1 / 95

Epidemiology and Prevention of Viral Hepatitis A to E:

Epidemiology and Prevention of Viral Hepatitis A to E:. Hepatitis Branch Centers for Disease Control and Prevention. An Overview. Viral Hepatitis - Historical Perspective. Enterically transmitted. “Infectious”. A. E. Viral hepatitis. NANB. Parenterally transmitted. B. D. C.

uyen
Download Presentation

Epidemiology and Prevention of Viral Hepatitis A to E:

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Epidemiology and Prevention of Viral Hepatitis A to E: Hepatitis Branch Centers for Disease Control and Prevention An Overview

  2. Viral Hepatitis - Historical Perspective Enterically transmitted “Infectious” A E Viral hepatitis NANB Parenterally transmitted B D C “Serum” F, G, ? other

  3. Viral Hepatitis - Overview Type of Hepatitis A B C D E Source of feces blood/ blood/ blood/ feces virus blood-derived blood-derived blood-derived body fluids body fluids body fluids Route of fecal-oral percutaneous percutaneous percutaneous fecal-oral transmission permucosal permucosal permucosal Chronic no yes yes yes no infection Prevention pre/post- pre/post- blood donor pre/post- ensure safe exposure exposure screening; exposure drinking immunization immunization risk behavior immunization; water modification risk behavior modification

  4. Acute Viral Hepatitis by Type, United States, 1982-1993 34% 47% 16% Hepatitis A Hepatitis B Hepatitis C 3% Hepatitis Non-ABC Source: CDC Sentinel Counties Study on Viral Hepatitis

  5. Estimates of Acute and Chronic DiseaseBurden for Viral Hepatitis, United States HAV HBV HCV HDV Acute infections (x 1000)/year* 125-200 140-320 35-180 6-13 Fulminant deaths/year 100 150 ? 35 Chronic 0 1-1.25 3.5 infections million million 70,000 Chronic liver disease deaths/year 0 5,000 8-10,000 1,000 * Range based on estimated annual incidence, 1984-1994.

  6. Hepatitis A Virus

  7. Hepatitis A - Clinical Features • Incubation period: Average 30 days • Range 15-50 days • Jaundice by <6 yrs, <10%age group: 6-14 yrs, 40%-50% >14 yrs, 70%-80% • Complications: Fulminant hepatitis Cholestatic hepatitis Relapsing hepatitis • Chronic sequelae: None

  8. Age-specific Mortality Due to Hepatitis A Age group Case-Fatality (years) (per 1000) <5 3.0 5-14 1.6 15-29 1.6 30-49 3.8 >49 17.5 Total 4.1 Source: Viral Hepatitis Surveillance Program, 1983-1989

  9. Hepatitis A Virus Infection Typical Serologic Course Symptoms Total anti-HAV ALT Titer Fecal HAV IgM anti-HAV 4 5 6 12 24 0 1 2 3 Months after Exposure

  10. Concentration of Hepatitis A Virusin Various Body Fluids Feces Body Fluid Serum Saliva Urine 102 104 100 106 108 1010 Infectious Doses per ml Source: Viral Hepatitis and Liver Disease 1984;9-22 J Infect Dis 1989;160:887-890

  11. Hepatitis A Virus Transmission • Close personal contact(e.g., household contact, sex contact, child day care centers) • Contaminated food, water(e.g., infected food handlers, raw shellfish) • Blood exposure (rare)(e.g., injecting drug use, transfusion)

  12. Incidence of Hepatitis A, United States, 1952-1993 40 30 Rate (per 100,000) 20 10 0 1952 1960 1970 1980 1990 Year Source: CDC, National Notifiable Diseases Surveillance System

  13. Age-specific Incidence of Hepatitis A United States, 1983-93 25 20 15 5-14 years Reported Cases (per 100,000) 15-24 years 25-39 years 10 0-4 years 5 40+ years 0 1983 1984 1985 1987 1988 1989 1990 1991 1992 1993 1986 Year Source: CDC, National Notifiable Diseases Surveillance System

  14. Sources of Hepatitis A Virus Infection byMutually Exclusive Groups, United States, 1983-93 40 30 Personal contact Percentage of Cases 20 Day care center 10 Foreign travel Drug use Outbreak 0 1985 1987 1988 1989 1990 1991 1992 1993 1983 1984 1986 Year Source: CDC, Viral Hepatitis Surveillance Program

