21/2/20101

2 Viral Hepatitis B (HBV) Associate Professor Family and Community Medicine Department King Saud University

21/2/20103 Serum hepatitis, serum jaundice.  Clinical signs & symptoms occur more in adults.  At least 50% of infections are asymptomatic  Onset is usually gradual with anorexia, nausea and vomiting, often progressing to jaundice.

21/2/20104 Incubation period: Average days Range days Clinical illness 5 yrs, 30%-50% Acute case-fatality rate: 0.5%-1% Chronic infection: 5 yrs, 2%-10% Premature mortality from chronic liver disease: 15%-25% Hepatitis B – Clinical Features

21/2/20105 Symptomatic Infection (%) 100 Symptomatic Infection Birth 1-6 mos 7-12 mos 1-4 yrs Older Children and Adults Symptomatic Infection of Hepatitis B Virus by Age at Infection

21/2/20106 Risk of Chronic HBV Carriage by Age of Infection

21/2/20107 Chronic Infection (%) Symptomatic Infection (%) 100 Symptomatic Infection Chronic Infection Birth 1-6 mos 7-12 mos 1-4 yrs Older Children and Adults Outcome of Hepatitis B Virus Infection by Age at Infection

21/2/20108 Chronic Hepatitis B Virus Infection Overall risk: 10% of all acute HBV infections.Overall risk: 10% of all acute HBV infections. About 15%-25% of persons with chronic HBV infection might die from either cirrhosis or liver cancer About 15%-25% of persons with chronic HBV infection might die from either cirrhosis or liver cancer Chronic HBV is theprimary cause of liver cancer. Chronic HBV is the primary cause of liver cancer. Chronic infection occurs in: Chronic infection occurs in: ~ 90% of infants infected with HBV at birth ~ 30% of children infected at age 1- 5 years 2- 6% of people infected after age 5 years

21/2/20109

10 High (>8%): High (>8%): –45% of global population – early childhood infections common Intermediate (2%-7%): Intermediate (2%-7%): –43% of global population – infections occur in all age groups Low (<2%): Low (<2%): –12% of global population – most infections occur in adult risk groups Global Patterns of Chronic HBV Infection

16/3/2009Dr. Salwa Tayel11 Agent Susceptible Host Reservoir Mode of transmission Cycle of infection Portal of Exit Portal of Inlet IP PC

21/2/ HBsAg Double-Stranded DNA HBsAg HBcAg HBeAg Hepatitis B Virus  The presence of HBsAg indicates active infection or chronic carrier.  Antibody to HBsAg, from either disease or vaccine, indicates immunity.

21/2/ Human (cases and carriers).  Human blood and blood products can transmit infection if not screened for HBs Ag.  Other body fluids have the virus with varying concentrations.

21/2/ Low/Not HighModerateDetectable semen serumvaginal fluid blood wound exudatessaliva urine feces sweat tears breast milk Concentration of HBV in Various Body Fluids

21/2/ Percutaneous: Unsafe injections and transfusions, organ transplants, sharing needles, haemodialysis, needle sticks, tattooing, razors and toothbrushes. 2.Perinatal exposure, especially when HBs Ag carrier mothers are also HBe Ag positive. 3.Sexual exposure.

21/2/ From days, average days. 1-2 months before the onset of symptoms during acute clinical course during the chronic carrier state which may persist for life.

21/2/  Prevent perinatal HBV transmission  Routine vaccination of all infants  Vaccination of children in high-risk groups  Vaccination of adolescents & all children up through age 18  Vaccination of adults in high-risk groups Strategy Elimination of HBV Transmission

21/2/ Licensed in 1982Licensed in 1982 Currently, subunit recombinant HBs AgCurrently, subunit recombinant HBs Ag given IM in the deltoid region.given IM in the deltoid region. 3 dose series, typical schedule 0, 1-2, 4-6 months - no maximum time between doses (no need to repeat missed doses or restart)3 dose series, typical schedule 0, 1-2, 4-6 months - no maximum time between doses (no need to repeat missed doses or restart) ProtectionProtection ~30-50% dose 1~30-50% dose 1 75% - dose 275% - dose 2 96% - dose 396% - dose 3 lower protection in older, immunosuppressive illnesses (e.g., HIV, chronic liver diseases, diabetes), obese, smokerslower protection in older, immunosuppressive illnesses (e.g., HIV, chronic liver diseases, diabetes), obese, smokers Hepatitis B Vaccine

21/2/ Routine for infants Routine for infants Ages “ catch up ”, and through age 18 years Ages “ catch up ”, and through age 18 years Over 18 – high risk Over 18 – high risk –Occupational risk health care workers (HCWs) –Hemodyalisis patients –All clinic clients of sexually transmitted diseases (STD) –Multiple sex partners or prior STD –MSM (Men having sex with men) –IDU (injecting drug users) –Institution for developmental disability (Staff & clients) Indication of Hepatitis B Vaccination

21/2/201020

21/2/ Prevention of perinatal HBV transmission Prevent perinatal HBV transmission by: screening all pregnant women for hepatitis B surface antigen (HBsAg) &screening all pregnant women for hepatitis B surface antigen (HBsAg) & At birth, providing hepatitis B immune globulin (HBIG) & andAt birth, providing hepatitis B immune globulin (HBIG) & and hepatitis B vaccine to infants of HBsAg ‑ positive mothershepatitis B vaccine to infants of HBsAg ‑ positive mothers

21/2/ Immunoglobulins (HBIG): (HBIG) is indicated in combination with the vaccine in:  needle stick injury  acute sexual exposure  perinatal transmission

21/2/ Other preventive measures  In blood banks: screening of blood donors And avoid donors from risky group.  Use of adequately sterilized syringes and needles or preferably use disposal equipment.

21/2/  Discourage risky behaviors e.g. tattooing, drug abuse and extramarital relations.  Avoid transmission from persons with e antigen, especially medical and dental personnel who routinely perform invasive procedures.  Health care personnel should follow the universal precautions.