Transcript Epidemiology and Prevention of Viral Hepatitis A to E:

Why we are here?
• However, a general lack of understanding
exists among health-care professionals
regarding the interpretation of screening
test results, when more specific testing
should be performed, and which tests
should be considered for this purpose.
Epidemiology and Prevention
of Viral Hepatitis A to E:
An Overview
Hepatitis Branch
Centers for Disease Control and Prevention
Viral Hepatitis - Historical Perspective
“Infectious”
Viral hepatitis
“Serum”
A
E
Enterically
transmitted
C
Parenterally
transmitted
NANB
B D
F, G,
? other
Viral Hepatitis - Overview
Type of Hepatitis
A
Source of
virus
Route of
transmission
Chronic
infection
Prevention
B
C
D
E
feces
blood/
blood/
blood/
blood-derived blood-derived blood-derived
body fluids
body fluids
body fluids
feces
fecal-oral
percutaneous percutaneous percutaneous
permucosal
permucosal
permucosal
fecal-oral
no
yes
pre/postexposure
immunization
pre/postexposure
immunization
yes
yes
blood donor
pre/postscreening;
exposure
risk behavior immunization;
modification risk behavior
modification
no
ensure safe
drinking
water
Acute Viral Hepatitis by Type, United States, 1982-1993
34%
47%
16%
3%
Source: CDC Sentinel Counties Study on Viral Hepatitis
Hepatitis A
Hepatitis B
Hepatitis C
Hepatitis
Non-ABC
Acute Hepatitis B Virus Infection with Recovery
Typical Serologic Course
Symptoms
anti-HBe
HBeAg
Total anti-HBc
Titer
0
4
anti-HBs
IgM anti-HBc
HBsAg
8
12
16
20
24
28
32
36
Weeks after Exposure
52
100
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
0
4
8 12 16 20 24 28 32 36
Weeks after Exposure
52
Years
Chronic Infection (%)
100
Outcome of Hepatitis B Virus Infection
by Age at Infection
100
80
80
60
60
Chronic Infection
40
40
20
20
Symptomatic Infection
0
Birth
1-6 months
7-12 months
Age at Infection
1-4 years
0
Older Children
and Adults
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
Geographic Distribution of Chronic HBV Infection
HBsAg Prevalence
³8% - High
2-7% - Intermediate
<2% - Low
Concentration of Hepatitis B Virus
in Various Body Fluids
High
Moderate
blood
serum
wound exudates
semen
vaginal fluid
saliva
Low/Not
Detectable
urine
feces
sweat
tears
breastmilk
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 11-12 years of age
– “high-risk” adolescents at all ages
• Vaccination of adults in high-risk groups
Suspicion of acute viral hepatitis based upon:
• History, physical exam, epidemiologic situation
•Elevated serum aminotransferase activity (ALT/AST)
Diagnosis:
Acute hepatitis A infection
Anti-HBc IgM positive
With or without HBsAg
Diagnosis:
Acute hepatitis B infection
Anti-HCV positive
Diagnosis: Acute HCV
infection or exacebation of
chronic HCV infection
‫براي تشخيص يا اثبات‬
‫اتيولوژي هپاتيت‬
Obtain viral serologies:
• Anti-HAV IgM
•HBsAg and Anti-HBc IgM
•Anti-HCV (EIA or RIBA)
Anti-HAV IgM positive
‫آزمايشات تكميلي‬
Negative serologies
Consider non-viral etiologies (e.g.,
Ischemia, toxins) or other infectious
Etiologies (e.g., CMV, EBV)
Check HBsAg and ALT/
AST in 6-9 months
Consider possibility of HEV
Infection if recent foreign
travel
Anti-HDV positive
HBsAg positive with or without
Abnormal aminotransferase
Re-check anti-HCV
In 3-6 months
Diagnosis: HBV/HDV
Co-infection
Diagnosis: Chronic
HBV infection
Suspicion of HDV co-infection based on:
• Risk factors (e.g., IVDA)
• Clinical signs of severe hepatities
Check anti-HDV
Can my baby die from hepatitis B?
• Most babies do not die from hepatitis B.
• Up to 9 out of 10 babies born to infected mothers will
end up being hepatitis B carriers for the rest of their
lives, if they do not get the shots.
carriers
• If you make sure your babies get all 3 shots, plus a
shot called H-BIG, they have a 95% chance of being
safe from hepatitis B for life.
Baby Shots
for Hepatitis B
if the mother has Hepatitis B
1 - 2 months old
Birth
Hepatitis B
Vaccine
+
Hepatitis B
Vaccine
H-BIG
6 months old
Hepatitis B
Vaccine
Hepatitis B can be prevented!
If you have never had hepatitis B,
you can get 3 shots . . .
1
2
3
. . . and get long lasting protection.
What if my baby does not
get these shots?
Up to 9 out of 10 babies born to infected
mothers will end up being carriers for the
rest of their lives, if they do not get the
shots.
Babies who end up as carriers have a 1 out
of 4 chance of dying from liver problems.
19 out of 20 babies who get the shots
will be protected for life!
Hepatitis D - Prevention
• HBV-HDV Coinfection
Pre or postexposure prophylaxis to prevent
HBV infection
• HBV-HDV Superinfection
Education to reduce risk behaviors among
persons with chronic HBV infection
Estimated Incidence of Acute Hepatitis B
United States, 1978-1995
Cases per 100,000 Population
80
Vaccine
licensed
70
HBsAg screening
Infant
of pregnant
immunization
women
recommended recommended
60
OSHA Rule
enacted
50
Adolescent
immunization
recommended
40
30
20
Decline
among
homosexual
men & HCWs
10
0
Decline among
injecting
drug users
*
78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95
* Provisional date
Year