A brief introduction of the hepatitis B virus from point of view of microbiology.

2. Introduction to HBV
• Family- Hepadnaviridae
• Genus- Orthohepadnavirus
• Common name- Hepadnavirus
• Virus- Hepatitis B virus: Hepadnavirus type1

3. Discovery
• Serendipitous discovery
• In 1965, by ‘Blumberg’ – surface antigen of
HBV - Australia antigen.
• In 1968, Australia antigen was renamed as
Hepatitis B surface antigen (HBsAg)
• Originally called as ‘Serum Hepatitis’

4. Characteristics
• Partially double stranded DNA genome
• Icosahedral capsid with envelope
• Virion- Dane particle.
• Incubation period: 2-5 months
• Onset: insidious
• Site of latency- Liver

5. Micrograph of Hepatitis B virions

6. Antigenic Structure
• HBsAg- on surface of Dane particle
• HBcAg- nucleoprotein core of Dane particle
• HBeAg- part of core protein- infectivity.
Antigenic Subtypes
• HBsAg- adw, adr, ayw & ayr

7. Transmission
• Humans- reservoir & vector.
• Spread by- direct contact including:
1. Exchange of body secretions.
2. Recipient of contaminated blood products.
3. Percutaneous injection of virus.
4. Perinatal exposure.

8. HBV disease – ‘Endemic’
• Acute infection- 90% resolution
• Fulminant hepatitis
• Chronic hepatits- 9%
• Asymptomatic carrier state
• Chronic persistant
• Chronic active disease

9. THANK YOU!
Presented by:
Rushali Riah
Roll no. 85
III semester