1Hepatitis B :A Clinical PerspectiveAdapted by Jill Gallin, CPNPAssistant Professor of Clinical NursingDecember, 2002Hepatitis B Overview• Serious: Causes death from liver disease in up to 25% of those infected at birth.• Cancer related: Liver cancer especially prevalent in areas of world where hepatitis B is common.• Disease of refugees: New arrival Southeast Asian refugees (1 out of 2 is immune, 1 out of 7 is a carrier, 1 out of 3 is susceptible).• Preventable: Safe, effective, and affordable vaccination is available.Geographic Distribution of Chronic HBV InfectionHBsAg Prevalence≥8% - High 2-7% - Intermediate <2% - LowHepatitis B Incidence in U.S., 2001• Estimated incidence• 78,000 cases/year• Reported cases• Acute hepatitis B: 7,844024681012141967 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000Year Cases per 100,000 PopulationSource: NNDSSVaccine licensedHBsAg screening of pregnant womenrecommendedOSHA rule enactedAdolescent Immunization recommendedDecline among MSM & HCWsDecline among injecting drug usersInfant immunizationrecommendedHepatitis B by Year, United States,1966 - 2000Transmission of HBV (1)• Concentration of HBV in various body fluids• High: Blood, serum, wound exudates• Medium: saliva, semen, and vaginal secretions• Low/not detectable: urine, feces, sweat, tears, breastmilk• Perinatal – transplacental transmission, rare (2-5%)• Sexual transmission – unprotected sex2Transmission of HBV (2)• Percutaneous transmission – sharing of injection drug use equipment, needle stick injury, ear-piercing, body piercing, tattooing, inadequate sterilization of medical equipment, scarification• Household and interhousehold transmission – less risk but significant - can occur in settings such as shared toothbrushes, razors, combs, washclothsTransmission of HBV (3)• Passed from child to child by biting, shared objects, oozing cuts, impetigo, etc. • Virus can exist on environmental surfaces for up to one week and remain infectious.• Pre-chewing food for babies, or sharing food that has been chewed by someone else (chewing gum).Transmission of HBV (4)• Institutionalized settings – risks of biting, sexual abuse• More than 1/4 of acute cases have no readily identifiable risk factor• Not spread by sneezing or coughing, sharing eating utensils.Risk Groups for HBV Infection (1)• Immigrants/refugees from areas of high HBV endemicity (Asia, Pacific Islands, Sub-Saharan Africa, Amazon Basin, E. Europe, Middle East) • Children born in U.S. to immigrants from areas of high HBV endemicity• Alaska Natives and Pacific Islanders • Household contacts and sex partners of people with chronic HBV infection Risk Groups for HBV Infection (2)• People who have or who have had sexually transmitted diseases• Heterosexuals with >1 sex partner in 6 months• Men who have sex with men• Users of illicit injectable drugs • Health care workers in contact with bloodRisk Groups for HBV Infection (3)• Adopted children from mod/high-risk countries• Hemodialysis patients• Recipients of certain blood products • Clients/staff at institutions for the developmentally disabled • Inmates of long-term correctional facilities3Hepatitis B Nomenclatureand/or Lab Tests (1)• HBV: Hepatitis B virus.• HBsAg: Hepatitis B surface antigen. Marker of infectivity when found in serum.• anti-HBs: Antibody to HBsAg. Marker of immunity when found in serum.• HBcAg: Hepatitis B core antigen. No commercial test available for this.• anti-HBc: Antibody HBcAg. Marker of past or current infection.• IgM anti-HBc: IgM is an antibody subclass of anti-HBc. Indicates recent infection with HBV (<4-6 mos.).• IgG anti-HBc: IgG is a subclass of anti-HBc. Indicates “older” infection with HBV.• HBeAg: Hepatitis B “e” antigen. Can only be present if HBsAg is positive. Marker of high degree of infectivity.• Anti-HBe: Antibody to “e” antigen. May be present in infected or immune person.Hepatitis B Nomenclatureand/or Lab Tests (2)• HBIG: Hepatitis B immune globulin. Passively delivered antibody that provides “instant” protection against HBV. • HCC/PHC: Hepatocellular carcinoma, primary hepatocellular carcinoma.• HDV: Hepatitis D virus (the delta virus). Etiologic agent of delta hepatitis. Can cause infection only in the presence of HBV infection.Hepatitis B Nomenclatureand/or Lab Tests (3)Hepatitis B: Clinical Features• Incubation period ranges from 45-180 days, average is 60-90 days • Onset is insidious• Clinical illness (jaundice): <10% for <5 yr olds30%-50% for >5 yrs • Acute case-fatality rate: 0.5%-1%• Chronic infection: <5 yrs old, 30%-90%>5 yrs old, 2%-6% • Premature mortality fromchronic liver disease: 15%-25%Acute Viral HepatitisSource: CDCSigns and Symptoms•Symptom• there may be none• loss of appetite, malaise, nausea, vomiting, abdominal pain, arthralgias, myalgias• Signs• there may be none• jaundice, fever, dark urine4Reported Cases of Hepatitis B, by Age, U.S., 1983-1998051015202519831985198719891991199319951997Year<15 years15-2425-3940+Source: NNDSSReported cases per 100,000 populationHBsAg negativeantiHBc negative susceptibleantiHBs negativeHBsAg negativeantiHBc positive immune due to natural infectionantiHBs positiveHBsAg positiveantiHBc positive acutely infectedIgM antiHBc positiveantiHBs negativeHBsAg positiveantiHBc positive chronicallyIgM antiHBc negative infectedantiHBs negativeInterpretation of Hepatitis B PanelHBsAg negativeantiHBc positive four possible interpretationsantiHBs negative (see next slide)HBsAg negativeantiHBc negative immune due to vaccineantiHBs positiveNatural History• Likelihood of becoming a carrier varies inversely with the age at which infection occurs. • Pool of carriers in U.S. is 1-1.25 million persons.• ~5000 persons die/yr. from HBV-related cirrhosis.Risk of Becoming Chronically Infected with HBV• 2% - 6% of older children and adults• 20% - 50% of children <5 yrs • 85% - 90% of infants infected at birthTreatment for HBV• Three FDA-licensed treatment options available for adults in the United States• interferon alfa-2b (IntronA), recombinant administered subcutaneously qd or 3x/wk¼ also licensed for use in children• lamivudine (Epivir-HB) administered by mouth qd• adefovir dipivoxil (Hepsera) administered by mouth qdConsult a liver specialist to assist in determining whether your patient is a treatment candidate.Monitoring HBsAg+ Patients•