  15. Global Patterns of Hepatitis A Virus Transmission Disease Peak Age Endemicity Rate of Infection Transmission Patterns High Low to Early Person to person; High childhood outbreaks uncommon Moderate High Late Person to person; childhood/ food and waterborne young adults outbreaks Low Low Young adults Person to person; food and waterborne outbreaks Very low Very low Adults Travelers; outbreaks uncommon

  16. Geographic Distribution of HAV Infection Anti-HAV Prevalence High Intermediate Low Very Low

  17. Hepatitis A Vaccine Efficacy Studies Vaccine Site/Age Efficacy Vaccine Group N (95% CI) Ò HAVRIX Thailand 38,157 94% (SKB) 1-16 yrs (79%-99%) 2 doses 360 EL.U. ä VAQTA New York 1,037 100% (Merck) 2-16 yrs (85%-100%) 1 dose 25 units JAMA 1994;271:1363-4 N Engl J Med 1992;327:453-7

  18. Hepatitis A Vaccination Strategies Epidemiologic Considerations • Many cases occur in community-wide outbreaks • no risk factor identified for most cases • highest attack rates in 5-14 year olds • children serve as reservoir of infection • Persons at increased risk of infection • travelers • homosexual men • injecting drug users

  19. Routine Childhood Hepatitis A Vaccination • Benefits • established delivery system • vaccination before risk period • potential to interrupt transmission • Unresolved issues/considerations • immunogenicity in infants • development of combination vaccines • duration of protection • cost-effectiveness

  20. ACIP Recommendations - Hepatitis A Vaccine Preexposure Vaccination • Persons at increased risk for infection • travelers to intermediate and high HAV-endemic countries • homosexual and bisexual men • drug users • persons with chronic liver disease • Communities with high rates of hepatitis A(e.g., Alaska Natives, American Indians) • routine childhood vaccination

  21. Features of Community-wide Hepatitis A Outbreaks Usual Age Annual Type of Anti-HAV of Case- Incidence/ Outbreak Community Prevalence patients 100,000 Periodicity Populations High rate <5 yrs old 5-14 yrs 700-1000 5-10yrs well defined 30%-40% geographically >15 yrs old or ethnically 70% -100% Intermediate <5 yrs old 5-29 yrs 50-200 may be less defined rate 10%-25% periodic than in >15 yrs old high-rate <50% communities

  22. ACIP Recommendations - Hepatitis A Vaccine Control of Community-wide Outbreaks High-rate communities • Routine vaccination of young children • Accelerated catch-up vaccination of older children

  23. ACIP Recommendations - Hepatitis A Vaccine Control of Community-wide Outbreaks Intermediate-rate communities • Targeted vaccination can be considered for groups or areas with highest disease rates(e.g., specific age groups, census tracts,drug users) • Factors to consider: • feasibility of vaccinating target groups • program cost • ability to sustain vaccination of young children

  24. ACIP Recommendations - Hepatitis A Vaccine Prevaccination Testing • Considerations: • cost of vaccine • cost of serologic testing (including visit) • prevalence of infection • impact on compliance with vaccination • Likely to be cost-effective for: • adults born, or who lived in, high endemic areas • adults >40 years of age • older adolescents and young adults in certain groups(American Indians, Alaska Natives, Pacific Islanders)

  25. ACIP Recommendations - Hepatitis A Vaccine Postvaccination Testing • Not recommended because of the high response rate among vaccinees • No commercially available test to measure vaccine response

  26. Recommended Doses and Schedules of Hepatitis A Vaccine HAVRIXâ Doses No. Schedule Group Age Doses EL.U.* (ml) (months) Children and 3 360 (0.5) 0, 1, 6-12 adolescents 2-18 years Adults >18 years 2 1,440 (1.0) 0, 6-12 *ELISA units

  27. Hepatitis A Prevention - Immune Globulin • Preexposure • travelers to intermediate and high HAV-endemic regions • Postexposure (within 14 days) Routine • household and other intimate contacts Selected situations • institutions (e.g., day care centers) • common source exposure (e.g., food prepared by infected food handler)

  28. Hepatitis B Virus

  29. Hepatitis B - Clinical Features • Incubation period: Average 60-90 days • Range 45-180 days • Clinical illness (jaundice): <5 yrs, <10%³5 yrs, 30%-50% • Acute case-fatality rate: 0.5%-1% • Chronic infection: <5 yrs, 30%-90%³5 yrs, 2%-10% • Premature mortality fromchronic liver disease: 15%-25%

  30. Acute Hepatitis B Virus Infection with Recovery Typical Serologic Course Symptoms anti-HBe HBeAg Total anti-HBc Titer anti-HBs IgM anti-HBc HBsAg 0 4 8 12 16 24 28 32 52 100 20 36 Weeks after Exposure

