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