The current estimate that about 2.7 million Americans are chronically infected with hepatitis C virus (HCV) may exclude about 800,000 people. Publishing their findings in the journal Hepatology, researchers considered that the estimated hep C prevalence, based on 2003 to 2010 data from the National Health and Nutrition Examination Survey (NHANES), excludes several high-risk populations, including individuals who are incarcerated, homeless, hospitalized, in a nursing home, in active-duty military service, or living on Native American reservations.

Data from NHANES suggest that 3.6 million Americans have antibodies for hep C, of whom 2.7 million are chronically infected. (Those who have antibodies but who are not chronically infected likely spontaneously cleared the virus without medical intervention.)

The researchers analyzed peer-reviewed literature as well as unpublished presentations and data in order to consider hep C prevalence among those populations NHANES does not include.

They estimated that 1 million individuals (between 0.4 million and 1.8 million) who were excluded from NHANES have antibodies for hep C, including 500,000 incarcerated people, 220,000 people who do not have a home, 120,000 people living on reservations, and 75,000 people in hospitals. Most of these individuals are likely men. An estimated 0.8 million (between 0.3 million and 1.5 million) of these people are chronically infected.

The investigators therefore estimate that at least 4.6 million (3.4 million to 6 million) Americans have hep C antibodies, with at least 3.5 million (2.5 million to 4.7 million) of them chronically infected.

To read the study abstract, click here.