Many U.S. patients living with the hepatitis C virus (HCV) are lost to care at different stages of the health care continuum, which prevents the majority of them from being cured, according to a new study by the American Association for the Study of Liver Diseases reported by Medical News Today.

Up to 75 percent of the estimated 3.2 million HCV-positive people in the United States are unaware of their status. Only about 27 percent are retained in care after their diagnosis, and only about 15 percent report getting treatment.

These estimates on the hep C treatment cascade are culled from the Philadelphia Department of Public Health’s hepatitis surveillance data, gathered between January 2010 and December 2013. The local data was then compared with data from the U.S. Census and the National Health and Nutrition Examination Survey.

Advocates are now calling for a greater effort to build HCV awareness among at-risk groups.