Hepatitis B :
A Clinical Perspective
| 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. |
Hepatitis B Incidence
in U.S., 2001
| Estimated incidence | ||
| 78,000 cases/year | ||
| Reported cases | ||
| Acute hepatitis B: 7,844 | ||
| 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 sex | ||
| 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, washcloths |
| 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). |
| 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 blood | |
Risk 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 facilities |
Hepatitis B
Nomenclature
and/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. |
Hepatitis B
Nomenclature
and/or Lab Tests (2)
| 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
Nomenclature
and/or Lab Tests (3)
| 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. |
| Symptom | ||
| there may be none | ||
| loss of appetite, malaise, nausea, vomiting, abdominal pain, arthralgias, myalgias | ||
| Signs | ||
| there may be none | ||
| jaundice, fever, dark urine | ||
| 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 birth | |
| Three FDA-licensed treatment options available for adults in the United States | |||
| interferon alfa-2b (IntronA), recombinant administered subcutaneously qd or 3x/wk | |||
| also licensed for use in children | |||
| lamivudine (Epivir-HB) administered by mouth qd | |||
| adefovir dipivoxil (Hepsera) administered by mouth qd | |||
| Consult a liver specialist to assist in determining whether your patient is a treatment candidate. |
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| Discuss monitoring with a liver specialist having much experience in managing viral liver diseases. | ||
| Annual physical exam. | ||
| Blood work every 6-12 mos. | ||
| Liver biopsy? | ||
| Liver ultrasound or CT scan every 6-12 mos. | ||
| "fetoprotein (AFP) every 6-12 mos. | ||
| Education of patient about disease. | ||
Management of Family Members of HBsAg+ Patients
| Test all family members with hepatitis B panel (HBsAg, antiHBc, antiHBs) | |
| For those susceptible, vaccinate | |
| For susceptible sex partner(s), test after 3 doses to be sure s/he converts to antiHBs+ | |
| Education of family members |
This Khmer woman died
of hepatoma, four months after arriving in a refugee camp in Thailand.
Hepatocellular Carcinoma – HCC (1)
| HBV leads to liver cancer | ||
| epidemiologic correlation in many populations | ||
| risk for HCC is 12-300 times greater in HBsAg+ persons | ||
| HBV DNA is incorporated into DNA of hepatoma cells | ||
| Incidence | ||
| peak incidence is in 40-60 yr olds | ||
| in Taiwan, #1 cause of death for men >40 yrs | ||
| 0.25-1 million deaths/year in the world | ||
| over 1500 persons die/yr in the U.S. from HCC | ||
| HCC is 3-4x more common in HBsAg+ men than women | ||
| Hepatitis B Immune Globulin (HBIG) | ||||
| provides temporary passive protection | ||||
| indicated in certain postexposure settings | ||||
| Hepatitis B Vaccine | ||||
| vaccinate all children 0-18 years of age | ||||
| infant schedule: birth dose preferred (0, 1-2, 6), (0, 1-4, 6-18) | ||||
| Schedule if using monovalent vaccine
followed by Comvax ®: (0, 2, 4, 12) |
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| children/teens: (0, 1, 6), ( 0, 1-2, 4)
(0, 1, 6-12) or (0, 12, 24) month schedule. There is also a two-dose schedule
for 11-15 year olds using Recombivax HB ® only. This schedule is
0, 4-6 months. |
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| Hepatitis B Vaccine (continued) | |||
| Vaccinate all high-risk individuals | |||
| Adult schedule (0, 1-2, 6) | |||
| Testing can be done if concern that patient has been previously infected, but do not delay administering first dose of vaccine until a later visit; test, then give first dose. | |||
| Hepatitis B Prenatal Testing | |||
| Test EVERY pregnant woman during every pregnancy for HBsAg, even if she has been immunized against hepatitis B or is chronically infected. | |||
| Send a copy of the original lab report to the hospital. | |||
Prevention Schedule for Infants of HBsAg-POSITIVE Mothers
| HBIG 0.5 ml IM within 12 hrs. of birth. | ||
| Dose #1 of Hep B vaccine in the opposite thigh within 12 hrs. of birth. | ||
| Dose #2 of Hep B vaccine at 1-2 mos. | ||
| Dose #3 of Hepatitis B vaccine at 6 mos. | ||
| Testing for antiHBs and HBsAg 9-15 mos. | ||
| If negative for both, repeat the series and test 1–2 months later! | ||
Schedule for infants of mothers with UNKNOWN HBsAg status
| Test mother for HBsAg in hospital ASAP. | |
| If mother’s test is positive, give HBIG ASAP (within 7 days of birth). | |
| Give dose #1 of Hep B vaccine within 12 hrs. of birth. DO NOT DELAY THIS DOSE waiting for the lab result. | |
| Dose #2 of Hep B vaccine at 1-2 mos. | |
| Dose #3, follow dosing schedule based on mother’s HBsAg status. |
Schedule for infants with
HBsAg-NEGATIVE mothers
| Dose #1 recommended to be given at birth. | ||
| Dose #2 can be given at 1-4 mos. of age | ||
| Dose #3 at 6-18 mos. of age | ||
| Final dose should NOT be given before
age 6 mos. |
||
| May also give monovalent hepatitis B #1
at birth followed by 3 does of Comvax ® at 2, 4, and 12-15 mos., or 3 doses of Pediarix ® at 2, 4, and 6 mos. |
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Dosing schedule for older
children
and teens (NOT INFANTS)
| Rule #1: There must be at least 4 wks. between dose #1 and dose #2. | |
| Rule #2: There must be at least 8 wks. between dose #2 and dose #3. | |
| Rule #3: There must be at least 4 mos. between dose #1 and dose #3. | |
| Rule #4: No matter how delayed dose #2 or #3 is, do not start the series over again. | |
| Suggested spacing options: 0, 1-2, 4-6
mos.; 0, 2, 12 mos.; 0, 12, 24 mos. |
| 0, 1, 6 month interval is standard for HCWs | ||
| Space dose #1 and #2 four wks. apart | ||
| Space dose #2 and #3 five mos. apart | ||
| Alternative schedules 0, 2, 4; 0, 1, 4 | ||
| Never re-start the series if dosing was delayed. Continue from where you left off. | ||
| Use a 1” or 1.5” needle. If obese, use 2”. | ||
| Injection must be intramuscular in deltoid. | ||
Recommended post-exposure
prophylaxis
for exposure to HBV
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 |
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 | ||
AAP, AAFP, and ACIP Recommend Hepatitis B “Catch-up”
| Give hepatitis B vaccine to all children 0-18 y.o. | |
| “Providers should make special efforts”
to catch-up children (of parents) from moderate/high risk endemic areas. |
| Remember… | |
| You should never start the | |
| hepatitis B vaccine series over again,
no matter how long each dose is delayed! |
| Deborah L. Wexler, MD | |
| Executive Director | |
| Immunization Action Coalition | |
| www.immunize.org |