  31. 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 Years 0 4 8 16 20 24 28 36 12 32 52 Weeks after Exposure

  32. Rate of Reported Hepatitis B by Age Group United States, 1990 25 20 15 Rate (per 100,000) 10 5 0 0-14 15-19 20-29 30-39 40+ Age Group (Years) Source: CDC Viral Hepatitis Surveillance Program

  33. Age at Aquisition of Acute and Chronic HBV Infection United States, 1989 Estimates (4% ) Perinatal (24%) (4%) Children (12%) (1-10 yrs) (8%) Adolescent (6%) Adult (59%) Adult (83%) Acute HBV Infections Chronic HBV Infections

  34. Outcome of Hepatitis B Virus Infection by Age at Infection 100 100 80 80 60 60 Chronic Infection Symptomatic Infection (%) Chronic Infection (%) 40 40 20 20 Symptomatic Infection 0 0 1-6 months 7-12 months Older Children and Adults Birth 1-4 years Age at Infection

  35. Global Patterns of Chronic HBV Infection • High (³8%): 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

  36. Geographic Distribution of Chronic HBV Infection HBsAg Prevalence ³8% - High 2-7% - Intermediate <2% - Low

  37. Concentration of Hepatitis B Virus in Various Body Fluids Low/Not High Moderate Detectable blood semen urine serum vaginal fluid feces wound exudates saliva sweat tears breastmilk

  38. Hepatitis B Virus Modes of Transmission • Sexual • Parenteral • Perinatal

  39. Risk Factors for Acute Hepatitis B United States, 1992-1993 Heterosexual* (41%) Injecting Drug Use (15%) Homosexual Activity (9%) Household Contact (2%) Health Care Employment (1%) Unknown (31%) Other (1%) * Includes sexual contact with acute cases, carriers, and multiple partners. Source: CDC Sentinel Counties Study of Viral Hepatitis

  40. Elimination of Hepatitis B Virus Transmission United States Objectives • Prevent chronic HBV Infection • Prevent chronic liver disease • Prevent primary hepatocellular carcinoma • Prevent acute symptomatic HBV infection

  41. 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

  42. Estimated Incidence of Acute Hepatitis B United States, 1978-1995 HBsAg screening of pregnant women recommended 80 Infant immunization recommended Vaccine licensed 70 60 OSHA Rule enacted 50 Cases per 100,000 Population Adolescent immunization recommended 40 30 20 * Decline among homosexual men & HCWs Decline among injecting drug users 10 0 78 79 81 82 83 84 85 87 88 89 90 91 92 93 94 95 80 86 Year * Provisional date

  43. Hepatitis C Prepared by Hepatitis Branch Centers for Disease Control and Prevention 9/25/00

  44. Features of Hepatitis C Virus Infection Incubation periodAverage 6-7 weeks Range 2-26 weeks Acute illness (jaundice)Mild (<20%) Case fatality rate Low Chronic infection75%-85% Chronic hepatitis70% (most asx) Cirrhosis10%-20% Mortality from CLD 1%-5%

  45. Chronic Hepatitis C Factors Promoting Progression or Severity • Increased alcohol intake • Age > 40 years at time of infection • HIV co-infection • ?Other • Male gender • Other co-infections (e.g., HBV)

  46. Serologic Pattern of Acute HCV Infection with Recovery anti-HCV Symptoms +/- HCV RNA Titer ALT Normal 6 1 2 3 4 0 1 2 3 4 5 Years Months Time after Exposure

  47. Serologic Pattern of Acute HCV Infection with Progression to Chronic Infection anti-HCV Symptoms +/- HCV RNA Titer ALT Normal 6 1 2 3 4 0 1 2 3 4 5 Years Months Time after Exposure

  48. Hepatitis C Virus Infection, United States New infections (cases)/year 1985-89 242,000 (42,000) 1998 40,000 (6,500) Deaths from acute liver failure Rare Persons ever infected (1.8%) 3.9 million (3.1-4.8)* Persons with chronic infection 2.7 million (2.4-3.0)* Of chronic liver disease - HCV-related 40% - 60% Deaths from chronic disease/year 8,000-10,000 .

  49. Estimated Incidence of Acute HCV InfectionUnited States, 1960-1999 Decline in injection drug users Decline in transfusion recipients Source: Hepatology 2000;31:777-82; Hepatology 1997;26:62S-65S

  50. Prevalence of HCV Infection United States, 1988-1994 Anti-HCV Est. Infections Percent of Group Positive millions (95% CI)Infections

More Related