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Viral Hepatitis B (HBV)Viral Hepatitis B (HBV)

Associate Professor Associate Professor Family and Community Medicine DepartmentFamily and Community Medicine Department

King Saud UniversityKing Saud University

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Serum hepatitis, serum jaundice.

Clinical signs & symptoms occur more in adults.

At least 50% of infections are asymptomatic

Onset is usually gradual with anorexia, nausea and

vomiting, often progressing to jaundice.

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• Incubation period: Average 60-90 days Range 45-180 days

• Clinical illness <5 yrs, <10%(jaundice): >5 yrs, 30%-50%

• Acute case-fatality rate: 0.5%-1%

• Chronic infection: <5 yrs, 30%-90% >5 yrs, 2%-10%

• Premature mortality fromchronic liver disease: 15%-25%

Hepatitis B – Clinical Features

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Sym

pto

mati

c I

nfe

cti

on

(%

)

100

Symptomatic Infection

Birt

h

1-6

mos

7-12

mos

1-4

yrs

Old

er

Chi

ldre

nan

d A

dul

ts

80

60

40

20

0

Symptomatic Infection of Hepatitis B Virus by Age at Infection

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0

10

20

30

40

50

60

70

80

90

100

Birth 1-6 mo 7-12 mo 1-4 yrs 5+ yrs

Age of infection

Car

rier

ris

k (%

)

Risk of Chronic HBV Carriage by Age of Risk of Chronic HBV Carriage by Age of InfectionInfection

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Ch

ron

ic I

nfe

ctio

n (

%)

Sym

pto

matic In

fect ion

(%)

100100

Symptomatic Infection

Chronic Infection

Birt

h

1-6

mos

7-12

mos

1-4

yrs

Old

er

Chi

ldre

nan

d A

dul

ts

0

20

40

60

8080

60

40

20

0

Outcome of Hepatitis B Virus Infectionby Age at Infection

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Chronic Hepatitis B Virus InfectionChronic Hepatitis B Virus Infection

•Overall risk: 10% of all acute HBV infections.Overall risk: 10% of all acute HBV infections.

• About 15%-25% of persons with chronic HBV About 15%-25% of persons with chronic HBV

infection might die from either cirrhosis or liver cancerinfection might die from either cirrhosis or liver cancer

• Chronic HBV is theChronic HBV is the primary cause of liver cancer.primary cause of liver cancer.

• Chronic infection occurs in:Chronic infection occurs in:

~ 90% of infants infected with HBV at birth~ 90% of infants infected with HBV at birth

~ 30% of children infected at age 1- 5 years~ 30% of children infected at age 1- 5 years

2- 6% of people infected after age 5 years2- 6% of people infected after age 5 years

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High (>8%): High (>8%): – 45% of global population45% of global population

– early childhood infections commonearly childhood infections common

Intermediate (2%-7%): Intermediate (2%-7%): – 43% of global population43% of global population

– infections occur in all age groupsinfections occur in all age groups

Low (<2%): Low (<2%): – 12% of global population12% of global population

– most infections occur in adult risk groupsmost infections occur in adult risk groups

Global Patterns of Chronic HBV Infection

16/3/200916/3/2009 Dr. Salwa TayelDr. Salwa Tayel 1111

AgentAgent

Susceptible HostSusceptible Host ReservoirReservoir

Mode of transmissionMode of transmission

Cycle of infectionCycle of infection

Portal of ExitPortal of ExitPortal of InletPortal of Inlet

IP

PC

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HBsAg Double-Stranded DNA

HBsAg

HBcAg

HBeAg

Hepatitis B Virus

The presence of HBsAg indicates active infection or chronic The presence of HBsAg indicates active infection or chronic

carrier. carrier.

Antibody to HBsAg, from either disease or vaccine, indicates Antibody to HBsAg, from either disease or vaccine, indicates

immunity.immunity.

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Human (cases and carriers).

Human blood and blood products can transmit Human blood and blood products can transmit

infection if not screened for HBs Ag.infection if not screened for HBs Ag.

Other body fluidsOther body fluids have the virus with varying have the virus with varying

concentrations.concentrations.

