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)