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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