1. Hepatitis B Virus 28

2. Hepatitis B - Clinical Features
Incubation period: Average days
Range days
Clinical illness (jaundice): <5 yrs, <10% 5 yrs, 30%-50%
Acute case-fatality rate: 0.5%-1%
Chronic infection: <5 yrs, 30%-90% 5 yrs, 2%-10%
Premature mortality from chronic liver disease: 15%-25% 29

3. Typical Serologic Course
Acute Hepatitis B Virus Infection with Recovery
Typical Serologic Course
Symptoms
HBeAg
anti-HBe
Total anti-HBc
Titer
anti-HBs
HBsAg
IgM anti-HBc 4 8 12 16 20 24 28 32 36 52
100
Weeks after Exposure 30

4. Typical Serologic Course
Progression to Chronic Hepatitis B Virus Infection
Typical Serologic Course
Acute
(6 months)
Chronic
(Years)
HBeAg
anti-HBe
HBsAg
Total anti-HBc
Titer
IgM anti-HBc 4 8 12 16 20 24 28 32 36 52
Years
Weeks after Exposure 31

5. Rate of Reported Hepatitis B by Age Group
United States, 1990 25 20 15
Rate (per 100,000) 10 5
0-14
15-19
20-29
30-39
40+
Age Group (Years)
Source: CDC Viral Hepatitis Surveillance Program 32

6. Age at Aquisition of Acute and Chronic HBV Infection
United States, 1989 Estimates
(4% ) Perinatal (24%)
(4%) Children (12%)
(1-10 yrs)
(8%) Adolescent (6%)
Adult
(59%)
Adult
(83%)
Acute HBV Infections
Chronic HBV Infections 33

7. Outcome of Hepatitis B Virus Infection
by Age at Infection
100
100 80 80 60 60
Chronic Infection (%)
Chronic Infection
Symptomatic Infection (%) 40 40 20 20
Symptomatic Infection
Birth
1-6 months
7-12 months
1-4 years
Older Children
and Adults
Age at Infection 34

8. Global Patterns of Chronic HBV Infection
High (8%): 45% of global population
lifetime risk of infection >60%
early childhood infections common
Intermediate (2%-7%): 43% of global population
lifetime risk of infection 20%-60%
infections occur in all age groups
Low (<2%): 12% of global population
lifetime risk of infection <20%
most infections occur in adult risk groups 35

9. Geographic Distribution of Chronic HBV Infection
HBsAg Prevalence
8% - High
2-7% - Intermediate
<2% - Low 36

10. Concentration of Hepatitis B Virus
in Various Body Fluids
Low/Not
High
Moderate
Detectable
blood
semen
urine
serum
vaginal fluid
feces
wound exudates
saliva
sweat
tears
breastmilk 1 1 1

11. Hepatitis B Virus Modes of Transmission Sexual Parenteral Perinatal 2

12. Risk Factors for Acute Hepatitis B
United States,
Heterosexual*
(41%)
Injecting
Drug Use
(15%)
Homosexual Activity (9%)
Household Contact (2%)
Health Care Employment (1%)
Unknown (31%)
Other (1%)
* Includes sexual contact with acute cases, carriers, and multiple partners.
Source: CDC Sentinel Counties Study of Viral Hepatitis 3 3 3

13. Elimination of Hepatitis B Virus Transmission United States
Objectives
Prevent chronic HBV Infection
Prevent chronic liver disease
Prevent primary hepatocellular carcinoma
Prevent acute symptomatic HBV infection 4 4 4

14. Elimination of Hepatitis B Virus Transmission United States
Strategy
Prevent perinatal HBV transmission
Routine vaccination of all infants
Vaccination of children in high-risk groups
Vaccination of adolescents
all unvaccinated children at years of age
“high-risk” adolescents at all ages
Vaccination of adults in high-risk groups 5 5 5

15. * Estimated Incidence of Acute Hepatitis B United States, 1978-1995
HBsAg screening
of pregnant women recommended 80
Infant
immunization
recommended
Vaccine
licensed 70 60
OSHA Rule
enacted 50
Cases per 100,000 Population
Adolescent immunization recommended 40 30 20 *
Decline among homosexual men & HCWs
Decline among injecting
drug users 10 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95
Year
* Provisional date 6 6 6