Hepatitis B VirusHepatitis B Virus

Hepatitis B - Clinical

FeaturesHepatitis B - Clinical

Features• Incubation period: Average 60-90 days

Range 45-180 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%

Acute Hepatitis B Virus Infection with Recovery

Acute Hepatitis B Virus Infection with RecoveryTypical Serologic CourseTypical Serologic Course

Weeks after ExposureWeeks after Exposure

TiterTiter

Symptoms

HBeAg anti-HBe

Total anti-HBc

IgM anti-HBc anti-HBsHBsAg

0 4 8 12 16 20 24 28 32 36 52 100

Progression to Chronic Hepatitis B Virus Infection

Progression to Chronic Hepatitis B Virus InfectionTypical Serologic CourseTypical Serologic Course

Weeks after ExposureWeeks after Exposure

TiterTiter

IgM anti-HBc

Total anti-HBc

HBsAg

Acute(6 months)

HBeAg

Chronic(Years)

anti-HBe

0 4 8 12 16 20 24 28 32 36 52 Years

Rate of Reported Hepatitis B by Age Group

United States, 1990

Rate of Reported Hepatitis B by Age Group

United States, 1990

Age Group (Years)Age Group (Years)

Ra

te (

pe

r 1

00,0

00

)R

ate

(p

er

100

,00

0)

Source: CDC Viral Hepatitis Surveillance Program

0-14 15-19 20-29 30-39 40+0

5

10

15

20

25

Age at Aquisition of Acute and Chronic HBV Infection

United States, 1989 Estimates

Age at Aquisition of Acute and Chronic HBV Infection

United States, 1989 Estimates

Acute HBV Infections Chronic HBV Infections

(4% ) Perinatal (24%)(4%) Children (12%)

(1-10 yrs)(8%) Adolescent (6%)

Adult(83%)

Adult(59%)

Outcome of Hepatitis B Virus Infectionby Age at Infection

Outcome of Hepatitis B Virus Infectionby Age at Infection

Symptomatic Infection

Chronic Infection

Age at Infection

Ch

ron

ic In

fect

ion

(%

)

Sym

pto

mat

ic In

fect

ion

(%

)

Birth 1-6 months 7-12 months 1-4 years Older Childrenand Adults

0

20

40

60

80

100100

80

60

40

20

0

• 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

Global Patterns of Chronic HBV Infection

Global Patterns of Chronic HBV Infection

Geographic Distribution of Chronic HBV Infection

Geographic Distribution of Chronic HBV Infection

HBsAg Prevalence

8% - High

2-7% - Intermediate

<2% - Low

Concentration of Hepatitis B Virus

in Various Body Fluids

Concentration of Hepatitis B Virus

in Various Body Fluids

High ModerateLow/Not

Detectable

blood semen urineserum vaginal fluid feces

wound exudates saliva sweat

tearsbreastmilk

•Sexual

•Parenteral

•Perinatal

Hepatitis B Virus

Modes of TransmissionHepatitis B Virus

Modes of Transmission

Risk Factors for Acute Hepatitis B

United States, 1992-1993

Risk Factors for Acute Hepatitis B

United States, 1992-1993

* Includes sexual contact with acute cases, carriers, and multiple partners. Source: CDC Sentinel Counties Study of Viral Hepatitis

Heterosexual* (41%)

Homosexual Activity (9%)Household Contact (2%)

Health Care Employment (1%)

Other (1%)Unknown (31%)

InjectingDrug Use

(15%)

• Prevent chronic HBV Infection• Prevent chronic liver disease• Prevent primary hepatocellular

carcinoma• Prevent acute symptomatic HBV

infection

Elimination of Hepatitis B Virus Transmission United States

Elimination of Hepatitis B Virus Transmission United States

Objectives

• Prevent perinatal HBV transmission• Routine vaccination of all infants• Vaccination of children in high-risk groups• Vaccination of adolescents

– all unvaccinated children at 11-12 years of age

– “high-risk” adolescents at all ages• Vaccination of adults in high-risk groups

Elimination of Hepatitis B Virus Transmission United States

Elimination of Hepatitis B Virus Transmission United States

Strategy

Estimated Incidence of Acute Hepatitis B

United States, 1978-1995

Estimated Incidence of Acute Hepatitis B

United States, 1978-1995Vaccinelicensed

HBsAg screening

of pregnant women

recommended

Infantimmunizati

onrecommend

ed

OSHA Ruleenacted

Adolescent immunizati

on recommend

ed

*Decline among

homosexual men & HCWs

Decline among

injectingdrug users

80

70

60

50

40

30

20

10

0

78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95

Year

Ca

ses

per

10

0,0

00 P

op

ula

tio

n

* Provisional date