How is hepatitis infection spread?

Hepatitis C virus, until recently, was known as non-A, non-B hepatitis because it could not be traced to A, B, or D viruses. In the late 1980s, genetic sequences of the virus were isolated and cloned, and a test for identifying an antibody to the virus was developed. The virus was designated hepatitis C. Transfused blood is one source of the transmission of this disease. Most hepatitis cases that occur as a result of blood transfusions are hepatitis C Hepatitis C also may be spread through intimate contact with an infected person.

Hepatitis D virus cannot initiate an infection by itself. A person must have acquired hepatitis B before becoming infected with hepatitis D. These viruses together usually produce a disease more severe than that caused by the hepatitis B virus alone. Hepatitis D virus is spread in the same ways as the hepatitis B virus. In the United States, infections with hepatitis D occur primarily among those who must receive blood products frequently, such as dialysis patients, hemophiliacs, or among those who inject illicit drugs.

Hepatitis E virus is acquired when water or food contaminated with human feces is ingested.