Hep, an abbreviation for Hepatitis. Usually used along with the letter designating the type of hepatitis, such as Hep-B and Hep-C. Hepatitis is a dangerous virus which is easier to catch than AIDS and can be fatal (it tends to affect the liver). For every 1 person infected with AIDS, there are 4 infected with Hepatitis C. There is no vaccine, and no completely effective treatment. In the U.S., 8,000 to 10,000 people die from Hep-C each year.