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Low/Not

High Moderate Detectable

semenserum vaginal fluidblood

wound exudates saliva

urinefecessweat

tearsbreast milk

Concentration of HBV in Various Body Fluids

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1.Percutaneous: Unsafe injections and

transfusions, organ transplants, sharing

needles, haemodialysis, needle sticks, tattooing

, razors and toothbrushes.

2.Perinatal exposure, especially when HBs Ag

carrier mothers are also HBe Ag positive.

3.Sexual exposure.

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From 45-180 days, average 60-90 days.

• 1-2 months before the onset of symptoms

• during acute clinical course

• during the chronic carrier state which may persist

for life.

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Prevent perinatal HBV transmission Prevent perinatal HBV transmission Routine vaccination of all infantsRoutine vaccination of all infants Vaccination of children in high-risk Vaccination of children in high-risk

groupsgroups Vaccination of adolescents & all Vaccination of adolescents & all

children up through age 18children up through age 18 Vaccination of adults in high-risk Vaccination of adults in high-risk

groupsgroups

Strategy

Elimination of HBV Transmission

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• Licensed in 1982 Licensed in 1982 • Currently, subunit recombinant HBs AgCurrently, subunit recombinant HBs Ag• given given IMIM in the deltoid region. in the deltoid region.

• 3 dose series, typical schedule 0, 1-2, 4-6 months - no 3 dose series, typical schedule 0, 1-2, 4-6 months - no maximum time between doses (no need to repeat missed maximum time between doses (no need to repeat missed doses or restart)doses or restart)

• Protection Protection • ~30-50% dose 1~30-50% dose 1• 75% - dose 275% - dose 2• 96% - dose 396% - dose 3• lower protection in older, immunosuppressive lower protection in older, immunosuppressive

illnesses (e.g., HIV, chronic liver diseases, diabetes), illnesses (e.g., HIV, chronic liver diseases, diabetes), obese, smokersobese, smokers

Hepatitis B Vaccine

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Routine for infantsRoutine for infants

Ages 11-15 Ages 11-15 ““catch upcatch up””, and through age 18 years, and through age 18 years Over 18 Over 18 –– high risk high risk

– Occupational risk health care workers (HCWs)Occupational risk health care workers (HCWs)

– Hemodyalisis patientsHemodyalisis patients

– All clinic clients of All clinic clients of sexually transmitted diseases sexually transmitted diseases ((STD)STD)

– Multiple sex partners or prior STDMultiple sex partners or prior STD

– MSM (Men having sex with men)MSM (Men having sex with men)

– IDU (IDU (injecting drug users)injecting drug users)

– Institution for developmental disability (Staff & Institution for developmental disability (Staff & clients)clients)

Indication of Hepatitis B VaccinationIndication of Hepatitis B Vaccination

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Prevention of perinatal HBV transmission

Prevent perinatal HBV transmission by:Prevent perinatal HBV transmission by:

• screening all pregnant women for screening all pregnant women for hepatitis B surface antigen (HBsAg) & hepatitis B surface antigen (HBsAg) &

• At birth, providing hepatitis B immune At birth, providing hepatitis B immune globulin (HBIG) & globulin (HBIG) & andand

• hepatitis B vaccine to infants of hepatitis B vaccine to infants of HBsAg‑positive mothersHBsAg‑positive mothers

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Immunoglobulins (HBIG):

(HBIG) is indicated in combination with the vaccine in:

needle stick injury

acute sexual exposure

perinatal transmission

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Other preventive measuresIn blood banks:

screening of blood donors

And avoid donors from risky group.

Use of adequately sterilized syringes and Use of adequately sterilized syringes and

needles or preferably use disposal equipment.needles or preferably use disposal equipment.

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Discourage risky behaviors e.g. tattooing, drug Discourage risky behaviors e.g. tattooing, drug

abuse and extramarital relations.abuse and extramarital relations.

Avoid transmission from persons with e antigen, Avoid transmission from persons with e antigen,

especially medical and dental personnel who especially medical and dental personnel who

routinely perform invasive procedures.routinely perform invasive procedures.

Health care personnel should follow the Health care personnel should follow the

universal precautions.universal precautions.