3. Viral Hepatitis
Types of Hepatitis
A B C D E G
Source of Feces Blood, body Blood, body Blood, body Feces Blood
fluids fluids
virus fluids
Route of Fecal-Oral Childbirth, Needles, Needles, sex, Fecal-Oral Transfusion
Transmission transfusion transfusion (requires
needles, sex,
(sex, childbirth) (requires HBV, HCV,
transfusion HBV co- or HIV co-
infection) infection)
Chronic No Yes Yes Yes No No
Infection (whether it’s
pathogenic to
humans
remains
unclear)
Prevention Vaccine Vaccine Blood donor HBV Vaccine Ensure safe Blood donor
Immuno- screening, risk drinking screening
globulin
Immuno- management, water
globulin education
CDC fact sheets, available at www.cdc.gov
4.
5.
6. Hepatitis A Virus
• RNA virus
• Incubation period: 4 weeks
• Replication limited to the liver
• Virus present in liver, bile, stools, and blood
• Infectivity diminishes once jaundice appears
• Inactivation by boiling; formaldehyde, chlorine
• Prevention by vaccination
• Serologic marker: Anti HAV IgM
7.
8. Hepatitis B
• DNA virus
• Hepadnaviruses (hepatotropic)
• Incubation period: 60 days
• HBsAg+ precedes ALT elevation, symptoms
• Extrahepatic sites: lymph nodes, bone marrow,
lymphocytes, spleen, pancreas
9. Hepatitis B
• Transmission of HBV varies by geographic area:
Mother to infant, child-to-child
China, Southeast Asia, Middle
East and parts of Africa and South
America
Parenteral Route (Intravenous or
Intramuscular)
Intimate contact
North America, Australia,
Western Europe, temperate
South America
10. High-risk Individuals
Infants born to HBV+ Sexual partners of HBV
mothers carriers
Adoptive families of People with sexually
children born in endemic transmitted diseases
areas
Intravenous drug users
Recipients of blood
products, including People with multiple
transfusions sexual partners
Hemodialysis patients
Healthcare workers
11. Acute vs Chronic
Hepatitis B
Acute Chronic
disease in which HBsAg Persistence of HBsAg for
Definition persists for less than 6 more than 6 months
months
Incubation Immune Tolerance
Phases Prodromal Clearance
Icteric Non-replicative
1. Usually subclinical in children 1. Can be HBeAg (+) or (-)
Characteristics 2. 30%-50% of adult patients 2. Viral load is associated with
develop clinical manifestations disease activity
3. May become fulminant 3. May progress to fibrosis,
cirrhosis, or HCC
12. Signs and Symptoms
Acute Chronic
May be asymptomatic Usually asymptomatic
Flu-like symptoms Malaise/Fatigue
Skin Rash Extra-hepatic symptoms
Jaundice Signs/symptoms of liver failure
Light-colored stools Hepatocellular carcinoma
Dark-colored urine
13.
14. Pathogenesis of HBV Infection
Hepatocyte Uninfected Re-infection
regeneration hepatocytes
Infection HBV
production
Immune HBV-infected
response hepatocytes
Alcohol,
co-infection
etc.
Inflammation
and cell death
Clinical hepatitis
Averett DR and Mason WS. Viral Hep. Rev. 1995; 1:129–42
15. Pathogenesis of Chronic HBV Infection
Viral replication
Evidence of disease
Tissue
damage
Immune
Scarring
response
Host and Transplant
environmental factors Cirrhosis or
(e.g. alcohol, co-infection) Death
HCC
Adapted from Dr Z Goodman, Armed Forces Institute of Pathology, Washington, DC
16. Prevention of HBV Infection
• Screening of blood/organ/tissue donors
• Hepatitis B vaccine
– Available since 1981
– Vaccination programmes adopted in >150 countries worldwide
– Inactivated or recombinant HBsAg
– Routine vaccination of infants and previously unvaccinated
children (by age 11)
– Catch-up vaccination of high-risk groups of all ages
– Screening pregnant women and rapid vaccination of infants born
to infected women (HBIg and vaccine)
• Infants born to infected mothers must be vaccinated within the first
12 hours of life
WHO-CSR, HBV Report 2002, available at www.who.int/emc-documents (12/10/2003)
17. Prevention of HBV Infection
• Screening of blood/organ/tissue donors
• Hepatitis B vaccine
– Available since 1981
– Vaccination programmes adopted in >150 countries worldwide
– Inactivated or recombinant HBsAg
– Routine vaccination of infants and previously unvaccinated
children (by age 11)
– Catch-up vaccination of high-risk groups of all ages
– Screening pregnant women and rapid vaccination of infants born
to infected women (HBIg and vaccine)
• Infants born to infected mothers must be vaccinated within the first
12 hours of life
WHO-CSR, HBV Report 2002, available at www.who.int/emc-documents (12/10/2003)
