Hepatitis A is an acute liver disease caused by the hepatitis A virus (HAV), lasting from a few weeks to several months. It does not lead to chronic infection.

Transmission: Ingestion of fecal matter, even in microscopic amounts, from close person-to-person contact or ingestion of contaminated food or drinks.

Vaccination: Hepatitis A vaccination is recommended for all children starting at age 1 year, travelers to certain countries, and others at risk.

Hepatitis B is a liver disease caused by the hepatitis B virus (HBV). It ranges in severity from a mild illness, lasting a few weeks (acute), to a serious long-term (chronic) illness that can lead to liver disease or liver cancer.

Transmission: Contact with infectious blood, semen, and other body fluids from having sex with an infected person, sharing contaminated needles to inject drugs, or from an infected mother to her newborn.

Vaccination: Hepatitis B vaccination is recommended for all infants, older children and adolescents who were not vaccinated previously, and adults at risk for HBV infection.

Hepatitis C is a liver disease caused by the hepatitis C virus (HCV). HCV infection sometimes results in an acute illness, but most often becomes a chronic condition that can lead to cirrhosis of the liver and liver cancer.

Transmission: Contact with the blood of an infected person, primarily through sharing contaminated needles to inject drugs.

Vaccination: There is no vaccine for hepatitis C.

Hepatitis D is a serious liver disease caused by the hepatitis D virus (HDV) and relies on HBV to replicate. It is uncommon in the United States.

Transmission: Contact with infectious blood, similar to how HBV is spread.

Vaccination: There is no vaccine for hepatitis D.

Hepatitis E is a serious liver disease caused by the hepatitis E virus (HEV) that usually results in an acute infection. It does not lead to a chronic infection. While rare in the United States, hepatitis E is common in many parts of the world.

Transmission: Ingestion of fecal matter, even in microscopic amounts; outbreaks are usually associated with contaminated water supply in countries with poor sanitation.

Vaccination: There is currently no FDA-approved vaccine for hepatitis E.