HEPATITIS A

Usually spread by: Food or drink that has been contaminated with human excrement. Most common in parts of the world where hygiene is poor.

Prevention: Hepatitis A vaccine – for people traveling to certain areas of the world and for those at risk due to certain medical conditions.

HEPATITIS B

Usually spread by: Unprotected sex with an infected person or IV drug use involving infected blood. Highly contagious.

Prevention: Hepatitis B vaccine – since 1991, among the recommended childhood immunizations.

HEPATITIS C

Usually spread by: Direct blood contact with an infected person (IV drug use, blood transfusion before widespread screening began around 1992, contaminated needles used in tattooing, body piercing, etc.). Often has no symptoms until liver damage has occurred. The leading reason for liver transplants.

Prevention: No vaccine available. People who have ever engaged in risky behavior – even if they have no symptoms – should be tested so that appropriate treatment can be started, if needed.