Hepatitis B Infection- HBsAg

The Slide covers for the- Hepatitis B Virus and Infection. INTRODUCTION, MODES OF TRANSMISSION, HIGH RISK GROUPS, PATHOGENESIS, CLINICAL MANIFESTATION, DIAGNOSIS, PROPHYLAXIS, PREVENTION.

1. Bishwash Poudel -Medical Laboratory Technologist ( BSc.MLT -RGUHS, Bangalore)

2. Contents INTRODUCTION MODES OF TRANSMISSION HIGH RISK GROUPS PATHOGENESIS CLINICAL MANIFESTATION DIAGNOSIS PROPHYLAXIS PREVENTION

3. Introduction Inflammation of liver What causes liver inflammation? Viruses- Hepatitis A, B, C, D, E Viruses other than hepatitis- CMV, HSV, EBV, YFV Bacteria, fungi, parasites Alcohol, drugs

4. Types

5. A liver infection caused by the hepatitis B virus (HBV) Discovered by Dr. Baruch Blumberg in 1995 in Australian aborigines Also known as Australian antigens Previous name: serum hepatitis (before the discovery of the virus) 100 times more infectious than HIV

6. Structure

7. Mod es of transmission Parenteral route As little as 0.00001ml can be infectious Sexual transmission Vertical transmission Other includes Exposed of virus in open lesion

8. High risk groups Surgeons (maximum risk) Paramedical workers Sex workers especially homosexual males Recipients of blood transfusion and organ transplantation Drug addicts

9. Pathogenesis

10. Stages of Liver Damage

11. Clinical Manifes-tation Incubation period: 90 days (range: 60-150 days) Onset is slow and insidious Can cause both acute and chronic hepatitis

12. Antigen markers: HBsAg, HBeAg , HBcAg Antibody markers: HBsAb , HBeAb , HBcAb Molecular markers: HBV DNA Non-specific markers: elevated liver enzymes and serum bilirubin

13. Antigen markers HBsAg 1 st marker to appear Appears before elevation of transaminases and clinical evidence of hepatitis Disappears in 2 months, but may last for 6 months or years in some cases

14. Antigen markers HBeAg Appears along with HBsAg Indicates active viral replication and high viral infectivity HBcAg Hidden antigen Not demonstrable in circulation Can be detected in hepatocytes by IF test.

15. Antibody marker Anti- HBcIgM 1 st Ab to appear; within first 1-2 weeks after appearance of HBsAg Lasts for 3-6 months Indicates acute hepatitis B infection Only marker present during the period between appearance of anti- HBsAb and disappearance of HBsAg

16. Antibody marker Anti- HBcIgG Appears in late acute stage Remains positive in chronic and carrier stage Indicates past or chronic infection

17. Antibody marker Anti-HBs ( HBsAb ) Appears after HBsAg disappears and remains elevated indefinitely Indicates recovery, immunity and non-infectivity (i.e. Stoppage of transmission) Only marker of Hepatitis B vaccination

18. Antibody marker Molecular marker Anti- HBeAg Appear after clearance of HBeAg Remain elevated for variable period Signifies diminished viral replication and decreased infectivity HBV DNA Represent viral replication and infectivity

19. Interpretation

20. Detection Methods Antigen detection Rapid test- Immunochromatographic test (ICT) ELISA CLIA RIA Molecular method PCR

21. Anti-viral drugs vaccination

22. Active immunization (Hep B vaccine) Route of administration: IM over deltoid region (infants- anterolateral thigh) Dosage: 10-20µg/dose (<10years- half dose is given) Schedule Adults- 3 doses given at 0, 1 and 6 months Under national immunization schedule- given at 6, 10 and 14 weeks (along with DPT)

23. Passive immunization(HBIG) Indications: used where immediate protection is warranted Exposed to HBsAg positive blood Sexual contact with acute Hep B patient Neonates born to Hep B carrier mothers Post liver transplant patient who need protection against HBV infection Should be started immediately( ideally within 6hrs, not later than 48hrs) Recommended dose: 0.05-0.07 ml/kg body weight; 2 doses given at 30 days apart .

24. Combined immunization Combined immunization with HBIG and vaccine - more efficacious than HBIG alone. Recommended for neonates born to HBV infected mothers Dosage: single dose of 0.5ml of HBIG after birth, followed by full course of vaccine( 1 st dose-given within 12hrs of birth).

25. Post-exposure prophylaxis If exposed person is vaccinated and Ab titer is protective(>10IU/ml)- no further T/t is needed. If exposed person is vaccinated and Ab titer is not protective(<10IU/ml) HBIG- start immediately Vaccine- single dose should be given within 7 days of exposure If exposed person is not vaccinated: HBIG and full course of vaccine (3doses) are needed.

26. In context of our organization Sample collection: clot activator tube (yellow tube) Insufficient and hemolyzed sample will not be accepted. HIV, HBsAg and HCV is done in BIO-RAD (EVOLIS) by ELISA method. Positive results: Repeat test for confirmation Inform to lab supervisor Inform to responsible person Call the applicant Escort him/her to NPHL Responsible person will collect the report from NPHL

27. Procedure Collect sample from nursing station Centrifuge Turn on the power supply(Bio-Rad EVOLIS) Run the daily maintenance Prepare the required reagents and strips of the HBsAg Program the HBsAg test Run the test After result comes export the results to Glosys