Hepatitis C risk factors

• Intravenous drug users (IVDU)
• Blood transfusion before 1990

  • Current transfusion-associated risk: < 1/100,000
  • Comparative risks: Hepatitis B Virus (HBV) 1/63,000, HIV 1/493,000
  • Residual risk due to recently infected donors (10 week window)

• Percutaneous exposures

  • Needle stick transmission: ~3% HCV, 30% HBV, 0.3% HIV

• Lesser Risk Factors

  • High-risk sexual behavior
  • Low socioeconomic status (unclear mechanisms)

    • Sexual transmission inefficient
    • HIV coinfection increases sexual and maternal-fetal transmission

• Risk Factors For Progression

  • Alcohol use
  • HIV or HBV coinfection
  • Older age at infection, male sex

• Number of new infections per year has declined from an average of 240,000 in the 1980s to about 26,000 in 2004.
• Most infections are due to illegal injection drug use.
• Transfusion-associated cases occurred prior to blood donor screening; now occurs in less than one per 2 million transfused units of blood.
• Estimated 4.1 million (1.6%) Americans have been infected with HCV, of whom 3.2 million are chronically infected.
• The risk for perinatal HCV transmission is about 4%
• If coinfected with HIV the risk for perinatal infection is about 19%

References