Persons at Risk
Transmission of hepatitis C virus (HCV) through heterosexual contact appears to be uncommon, with early studies showing transmission among long-term monogamous heterosexual partners occurring in less than 1% of couples per year.[1,2,3,4] In a more recent large cross-sectional study of persons with HCV and their partners, investigators estimated a maximum incidence rate of 0.07% per year among monogamous heterosexual couples, which corresponded to approximately one transmission per 190,000 sexual contacts.[5] This risk increases slightly among persons who have multiple sex partners.[6] Multiple reports have identified clusters of acute hepatitis C infection among men who have sex with men (MSM), primarily MSM who are also coinfected with HIV.[7,8,9,10,11] When comparing the risk of HCV acquisition among MSM with or without HIV, the risk is significantly higher among MSM who have HIV.[12] Recent cohort studies have also shown a high rate of HCV reinfection among MSM living with HIV, with risk of reinfection associated with ongoing sexual practices and/or injection drug use.[13,14,15,16]
Factors Associated with Increased Risk of Sexual Transmission
For heterosexuals, having multiple sex partners has been associated with an increased risk of HCV acquisition.[6] Investigators have identified multiple risk factors associated with sexual transmission of HCV among MSM:[12,16]
- Coinfection with HIV
- Unprotected anal intercourse, especially as the receptive partner
- Inconsistent condom use
- Use of recreational drugs, particularly use of drugs during sex
- Recent or concurrent sexually transmitted infections, especially ulcerative sexually transmitted diseases (lymphogranuloma venereum proctitis, syphilis)
- Multiple casual or anonymous sex partners
- Group sex
- Certain sex practices that result in rectal bleeding or damage to the rectal mucosa, including fisting and use of shared sex toys.
Prevention
The Centers for Disease Control and Prevention (CDC) recommends that persons with HCV who have one long-term steady sex partner do not need to alter their sex practices.[17] Long-term partners should be offered the option of receiving HCV counseling and undergoing HCV testing. For HCV-serodifferent couples attempting to maximize reduction of the risk of HCV transmission, using latex condoms and avoiding sex practices that potentially result in bleeding should presumably further reduce the risk of sexual HCV transmission. Individuals with known hepatitis C should be counseled to disclose their HCV status with their sex partners. In addition, persons with HCV who have multiple sex partners should consistently use condoms during sexual activity to reduce their risk of transmitting HCV to their partners and to reduce the risk of transmission or acquisition of other sexually transmitted diseases, including HIV and hepatitis B virus. Given the significant potential risk of sexual transmission of HCV among MSM, particularly MSM with HIV infection, it is important for medical providers and persons with HCV to discuss sex and drug use practices known to increase the risk of transmitting HCV. Individuals should also be counseled that reinfection with hepatitis C can occur and be offered counseling on safer sex and drug use practices that reduce the risk for reinfection. For persons with HIV and HCV coinfection who are taking HIV antiretroviral therapy and have consistently undetectable HIV RNA levels, their risk of HIV transmission is extremely low, but they need to be reminded that HIV antiretroviral therapy will not impact their risk of transmitting HCV to others.