Transcript Integrated Approaches for Prevention of Infections with

Prevention of Hepatitis B: the Foundation
of Viral Hepatitis Prevention
Harold S. Margolis, M.D.
Division of Viral Hepatitis
National Center for Infectious Diseases
Centers for Disease Control and Prevention
Atlanta, GA
Reasons to Combine
Viral Hepatitis and HIV/AIDS Prevention
• Major public health problems
• Routes of transmission overlap
• Effective prevention tools
– immunization, blood screening, universal precautions,
risk reduction, treatment
•
•
Well established programs for HIV/AIDS
Lack of integrated prevention activities leads to
transmission of both diseases, especially viral hepatitis
Hepatitis C: the tipping point for a new
direction in prevention
Estimated Number of Persons with
Chronic Bloodborne Virus Infections
1998
Region
Population
(millions)
Africa
749
Asia
3,585
Latin America
504
Europe
729
Oceania
30
North America
305
Total
5,902
Chronic infections
(millions)
HIV
HCV
HBV
22.7
22.5
59.3
7.3
107.5
286.8
1.7
15.1
10.3
0.8
21.8
10.9
0.0
0.9
2.4
0.9
9.1
1.9
33.4
176.9
371.6
Routes of Transmission and
Opportunities for Prevention
of Infection with
Hepatitis Viruses and HIV
Overlap Substantially
Risk Factors for Transmission of
Hepatitis Viruses and HIV
Proportion of Infections (%)
Risk Factor
HBV
HCV
HIV
Injection drug use
14
60
31
MSM
Heterosexual partners
15
1
47
40
20
10
Transfusion
Rare
Past
Past
7- 20
2
Occupational
5-7
<<1
<<1
10
9
Unknown
(past)
30
Prevention and Control of Viral
Hepatitis: its becoming more than
HBV infection
•
HAV, HBV and HCV infection are endemic in
most parts of the world, including the
independent states of the former Soviet Union.
•
First priority = prevention of HBV infection in
infants and young children = infant hepatitis B
immunization
•
Routine disease surveillance will identify
hepatitis B and hepatitis C in other age groups
Components of a Hepatitis B
Immunization Program
• Immunization
–
–
–
–
Infant
Catch-up for older children – ages defined by local epidemiology
Health care workers
Other high-risk adults – groups defined by local epidemiology
• Assessment of effectiveness of HepB immunization
– Vaccination coverage (age-specific)
– Population-based serologic assessment
– Acute disease surveillance
• Surveillance for Acute Viral Hepatitis
– All age groups
– Serologic conformation
– Risk factor data - immunization status, source of infection
A Model Hepatitis B Prevention
Program
• Immunization
–
–
–
–
infant
catch-up for older children
health care workers
other high-risk adults
• Prevent transfusion-transmitted infection - safe blood
and blood products
– screening of blood donors for HBsAg
– good manufacturing practices for blood products
– pooled products include virus inactivation
• Safe injection practices in all settings
• Infection control practices to prevent transmission of
•
bloodborne infections
Surveillance to assess prevention effectiveness
Injections among Unvaccinated Children < 5
years of age with Acute Hepatitis, Romania
1997-1998
Reported Cases
HBV
HAV
Cases
Controls
OR
95%CI
Received an injection
16
41
5.1
2.3-11
No injection
23
300
Ref
Population attributable risk among unvaccinated = 32%
Prevalence of HCV Infection in Blood
Donors
*
Anit-HCV Prevalence
>5% - High
1.1-5% - Intermediate
0.2-1% - Low
<0.1% - Very Low
Unknown
*Anti-HCV defined by EIA and supplemental testing
Proportion of HCV Infections
Attributable to Unsafe Injections
Case-Control Studies
Country
Year
Age
Children
Adults
Adults
Population
Attributable %
Taiwan (Ho)
(Chen)
(Sun)
1993
1990-94
1990
Pakistan (Luby)
1994-95
All
51%*
Egypt (El Sakka)
