hepatitis b virus

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Done by: Ahmad Mhd Al-dhlawiy Hamad Emad Dhuhayr

+Contents …

General concepts for hepatitis. Types of hepatitis. HBV Structure & Antigens. Transmission \Epidemiology. Pathogenesis & Immunity. Clinical pictures. Laboratory Diagnosis. Treatment \Prevention. References.

+ General Concepts …

VIRAL HEPATITIS :- is a serious disease caused by virus that attacks the liver . There are various strains of viral hepatitis which can cause lifelong infection, cirrhosis ( scarring) of the liver ,

liver cancer , liver failure, and death.

six medically important viruses are commonly described as “hepatitis viruses”:

HAV,HBV,HCV,HDV,HEV,HGV

+Terms for Hepatitis ….

Acute: Short term and/or severe.

Chronic: Lingering or lasting - may or may not be severe

Fulminant: Developing quickly and lasting a short time, high mortality rate.

Cirrhosis: Hardening: may be the result of infection or toxins (e.g. alcohol)

Jaundice: Yellowing of the skin, eyes, etc due to raised levels of bilirubin in the blood due to liver damage.

Hepatocellular carcinoma: is closely associated with hepatitis B, and at least in some regions of the world with hepatitis C virus.

+Viral hepatitis …

+Viral hepatitis …

+ HBV Structure & Antigens

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HBsAg = surface (coat) protein ( 4 phenotypes : adw, adr, ayw and ayr)

HBcAg = inner core protein (a single serotype)

HBeAg = secreted protein; function unknown

+Replication…

+Modes of Transmission for HBV Parenteral - IV drug abusers, health workers are

at increased risk.

Sexual - sex workers and homosexuals are particular at risk.

Perinatal - (Vertical) - mother(HBeAg+) →infant.

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+Incidence of Hepatitis in KSA

+High-risk groups for HBV infection

People from endemic regions Babies of mothers with chronic HBVIntravenous drug abusersPeople with multiple sex partnersHemophiliacs and other patients requiting blood

and blood product treatmentsHealth care personnel who have contact with

blood

+Concentration of Hepatitis B Virus in Various Body Fluids …

High ModerateLow/Not

Detectable

blood semen urineserum vaginal fluid feces

wound exudates saliva sweat

tearsbreastmilk

+Pathogenesis & Immunity … Virus enters hepatocytes via blood

Immune response (cytotoxic T cell) to viral antigens expressed on hepatocyte cell surface responsible for clinical syndrome

5 % become chronic carriers (HBsAg> 6 months)

Higher rate of hepatocellular ca in chronic carriers, especially those who are “e” antigen positive

Hepatitis B surface antibody likely confers lifelong immunity (IgG anti-HBs)

Hepatitis B e Ab indicates low transmissibility

+Clinical pictures …

+Possible Outcomes of HBV Infection

Acute hepatitis B infection

Chronic HBV infection

3-5% of adult-acquired infections

95% of infant-acquired infections

Cirrhosis

Chronic hepatitis

12-25% in 5 years

Liver failure Hepatocellular carcinoma

Liver transplant

6-15% in 5 years 20-23% in 5 years

DeathDeath

+Acute Hepatitis B Infection

+Laboratory Diagnosis …

+Treatment …

Interferon alfa (Intron A) （ Response rate is 30 to 40%.

Lamivudine (Epivir HBV)

(relapse ,drug resistance)

Adefovir dipivoxil (Hepsera)

+ Prevention …

Vaccination - highly effective recombinant vaccines.Hepatitis B Immunoglobulin (HBIG) -exposed within 48 hours of the incident/

neonates whose mothers are HBsAg and HBeAg positive.

Other measures -screening of blood donors, blood and body fluid

precautions.

+Hepatitis B Vaccine

Infants: several options that depend on status of the mother If mother HBsAg negative: birth, 0-2m,4-6m If mother HBsAg positive: vaccine and Hep B immune

globulin within 12 hours of birth, 1-2m, <6m

Adults * 0,1, 6 months

Routine booster doses are NOT routinely recommended for any group

Vaccine recommended in All those aged 0-18 Those at high risk

+References

website

http://www.hepatitis-central.com/hbv/hepbfaq/viroligy.html

http://en.wikipedia.org/wiki/Hepatitis_B

http://www.who.int/mediacentre/factsheets/fs204/en/index.html

http://www.cdc.gov/vaccines/pubs/vis/downloads/vis-hep-b.pdf

http://www.worldhepatitisalliance.org/AboutViralHepatitis/Prevention_Diagnosis_Treatment.aspx

http://emedicine.medscape.com/article/177632-overview

Text books

Richard A, HARVEY, Pamela C,Champe, Bruce D, Fisher. Microbiology 2nd edition. Lippicott Williams & wilkins. Chapter 26. PP(273-282)

Raphael Rubin, David S. Strayer. Rubin’s pathology 5th edition. Lippicott Williams & wilkins. Chapter 14. PP(637-640)

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AHMED AL DAHLAWY

HAMAD EMAD THUHAYR