Hepatitis  D and E represent a group of lesser-known viral hepatitis infections that vary widely in how they spread, who they affect and the health challenges they pose. Learning about less common types of hepatitis helps you take steps to stay safe, like practicing good hygiene, talking to your healthcare provider before traveling and getting vaccinated.
Healthcare providers interested in learning more can take the CDC's training on viral hepatitis serology, which covers all types of viral hepatitis.
Hepatitis D
Hepatitis D, also known as "hepatitis delta," is a liver infection caused by the hepatitis D virus (HDV). HDV can cause severe symptoms and serious illness that can lead to liver damage and even death. Hepatitis D is uncommon in the United States, and only occurs among people who are infected with the hepatitis B virus (HBV). Hepatitis D is an incomplete virus that uses the hepatitis B virus to replicate itself and make you sick. This means that you can only get hepatitis D if you have hepatitis B.
HDV can be an acute short-term infection or a long-term chronic infection. You can only get hepatitis D after coming into contact with the blood or body fluids of someone who is infected with HDV. Getting vaccinated for hepatitis B provides protection against both hepatitis B and hepatitis D.
For more information on hepatitis D, you can visit Hepatitis Delta Connect.
Coinfection or Superinfection
People with hepatitis D can become infected with both HBV and HDV at the same time or get hepatitis D after first being infected with HBV.
- Coinfection: People who get infected with both HBV and HDV at the same time are considered coinfected. Coinfection with HBV and HDV can cause serious short-term health problems and even liver failure, but it usually does not lead to lifelong illness.
- Superinfection: When people get hepatitis D after first having been infected with HBV, it is called a superinfection. This type of infection is more likely to result in long-term illness, including rapid development of liver fibrosis, liver failure and even death.
Hepatitis E
Hepatitis E is a liver infection caused by the hepatitis E virus (HEV). Hepatitis E is a self-limited disease that does not usually result in a chronic infection. Pregnant women, adults over 65 years of age, young children and people with poor immune systems are at a higher risk for a chronic infection. Most people recover without any issues.
While rare in the United States, hepatitis E is common in many parts of the world. It is transmitted from ingestion of fecal matter, even in microscopic amounts, and is associated with a contaminated water supply in countries with poor sanitation. Most cases in the United States are not domestically acquired, meaning they are related to international travel. Some people will not have any symptoms or know that they are sick. If symptoms occur, they can appear anywhere from two to six weeks after exposure to HEV. There is not a vaccine for hepatitis E.
For more information on hepatitis E, you can read the CDC's Basics of Hepatitis E.