1996-97
All
88%*
* Calculated from data provided by authors
Source: SIGN, WHO
84%*
20%*
57%
Health-Care Procedures and HCV Infection
Low/Moderate Endemic Countries
Country
Case-Control
USA
Italy
Cross-Sectional
Italy
Taiwan
Pakistan
Japan
Surgery
HCV Pos HCV Neg
10%
17%*
12%
2%
56%*
36%
77%
57%
13%
3%
No data
32%*
10%
* P<.05, independent of other risk factors
Dental
HCV Pos HCV Neg
24%
22%*
24%
11%
91%*
80%
90%
90%
24%
28%
33%
39%
No data
Unsafe Injections and HCV Infection
Moderate Endemic Countries
Country
Italy
History Reused Needles/Syringes
HCV Pos HCV Neg OR (95% CI)
63%
31%
3.8 (2.7, 5.3)
89%
53%
7.0 (4.4, 11.2)
76%
72%
1.2 (0.6, 2.5)
Taiwan
26%
8%
4.2 (1.2, 14.5)
Pakistan (>5/yr)
36%
6%
8.2 (1.9, 41.4)
Geographic Patterns of Age-Specific
Prevalence of HCV Infection
Egypt
Percent Anti-HCV Positive
50
40
30
20
Japan, Italy
10
U.S., Australia
0
0-9
10-19
20-29
30-39
Age Group (Years)
40-49
50+
Burden of Disease Attributable to Unsafe
Injections, Developing and Transitional
Economy Countries, Preliminary Data
HCV
HBV
HIV
Total number of
infections
4.8 m
64.7 m
5.5 m
Infections attributable to
unsafe injection
2.1 m
23.0 m
0.1 m
44%
36%
2%
Attributable fraction
Source: Armstrong, Hauri, Hutin
Posttransfusion Hepatitis in
Developing Countries
•
Inappropriate use of blood and blood products –
single unit transfusions common
•
Lack of organized transfusion services
•
Most transfused units not tested for HBV or HCV
•
Related donors often used – perception that less
likely to be infected
•
Paid donors continue to be used in many
countries
% of Recipients Infected
Posttransfusion Hepatitis C
30
All volunteer donors
HBsAg
25
20
15
Donor Screening for HIV Risk Factors
Anti-HIV
ALT/Anti-HBc
10
Anti-HCV
Improved HCV Tests
5
0
1965
1970
1975
1980
1985
Year
Adapted from HJ Alter , et al . Clin Chem 1997
1990
1995
2000
Injecting Drug Use: HBV and HCV
Infection
•
•
•
•
•
•
Highly efficient mode of transmission
Rapidly acquired after initiation
Four times more common than HIV
Prevalence 50-90% after 5 years
Predominant risk factor in low prevalence countries
Emerging risk factor in medium prevalence countries
–acute hepatitis B and hepatitis C in adults are often
the best indicator of injection drug use problem
Risk of Bloodborne Virus Infections
Injection Drug Users
Baltimore 1983–1988
Seroprevalence (%)
100
HCV
80
HBV
60
40
HIV
20
0
0
6
12
18
24
30
36
42
48
54
Duration of Injecting (months)
Garfein RS. Am J Public Health. 1996;86:655.
60
66
72
Injecting Drug Use and HCV Infection
High/Moderate Endemic Countries
• Minor role in the distant past
•
Highest incidence of hepatitis C now seen in young
adults in some countries (e.g., Italy, Japan)
– sentinel event for emergence of injecting drug use
• History of injecting drug use becoming more common
– 50% of persons with acute hepatitis C (Italy, Russia)
– 40% of HCV-positive persons <40 yrs old vs. 0% >40
(Italy)
– 2/3 of HCV-positive commercial blood donors (Egypt)
Relative Importance of Risk Factors for
Hepatitis C and Prevention Strategies by
HCV Endemicity
High/Moderate Endemicity
Nosocomial
Transfusion
Low Endemicity
Injection Drug Use
Other
• Safe blood supply
• Safe injections
• Infection control
Other
Sexual
• Risk reduction services
• Testing and counseling
Relative Importance of Risk Factors for
Hepatitis B and Prevention Strategies by
Endemicity
High/Moderate Endemicity
Perinatal/Horizonal
Nosocomial
Other
• Infant Immunization
• Safe blood supply
• Safe injections
• Infection control
Low Endemicity
Sex
Injection Drugs
Other
• Infant, adolescent, adult
immunization
• Risk reduction services