALT ), Bilirubin, Protein. Molecular Diagnosis is by RT PCR of feces. PROPHYLAXIS : Formalin inactivated, alum conjugated vaccine containing HAV grown in human diploid cell culture (2 doses intramuscular injections). TREATMENT : This is symptomatic. No specific antiviral drug is available.

9. HEPATITIS TYPE B VIRUS INTRODUCTION : H epatitis B formerly known as serum hepatitis is an acute systemic infection with major pathology in the liver, caused by Hepatitis B Virus (HBV). DISCOVERY : 1965, Dr. Baruch Blumberg, Australian antigen MORPHOLOGY : 42 nm, enveloped DNA virus, Hepadnavirus family. RESISTANCE : heat stable virus. SENSITIVE : inactivated by 2% glutaraldehyde MODE OF TRANSMISSION : parenteral route, sexual transmission, perinatal (vertical) transmission. INCUBATION PERIOD : 1- 6 months.

10. SYMPTOMS OF HEPATITIS B

11. DIAGNOSIS : Series of blood test is done for screening of HBV viz., Hepatitis B surface antigen test, Hepatitis B core antigen test, Hepatitis B surface antibody test and, L iver function test. PROPHYLAXIS : Hyperimmune Hepatitis B immunoglobulin (HBIG) TREATMENT : No specific treatment is available. Interferon α alone or with combination of lamivudine and famcyclovir .

12. HEPATITIS TYPE C VIRUS INTRODUCTION : Hepatitis C is an infectious disease affecting primarily the liver, caused by the hepatitis C virus (HCV). DISCOVERY : 1989, ‘non- A non- B’ viruses. MORPHOLOGY : 50-60 nm, enveloped ss RNA virus, Flaviviridae family. MODE OF TRANSMISSION : intravenous, sexual transmission, vertical transmission, hemodialysis , healthcare exposure. INCUBATION PERIOD : 15-160 days

13. DIAGNOSIS : A ntibody detection by ELISA, the antigens used are various structural and non- structural proteins cloned in Escherichia coli. Confirmation is done by immunoblot assay. PROPHYLAXIS : Blood screening. No specific active or passive immunisation is available. TREATMENT : Prolonged treatment with interferon α alone or with ribavirin.

14. HEPATITIS TYPE D VIRUS INTRODUCTION : Hepatitis D is an acute or chronic infection caused by Hepatitis D (Delta)Virus (HDV). DISCOVERY : 1977, Rizzetto and co- workers, new viral antigen in the liver cells of infected HBV patients. MORPHOLOGY : spherical, 35- 37 nm, defective enveloped ss RNA virus, deltavirus . MODE OF TRANSMISSION : vertical transmission, homosexual men, blood transfusion, intravenous drugs. CLINICAL FEATURES: 2 types of infection- coinfection and superinfection . INCUBATION PERIOD : 30- 180 days.

15. SYMPTOMS OF HEPATITIS D

16. DIAGNOSIS : I mmunofluorescence to detect delta antigen and to detect anti- delta antibodies by ELISA. PROPHYLAXIS : N o specific prophylaxis exists, but immunisation with HBV vaccine is effective. TREATMENT : N o treatment is available for both acute and chronic type.

17. HEPATITIS TYPE E VIRUS INTRODUCTION : Hepatitis E, also known as Enterically transmitted NANB or Epidemic NANB hepatitis is an acute viral hepatitis which is a self- limiting infection caused by H epatitis E Virus (HEV ). MORPHOLOGY : spherical, 32- 34 nm, non- enveloped ss RNA virus, Caliciviridae family. MODE OF TRANSMISSION : fecal oral route, vertical transmission, blood transfusions. INCUBATION PERIOD : 15-60 days. DIAGNOSIS : ELISA for IgG and IgM antibodies detection and, IEM. PROPHYLAXIS : no specific prophylaxis available.

18. SYMPTOMS OF HEPATITIS E

19. RISK FACTOR

20. REFERENCES Ananthanarayanan R and CK Jayaram Panicker , 1994, ‘Textbook of Microbiology’ Orient Longman. https://bioetymology.blogspot.com/2011/06/hepatitis.html Hepatitis-150918092901-Ival-app6891.pdf www.Medscape.com www.healthline.com ‘California Association for Medical Laboratory Technology’, viral hepatitis 2015: Causes, diagnosis and treatment- course # DL-004