Post on 26-Dec-2015
Prevention of Hepatitis B: the Foundation of Viral Hepatitis
Prevention
Harold S. Margolis, M.D.Division of Viral Hepatitis
National Center for Infectious DiseasesCenters 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)(millions) HIV HCV HBV
Africa 749 22.7 22.5 59.3Asia 3,585 7.3 107.5 286.8Latin America 504 1.7 15.1 10.3Europe 729 0.8 21.8 10.9Oceania 30 0.0 0.9 2.4North America 305 0.9 9.1 1.9Total 5,902 33.4 176.9 371.6
Chronic infections
Routes of Transmission andOpportunities for Prevention
of Infection with Hepatitis Viruses and HIV
Overlap Substantially
Risk Factors for Transmission of Hepatitis Viruses and HIV
Transfusion
Unknown
Occupational
Heterosexual partners MSM
Injection drug use
Risk Factor
Rare
30
5-7(past)
40
15
14
HBV
Past7- 20
10
<<1
20
1
60
HCV
9
Past2
<<1
10
47
31
HIV
Proportion of Infections (%)
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, Romania1997-1998
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
*Anti-HCV defined by EIA and supplemental testing
<0.1% - Very Low
>5% - High1.1-5% - Intermediate0.2-1% - Low
Unknown
Anit-HCV Prevalence *
Proportion of HCV Infections Attributable to Unsafe Injections
Case-Control Studies Population
Country Year Age Attributable %
Taiwan (Ho) 1993 Children 84%*(Chen) 1990-94 Adults 20%*(Sun) 1990 Adults 57%
Pakistan (Luby) 1994-95 All 51%*
Egypt (El Sakka) 1996-97 All 88%*
* Calculated from data provided by authorsSource: SIGN, WHO
Health-Care Procedures and HCV Infection
Low/Moderate Endemic Countries
Surgery DentalCountry HCV PosHCV Neg HCV PosHCV NegCase-Control USA 10% 12% 24%
24% Italy 17%* 2% 22%*
11%Cross-Sectional Italy 56%* 36% 91%*
80%77% 57% 90% 90%
Taiwan 13% 3% 24% 28% Pakistan No data 33% 39% Japan 32%* 10% No data
* P<.05, independent of other risk factors
Unsafe Injections and HCV Infection
Moderate Endemic Countries
History Reused Needles/Syringes
Country HCV Pos HCV Neg OR (95% CI)
Italy 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
0
10
20
30
40
50
0-9 10-19 20-29 30-39 40-49 50+
Age Group (Years)
Per
cen
t A
nti
-HC
V P
osi
tive Egypt
Japan, Italy
U.S., Australia
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
Attributable fraction 44% 36% 2%
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
Posttransfusion Hepatitis C
0
5
10
15
20
25
30
1965 1970 1975 1980 1985 1990 1995 2000
Year
% o
f Rec
ipie
nts
Infe
cted
All volunteer donors
HBsAg
Donor Screening for HIV Risk Factors
Anti-HIV
ALT/Anti-HBc
Anti-HCVImproved HCV Tests
Adapted from HJ Alter , et al . Clin Chem 1997
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 UsersBaltimore 1983–1988
0 6 12 18 24 30 36 42 48 54 60 66 720
20
40
60
80
100
Sero
pre
vale
nce (
%)
Duration of Injecting (months)
HCVHCV
HBVHBV
HIVHIV
Garfein RS. Am J Public Health. 1996;86:655.
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
Transfusion Other
Nosocomial
• Safe blood supply• Safe injections • Infection control
• Risk reduction services• Testing and counseling
SexualOther
Injection Drug Use
Low Endemicity
Relative Importance of Risk Factors for Hepatitis B and Prevention Strategies by
Endemicity
High/Moderate Endemicity
Nosocomial Other
Perinatal/Horizonal
• Infant Immunization • Safe blood supply• Safe injections • Infection control
• Infant, adolescent, adult immunization • Risk reduction services
Other Injection Drugs
Sex
Low Endemicity