The risk of sexual transmission of hepatitis C is considered very low. However, this risk increases for sexual activities where there is potential exposure to blood. This includes vaginal sex during menstruation or anal sex with the associated risk of bleeding. Sex toys used during these activities are also potential source of infection.
Oral sex in the absence of blood is considered to be a low risk activity. In addition, the presence of certain sexually transmitted infections may increase the risk. Unprotected sex, even once, with someone who is co-infected with HIV and HCV poses a significant risk. The risk of hepatitis C transmission is much higher in the presence of HIV. Read the results of a 10 year study into sexual transmission below:
Sexual Transmission Study - Hepatology 2012
The efficiency of hepatitis C virus (HCV) transmission by sexual activity remains controversial. We conducted a cross-sectional study of HCV-positive persons and their partners to estimate the risk for HCV infection among monogamous heterosexual couples.
500 anti-HCV-positive, HIV-negative index persons and their long-term heterosexual partners were studied. Couples were interviewed separately for lifetime risk factors for HCV infection, within-couple sexual practices and sharing of personal grooming items. Blood samples were tested for anti-HCV, HCV RNA, and HCV genotype and serotype. Sequencing and phylogenetic analysis determined the relatedness of virus isolates among genotype-concordant couples.
HCV-positive index persons were mostly Non-Hispanic Whites, with median age 49 years (range 26-79) and median 15 years (range 2-52) of sexual activity with their partners. Overall, HCV prevalence among partners was 4% (n=20), and 9 couples had concordant genotype/serotype. Viral isolates in 3 couples (0.6%) were highly related, consistent with transmission of virus within the couple. Based upon 8377 person-years of follow-up, the maximum incidence rate of HCV transmission by sex was 0.07% per year (95% CI: 0.01, 0.13) or ∼1 per 190,000 sexual contacts. No specific sexual practices were related to HCV-positivity among couples.
The results of this study provide quantifiable risk information for counseling long-term monogamous heterosexual couples in which one partner has chronic HCV infection. In addition to the extremely low estimated risk for HCV infection in sexual partners, the lack of association with specific sexual practices provides unambiguous and reassuring counseling messages. (HEPATOLOGY 2012.).
Copyright © 2012 American Association for the Study of Liver Diseases.
Sexual transmission - European study
No Evidence of Sexual Transmission of Hepatitis C among Monogamous Couples: Results of a 10-Year Prospective Study
The risk of sexual transmission of hepatitis C virus (HCV) infection was evaluated among 895 monogamous heterosexual partners of HCV chronically infected individuals in a long-term prospective study, which provided a follow-up period of 8,060 person-years. Seven hundred and seventy-six (86.7%) spouses were followed for 10 yr, corresponding to 7,760 person-years of observation.
One hundred and nineteen (13.3%) spouses (69 whose infected partners cleared the virus following treatment and 50 who ended their relationship or were lost at follow-up) contributed an additional 300 person-years.
All couples denied practicing anal intercourse or sex during menstruation, as well as condom use. The average weekly rate of sexual intercourse was 1.8.
Three HCV infections were observed during follow-up corresponding to an incidence rate of 0.37 per 1,000 person-years. However, the infecting HCV genotype in one spouse (2a) was different from that of the partner (1b), clearly excluding sexual transmission.
The remaining two couples had concordant genotypes, but sequence analysis of the NS5b region of the HCV genome, coupled with phylogenetic analysis showed that the corresponding partners carried different viral isolates, again excluding the possibility of intra-spousal transmission of HCV.
The authors conclude, Our data indicate that the risk of sexual transmission of HCV within heterosexual monogamous couples is extremely low or even null. No general recommendations for condom use seem required for individuals in monogamous partnerships with HCV-infected partners.
Carmen Vandelli and others. Lack of Evidence of Sexual Transmission of Hepatitis C among Monogamous Couples: Results of a 10-Year Prospective Follow-Up Study. American Journal of Gastroenterology 99(6): 855-859. May 2004.