A 32-year-old woman had sex with a man she met while on vacation 6 weeks ago. She was intoxicated at the time and does not know much about the person. She recalls having engaged in vaginal intercourse without a condom. She does not have any symptoms.
She previously received baseline lab testing per Centers for Disease Control and Prevention guidelines 2 years ago with a negative HIV test and negative hepatitis C test. She asks for testing for STIs. What would you recommend?
A. HIV, hepatitis C, gonorrhea, chlamydia, and human papillomavirus
B. HIV, hepatitis C, gonorrhea, chlamydia, and herpes simplex virus
C. HIV, hepatitis C, gonorrhea, and chlamydia
D. HIV, gonorrhea, and chlamydia
E. Gonorrhea and chlamydia
HIV risk estimate
The most practical answer is E, check for gonorrhea and chlamydia. Many protocols in place for evaluating people for STIs will test for hepatitis C as well as HIV with single exposures. In this column, we will look at the lack of evidence of heterosexual sexual transmission of hepatitis C.
In regards to HIV risk, the estimated risk of transmission male to female from an HIV-infected individual is 0.08% per sexual encounter.1 The prevalence in the United States – where HIV occurs in about 0.5% of the adult population – was used to estimate the risk of a person with unknown HIV status acquiring HIV. The calculated risk from one sexual encounter would be 0.0004 (1 in 250,000).
Studies of hepatitis C transmission
Tahan and colleagues did a prospective study of 600 heterosexual couples where one partner had hepatitis C and the other didn’t. Over a mean of 3 years of follow-up, none of the seronegative spouses developed hepatitis C.2
Terrault and colleagues completed a cross-sectional study of hepatitis C virus (HCV)–positive individuals and their monogamous heterosexual partners to evaluate risk of sexual transmission of HCV.3 Based on 8,377 person-years of follow-up, the estimated maximum transmission rate was 0.07%/year, which was about 1/190,000 sexual contacts. No specific sexual practices were associated with transmission. The authors of this study concurred with CDC recommendations that persons with HCV infection in long-term monogamous relationships need not change their sexual practices.4
Vandelli and colleagues followed 776 heterosexual partners of HCV-infected individuals over 10 years.5 None of the couples reported condom use. Over the follow up period, three HCV infections occurred, but based on discordance of the typing of viral isolates, sexual transmission was excluded.
Jin and colleagues completed a systematic review of studies looking at possible sexual transmission of HCV in gay and bisexual men.6 HIV-positive men had a HCV incidence of 6.4 per 1,000 person-years, compared with 0.4 per 1000 person-years in HIV-negative men. The authors discussed several possible causes for increased transmission risk in HIV-infected individuals including coexisting STIs and higher HCV viral load in semen of HIV-infected individuals, as well as lower immunity.
In hepatitis C–discordant heterosexual couples, hepatitis C does not appear to be sexually transmitted.
The risk of sexual transmission of hepatitis C to non–HIV-infected individuals appears to be exceedingly low.
Many thanks to Hunter Handsfield, MD, for suggesting this topic and sharing supporting articles.
Dr. Paauw is professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. He is a member of the editorial advisory board of Internal Medicine News. Dr. Paauw has no conflicts to disclose. Contact him at email@example.com.
1. Boily MC et al. Lancet Infect Dis. 2009 Feb;9(2):118-29.
2. Tahan V et al. Am J Gastroenterol. 2005;100:821-4.
3. Terrault NA et al. Hepatology. 2013;57:881-9
4. Centers for Disease Control and Prevention. MMWR Recomm Rep. 1998;47:1-38.
5. Vandelli C et al. Am J Gastroenterol. 2004;99:855-9.
6. Jin F et al. Sexual Health.2017;14:28-41.