As of 2019, the Centers for Disease Control and Prevention (CDC) requires over 100 diseases, infections and conditions – including hepatitis A, B and C – to be reported by state and local health departments. Physicians who diagnose these conditions, and diagnostic laboratories, are required to report confirmed and/or suspected cases to health departments, who then notify the CDC. This requirement allows the government to monitor disease patterns and track outbreaks to contain the spread of disease and protect the public. While all other forms of viral hepatitis are federally ‘reportable’, hepatitis delta cases are not required to be reported. Hepatitis delta is the most severe form of viral hepatitis, and spreads similarly to hepatitis B; through blood and sexual fluids, making it a public health threat, particularly for the 2.2 million people who already have hepatitis B in the U.S.