The risk of sexually transmitting hepatitis C depends on the type of sex you are having. Because hepatitis C is thought to be transmitted via blood-to-blood contact, only sexual activities that increase the potential for exposure to blood are considered risky.
The risk of sexual transmission of hepatitis C is widely considered to be extremely low in heterosexual relationships. A study looked at 895 monogamous heterosexual people whose partner was chronically infected with HCV. Over a ten year period, none of them was infected by their partner. However, these couples denied having unprotected anal sex or vaginal sex during menstruation.
Sexual behaviours that increase the potential for exposure to blood heighten the possibility of transmitting HCV: the risk to men who have sex with men (MSM) and other people who might have unprotected anal sex is higher than the general population. Other sexual behaviours which can increase the potential for exposure to blood are listed below.
Coinfection with HIV also increases the risk of sexual transmission independent of any particular sexual behaviours.
For people who inject drugs, it is important to know that sharing injecting equipment with a sexual partner presents a much higher risk of transmitting hepatitis C than having regular unprotected sex with them.
What sexual activities increase the risk of sexual transmission?
Sexual activities which increase the potential for exposure to blood heighten the risk of transmitting hepatitis C.
Sexual behaviour considered to be risky includes but is not limited to:
- Unprotected anal sex
- Sharing sex toys that have been used anally
- Unprotected fisting
- Sex involving more than two people
- Chemsex (using drugs during sex: commonly crystal meth, GHB/GBL) Sharing a straw to snort drugs while engaging in sexual activities increases the risk of transmitting HCV
- Vaginal sex during menstruation
- Having sex when infected with an STI that could lead to blood-to-blood contact
- Any sexual activities which have the potential for blood-to-blood contact inherently increase the risk of transmitting hepatitis C. This includes rough vaginal sex that could cause bleeding from the penis or vagina. There is also a risk of blood leaking from any lesions on the penis.
- Engaging in two or more types of risky sexual behaviour significantly increases the risk of transmitting hepatitis C.
Other activities such as rimming and anal or vaginal fingering are not seen to increase the risk of transmitting hepatitis C. Oral sex is also considered to carry an extremely low risk of transmitting the virus.
HCV prevalence is much higher among people who are HIV-positive than those who are not. Research indicates that coinfection with HIV increases the viral load of HCV, therefore increasing the risk of you transmitting the virus to someone else when engaging in risky sexual activities.
However, it is not clear whether being infected with HIV makes you more likely to become infected with hepatitis C from someone else when engaging in risky sexual activities. Nevertheless, numerous studies prove that the prevalence of HCV is higher among the HIV-positive population (particularly among HIV-infected MSM) than people who are do not have HIV.
The apparent connection between HIV infection and risk of contracting HCV has also been linked to a low CD4 cell count. CD4 cells are a type of white blood cell that fights infection. Although it is not well researched, studies have reported higher HCV incidence among HIV-infected people who have lower CD4 cell counts.