Acute hepatitis C in a contemporary US cohort: modes of acquisition and factors influencing viral clearance

J Infect Dis. 2007 Nov 15;196(10):1474-82. doi: 10.1086/522608. Epub 2007 Oct 31.


Background: Acute hepatitis C virus (HCV) infection is often asymptomatic; thus, its epidemiology and natural history are difficult to define.

Methods: Acute HCV infection was identified on the basis of HCV seroconversion within 1 year (n=45), new anti-HCV seropositivity with clinical acute hepatitis (n=21), or HCV strain sequencing after an iatrogenic exposure (n=1). Risk factors were assessed with a baseline questionnaire, and participants were followed up prospectively with serial measurement of viral loads.

Results: Of 67 persons with acute HCV infection, most were asymptomatic (64%) and injection drug users (66%). Thirteen had an unknown mode of transmission; of these, 11 reported high-risk sexual behavior. Ten acquired acute HCV infection within 3 months of an iatrogenic exposure; 3 had confirmed iatrogenic infection, and 4 had no other risk factors identified. The spontaneous viral clearance rate after 6 months of infection was 18% (95% confidence interval, 11%-31%). The rate of viral clearance varied significantly by sex (34% vs. 3% for women vs. men; P<.001).

Conclusions: High-risk sexual or iatrogenic exposures may be important contemporary risk factors for HCV infection. The spontaneous viral clearance rate (18%) in this contemporary study was similar to that reported for past studies of transfusion-associated HCV infection. Women were more likely to clear acute HCV infection than men.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adolescent
  • Adult
  • Age Distribution
  • Aged
  • Aged, 80 and over
  • Antibodies, Viral / blood
  • Cohort Studies
  • Disease Transmission, Infectious*
  • Female
  • Hepacivirus / genetics
  • Hepacivirus / immunology
  • Hepacivirus / isolation & purification*
  • Hepatitis C / blood
  • Hepatitis C / epidemiology*
  • Hepatitis C / etiology
  • Hepatitis C / prevention & control
  • Hepatitis C / transmission*
  • Humans
  • Immunoglobulin M / immunology
  • Male
  • Middle Aged
  • Polymerase Chain Reaction
  • RNA, Viral / analysis
  • Risk Factors
  • Sex Factors
  • Sexual Behavior
  • Surveys and Questionnaires
  • United States / epidemiology
  • Viral Load
  • Viremia


  • Antibodies, Viral
  • Immunoglobulin M
  • RNA, Viral