Hepatitis B

Basics

Description

Hepatitis B infection (HBV), caused by a DNA virus, is often transmitted by body fluids (blood, semen, and vaginal secretions). HBV is a serious global health care concern due to the spectrum of liver disease; it can cause ranging from acute hepatitis to cirrhosis and/or hepatocellular carcinoma (HCC).

Epidemiology

Incidence

  • Infects patients of all ages; 80% of cases are in persons aged 30 to 59 years (1).
  • Predominant sex: fulminant HBV: male > female (2:1)
  • ~60,000 new cases annually in the United States (2)
  • Lower incidence in the United States compared to Asia and Africa due to better access to health care, use of vaccinations, and preventive measure

Prevalence

  • In the United States, 1.59 million persons (range: 1.25 to 2.49 million) with chronic HBV (3)
  • Asia, the Pacific Islands, and people born in Africa have the largest populations at risk
  • Chronic HBV worldwide: 350 to 400 million persons
    • Second most important carcinogen (behind tobacco)
    • Of chronic carriers with active disease, 25% die due to complications of cirrhosis or HCC.

Etiology and Pathophysiology

HBV is a DNA virus of the Hepadnaviridae family; two modes of transmission:

  • Horizontal: mucosal surface contact with infectious bodily fluids
  • Vertical: maternal-to-newborn perinatal

Genetics
Family history of HBV and/or HCC

Risk Factors

  • Screen the following high-risk groups for HBV with HBsAg. If positive, test for antibodies to HBsAg (anti-HBs) and hepatitis B core antigen (anti-HBc) to distinguish between infection and immunity. Vaccinate if seronegative (4):
    • Household or sexual contacts with hepatitis B; persons born in regions with increase prevalence (Asia, Africa, Eastern Europe); HIV- and HCV-positive patients
    • Persons born in the United States who were not vaccinated as infants or whose parents are from regions of high prevalence
    • Individuals with chronic liver disease; pregnant women; residents in carceral facilities
  • Additional risk factors:
    • Donors and recipients of blood/products; persons on hemodialysis or immunosuppressive therapy; needle stick/occupational exposure; intranasal drug use; body piercing/tattoos; survivors of sexual assault; infants born to mothers positive for hepatitis B surface antigen

Pediatric Considerations

  • Shorter acute course; fewer complications
  • 90% of vertical/perinatal infections become chronic.

Pregnancy Considerations

  • Screen for HBsAg at first prenatal visit (4)[A].
  • If HBsAg (+), obtain HBV DNA.
  • Consider treating patients with high viral load at 28 weeks or history of previous HBV (+) infant with oral nucleos(t)ide medication beginning at 32 weeks to reduce perinatal transmission. Infants born to HBV-infected mothers require hepatitis B immune globulin (HBIg) and HBV vaccine within 12 hours of birth, completing the vaccine series and serologic testing for infection and immunity by 9 to 12 months.
  • Breastfeeding is safe if HBIg and HBV vaccines are administered and the areolar complex is without fissures or open sores. Avoid oral nucleos(t)ide medications during lactation.
  • HIV increases risk of vertical transmission. Continue medications if pregnancy occurs while on an oral antiviral therapy to prevent acute flare.

General Prevention

  • Vaccination
    • Three IM injections at 0, 1, and 6 months in infants or healthy adults
    • Indicated for all medically stable infant weighing ≥2,000 g (4 lb, 6 oz) within 24 hours of birth; unvaccinated infants, children, and adults; all at-risk patients; health care and public safety workers; sexual contacts; and household contacts of HBsAg carriers
    • CDC does not recommend administration of >2 complete hepatitis B series except for certain cases related to patients on hemodialysis.
  • Other preventive measures
    • Proper hygiene/sanitation by health care workers, IVDUs, and tattoo/piercing artists; barrier precautions, needle disposal, sterilize equipment, cover open cuts; do not share personal items exposed to blood (e.g., nail clipper, razor, toothbrush).
    • Safe sexual practices (condoms)
    • HBsAg carriers cannot donate blood or tissue.
    • Postexposure (e.g., needle stick):
      • HBIg 0.06 mL/kg in <24 hours in addition to vaccination (no more than 7 days after exposure)
      • Second dose of HBIg should be administered 30 days after exposure.

Commonly Associated Conditions

  • HIV, hepatitis C coinfection
  • Extrahepatic manifestations include:
    • Serum sickness-like syndrome (fever, erythematous rash, myalgias, arthralgias, fatigue); glomerulonephritis (membranous or membranoproliferative glomerulonephritis, IgA-mediated nephropathy)
    • Polyarteritis nodosa (primary systemic necrotizing vasculitis, high fever, weakness, malaise, loss of weight and appetite); dermatologic conditions (bullous pemphigoid, lichen planus, Gianotti-Crosti syndrome); cryoglobulinemia (Raynaud phenomenon, arthritis, sicca syndrome)
    • Neurologic/psychological condition (Guillain-Barré syndrome, altered mental status, depression/psychosis)

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