The number of acute hepatitis C virus (HCV) cases reported to the U.S. Centers for Disease Control and Prevention (CDC) are just the “tip of the iceberg” when it comes to the overall burden of the liver disease. According to a new study published in the Annals of Internal Medicine, the actual number of people living with HCV could be 14 times higher than the published numbers, HealthDay News reports.

For the study, researchers analyzed data from a Massachusetts-based study of 183 patients diagnosed with acute hep C between 2001 and 2011. Of these patients, just one new HCV case was reported to the CDC. The remaining 182 cases went undisclosed to the agency, either because their test results didn’t come back fast enough or because they didn’t meet the CDC’s strict definitions of a “reportable” hep C case.

The CDC notes that the number of acute HCV cases reported to them by state health departments has tripled over the last few years, rising from 694 cases in 2005 to 2,138 in 2013. However, because of serious reporting troubles, experts estimate that the actual number of hep C cases ranges between 23,500 and 101,400 acute infections across the country.

Researchers said it was no surprise that so few cases are being reported, because most people who have acute hep C don’t get sick and because many people don’t test positive for HCV antibodies until months after they are infected. However, since three out of four acute hep C cases will eventually evolve into a chronic infection, which can lead to long-term liver damage and liver cancer, it’s important to know the right numbers.

The report underlines the importance of accurate data to inform future public health efforts to combat HCV.