Drug Use and Transmission of Hepatitis C

Drug use and transmission of Hepatits C occurs with contaminated needles, which is the most common route of infection with Hepatitis C.

Injection drug use is responsible for at least 60 percent of Hepatitis C infection in the United States. The risk of sexual transmission of Hepatitis C (HCV) is much lower than the risk associated with contaminated needles, but still present. Sexual transmission is estimated to account for less than 20 percent of HCV transmission.

The highest rates of sexual transmission are associated with multiple sex partners, and the increased risk may be associated with traumatic sex that results in blood exposure.

Long-term monogamous sexual partners of persons infected with HCV have very low rates of becoming infected (0 to 4 percent). Prior to the discovery of the virus and the development of a screening test for blood, many people were infected through contaminated blood transfusions. Since 1992, infection from blood transfusions is rare in the United States.

The average rate of transmission from an infected pregnant mother to her infant is 5 to 6 percent (range 0 to 25 percent). This risk increases if the mother is infected with both HCV and HIV, with reported transmission rates of 5 to 36 percent.  Other potential risks for transmission of Hepatitis C and drug use includes sharing contaminated straws during intranasal use of cocaine, and sharing items such as razors and toothbrushes, which may be contaminated with infected blood.

Data on exposure risks from tattooing or piercing in the United States are sparse.