VIRAL HEPATITIS B
The hepatitis B virus is a DNA virus belonging to
the Hepadnaviridae family of viruses.
VIRAL HEPATITIS TYPE B
Hepatitis B virus, HBV, Hepadnavirus, the so-called Dane particle with a
core (formed by DNA, DNA polymerase, and a nucleocapsid protein
with the hepatitis B core antigen (HBcAg) and a coat of hepatitis B
surface antigen (HBsAg) ). The whole virus is infectious with a
diameter of 42 nm.
Two months in the ende of incubation period, the sick or carriers.
Parenteral transmission - blood, blood products and inoculation of the
infectious material are of principal significance in the transmission.
Professional risk to medical personnel (injury by needle - transmission in 7 - 30
%, contaminated instruments, blood transfusions - transmission in 90 %).
i.v. drug addicts - injury during tattooing, possibly other minute injuries of the skin
and mucosa.
By sexual intercourse in homosexuals, bisexuals, and prostitutes.
Vertical - perinatal transmission from mother to child when the mother is the
virus carrier or the sick person. About 95 % of newborns infect intranatally and 5
% intrauterinely.
General
General
The source
of infection
Route of
transmission
Susceptibility
Etiology:
Preventive measures:
VIRAL HEPATITIS TYPE B
Preventive measures:
Health education - to emphasize the extent of risk
Observance of epidemic measures in medical establishments.
Handling biological material and contaminated instruments, consistent
disinfection and sterilization, application of single-use needles and
syringes, use of closed hemodialysis systems, smoking and drinking in
workplaces with biological material is forbidden.
Postexposure prophylaxis - passive and active immunization (newborns)
Examination of blood-donors - exclusion of HBsAg carriers from blood
donation
Designation and inspection of sanitary-epidemic measures in non-medical
establishments (hair-dressing salons, barber shops, etc.)
Active immunization in persons with a high risk of infection (stated by
public notice)
The disease occurs worldwide with a very high
burden among an estimated 280 million carriers.
The symptoms can vary greatly and many of those
infected with HBV never develop any symptoms at
all.
Those who do get symptoms (30-50% of cases)
usually suffer from tiredness, loss of appetite,
abdominal discomfort, nausea, vomiting and fever.
The vast majority of healthy adults who get acute
hepatitis B will recover with no liver damage in 4–
12 weeks but the death rate can reach 2% in the
elderly. Chronic infection is most likely to develop
in young babies.
The symptoms can vary greatly and many of those
infected with HBV never develop any symptoms at
all.
Those who do get symptoms (30-50% of cases)
usually suffer from tiredness, loss of appetite,
abdominal discomfort, nausea, vomiting and fever.
The vast majority of healthy adults who get acute
hepatitis B will recover with no liver damage in 4–12
weeks but the death rate can reach 2% in the
elderly.
Chronic infection is most likely to develop in young
babies.
• 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 from
chronic liver disease: 15%-25%
Hepatitis B – Clinical Features
Outcome of HBV Infection
Infection
Asymptomatic
Symptomatic
acute hepatitis B
Resolved
Immune
Chronic infection
Asymptomatic
Cirrhosis
Liver cancer
Resolved
Immune
Chronic
infection
Asymptomatic
Cirrhosis
Liver cancer
Weeks after Exposure
Symptoms
HBeAg anti-HBe
Total anti-HBc
IgM anti-HBc
anti-HBsHBsAg
0 4 8 12 16 20 24 28 32 36 52 100
Titer Acute Hepatitis B Virus Infection with Recovery
Typical Serologic Course
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
Weeks after Exposure
Progression to Chronic Hepatitis B Virus Infection
Typical Serologic Course
• Sexual
• Parenteral
• Perinatal
HBV Modes of Transmission
Low/Not
High Moderate Detectable
semen
serum vaginal fluid
blood
wound exudates saliva
urine
feces
sweat
tears
breast milk
Concentration of HBV
in Various Body Fluids
 Prevent perinatal HBV
transmission
 Routine vaccination of all
infants
 Vaccination of children in highrisk
groups
 Vaccination of adolescents
 all children up through age 18
 Vaccination of adults in highrisk
groups
Strategy
Elimination of HBV Transmission, United States
• Licensed in 1982; currently recombinant (in US)
• 3 dose series, typical schedule 0, 1-2, 4-6
months - no maximum time between doses (no
need to repeat missed doses or restart)
• 2 dose series (adult dose) licensed by FDA for
11-15 year olds (Merck)
• Protection ~30-50% dose 1; 75% - 2; 96% - 3;
lower in older, immunosuppressive illnesses
(e.g., HIV, chronic liver diseases, diabetes),
obese, smokers
Hepatitis B Vaccine
• Routine infant
• Ages 11-15 “catch up”, and through age 18(VFC
eligible)
• Over 18 – high risk
– Occupational risk (HCWs)
– Hemodyalisis patients
– All STD clinic clients
– Multiple sex partners or prior STD
– Inmates in Correctional settings
– MSM
– IDU
– Institution for developmental disability
• Pre-vaccination testing – if cost effective
• Post-vaccination testing – 1-2 months after last
shot, if establishing response critical (HCW)
Hepatitis B Vaccination
ACIP Recommendations