Defining the primary characteristics of persons infected with hepatitis C virus (HCV)
enables physicians to more easily identify persons who are most likely to benefit
from testing for the disease.
To describe the HCV-infected population in the United States.
Nationally representative household survey.
U.S. civilian, noninstitutionalized population.
15,079 participants in the National Health and Nutrition Examination Survey between
1999 and 2002.
All participants provided medical histories, and those who were 20 to 59 years of
age provided histories of drug use and sexual practices. Participants were tested
for antibodies to HCV (anti-HCV) and HCV RNA, and their serum alanine aminotransferase
(ALT) levels were measured.
The prevalence of anti-HCV in the United States was 1.6% (95% CI, 1.3% to 1.9%), equating
to an estimated 4.1 million (CI, 3.4 million to 4.9 million) anti-HCV-positive persons
nationwide; 1.3% or 3.2 million (CI, 2.7 million to 3.9 million) persons had chronic
HCV infection. Peak prevalence of anti-HCV (4.3%) was observed among persons 40 to
49 years of age. A total of 48.4% of anti-HCV-positive persons between 20 and 59 years
of age reported a history of injection drug use, the strongest risk factor for HCV
infection. Of all persons reporting such a history, 83.3% had not used injection drugs
for at least 1 year before the survey. Other significant risk factors included 20
or more lifetime sex partners and blood transfusion before 1992. Abnormal serum ALT
levels were found in 58.7% of HCV RNA-positive persons. Three characteristics (abnormal
serum ALT level, any history of injection drug use, and history of blood transfusion
before 1992) identified 85.1% of HCV RNA-positive participants between 20 and 59 years
Incarcerated and homeless persons were not included in the survey.
Many Americans are infected with HCV. Most were born between 1945 and 1964 and can
be identified with current screening criteria. History of injection drug use is the
strongest risk factor for infection.