CROI2015: HCV transmission risk factors in HIV-infected MSM

post_croi2015Sexual transmission of hepatitis (HCV) is a very important yet poorly understood problem for both providers and patients. Although we have seen a rise in HCV infections in HIV-infected MSM since the early 2000s, there have not been many case-control or cohort studies specifically looking at risk factors and potential modes of transmission in HIV-infected MSM. To that end, Joost Vanhommerig and colleagues from the Netherlands conducted the MOSAIC study, the largest case-control study focusing on transmission of HCV in HIV-infected MSM. Results were presented on a poster at CROI 2015.

Beginning in 2009, HIV-infected MSM with acute HCV across 5 medical centers were given a written questionnaire covering a variety of demographic and risk factors including, but not limited to drug use, sexual risk behavior and other blood-borne risk factors for HCV. To date, there have been 213 MSM included, 82 with and 131 without HCV infection. Performing statistical analysis and comparing the HIV-infected MSM to the HIV-uninfected men as controls, the authors found the following risk factors associated with HCV transmission in HIV-infected MSM:

Sexual Practices Associated with HCV Transmission

Condomless Receptive Anal Sex
Ulcerative Sexually Transmitted Infections
Unprotected (no gloves) Fisting
Shared Sex Toys


Non-Sexual Factors Associated with HCV Transmission

Sharing of Straws for Snorting Drugs
Lower CD4 Cell Counts

In past reviews of sexual transmission of HCV, there are often questions about the role of injection drug use as a potential source of infection in HIV-infected MSM. Only 12 men in this study reported injection histories, and this was not associated with increased risk in this study. Also differing from past resuts, the study authors did not find a relationship with number of sex partners group sex participation or rectal bleeding. These are still worth considering as potential risk factors going forward. Additionally the authors call for further research on the role of CD4 count as a potential driver for HCV infection.

The authors conclude that sexual transmission and non-injection drug use are risk factors for HCV infections. This further supports the recommendations that sexually active MSM and those who do not use injection drugs should be routinely screened for HCV as a component of their sexual health and wellness.