Description

Systemic viral infection that may cause acute and chronic liver disease and hepatocellular carcinoma (HCC)

Epidemiology

• Predominant age: All ages
• Predominant sex: Fulminant hepatitis B virus (HBV): Male > Female (2:1)
• In the US, estimated 38,000 new infections in 2009, 70% due to IV drug use
• African Americans: Highest rate of acute HBV infection in the US
• Overall rate of new infections down 82% since 1991 (due to national immunization strategy)

• In the US, 800,000–1.4 million people have chronic HBV.
• Asia and the Pacific Islands have the largest populations at risk for HBV.
• Chronic HBV worldwide: 350–400 million persons:
  • Per year: 1,000,000 deaths:
    • 2nd most important carcinogen (behind tobacco)
    • Of chronic carriers, 25% die of cirrhosis or HCC.
    • Of chronic carriers, 75% are Asian.

Risk Factors

• Screen high-risk groups with HBsAg/sAb (1)[A]:
  • Persons born in endemic areas (45% of world)
  • Hemodialysis patients
  • IV drug users (IVDU), past or present
  • Men who have sex with men (MSM)
  • HIV- and HCV-positive patients
  • Household members of HBsAg carriers
  • Sexual contacts of HBsAg carriers
  • Inmates of correctional facilities
  • Patients with chronically elevated ALT/AST
• Vaccinate all above groups if negative.
• Additional risk factors:
  • Needle stick/occupational exposure
  • Recipients of blood/products; transplanted organ recipients
  • Intranasal drug users
  • Body piercing/tattoos

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

• Screen all pregnant women for HBsAg (1)[A].
• High viral load at 28 weeks should prompt consideration for treatment with oral nucleos(t)ide meds from 32 weeks to reduce perinatal transmission.
• Infant of HBV-infected mother needs HB immune globulin (HBIg) (0.5 mL) plus HBV vaccine within 12 hours of birth and HBV series at 0, 1, and 6 months (1)[A].
• Breast-feeding is safe if HBIg and HBV vaccine are administered and nipples are without fissures. Oral nucleos(t)ide medications are not recommended in lactating mothers. Risk and benefits must be assessed.
• HIV coinfection significantly increases risk of vertical transmission.
• Continue medications if pregnancy occurs while on an oral antiviral therapy to prevent acute flare.

General Prevention

Most effective: HBV vaccination series (3 doses):

• Vaccinate:
  • All infants at birth
  • All at-risk patients (see “Risk Factors”)
  • Health care and public safety workers
  • Sexual contacts of HBsAg carriers
  • Household contacts of HBsAg carriers
• Proper hygiene/sanitation by health care workers, IVDU, and tattoo/piercing artists:
  • Barrier precautions, needle disposal, sterilization of 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., needlestick): HBIg 0.06 mL/kg in <24 hours and vaccination

Etiology

HBV is a DNA virus of the family Hepadnaviridae.

Commonly Associated Conditions

Arthritis, polyarteritis nodosa, membranous glomerulopathy, anemia (including aplastic anemia), dermatitis, cardiomyopathy, hepatitis D virus infection, metabolic syndrome