Before 1992, blood used in transfusions during emergency and surgical procedures was not tested for viruses. Widespread screening of blood donations didn’t start happening until 1992, meaning those who donated before then could have also been donating more than just their blood – they could have shared diseases like hepatitis c. That’s why the Centers for Disease Control are now asking all Americans in the baby boomer generation to get tested for this potentially liver-destroying disease.

Only about a quarter of those infected with Hep C are able to fight it off naturally, without medical treatment. The rest are suffering from a serious infection, potentially without their knowledge. The virus can gradually scar the liver and lead to cirrhosis or liver cancer, and is the leading cause of liver transplant. It can trigger damage in other parts of the body as well. All told, more than 15,000 Americans die each year from hepatitis C-related illnesses, according to the CDC.