Incidence of Hepatitis-C Among HIV Infected Men Who Have Sex With Men (MSM) Attending a Sexual Health Service: a Cohort Study, Deepa G. Gamage et. al., BMC Infectious Diseases (2011)

This Australian study looked at the incidence of hepatitis C infection (HCV) among HIV-positive men who have sex with men (MSM). In doing so, the study hoped to find evidence of whether or not HCV can only be transferred via drug injection or if it is possible for it to spread via sexual contact as well. Ultimately the study found that a portion of HIV-positive MSM contracted HCV even though they did not inject drugs—suggesting to the authors that it is possible for HCV to be transferred sexually among seropositive MSM. The authors do not thoroughly delve into the extent to which these transmissions may be linked to blood during sexual contact.

Co-infection of HIV and HCV is associated with heightened risk of HCV-related liver disease and increases the risk for cirrhosis and liver cancer. Unfortunately, there is still much that is unknown about how HCV is transferred. Many believe that it is only possible to transfer through blood exposure, such as injecting drugs. Other studies suggest that it is possible for HCV to be transferred between MSM through sexual means, though the data remains conflicted, and the blood exposure in sexual contact remains largely undiscussed. By having a larger group to analyze, this study hoped to come up with clearer data on HCV transferability in HIV-positive MSM.

Drawing its results from a pool of 1,065 MSM who attended a health clinic, 869 (82%) of the participants were tested for HCV at any time after HIV diagnosis. Given that some had HCV before their HIV diagnosis, however, 620 MSM who did not have HCV prior to their HIV diagnosis were monitored during the study. Of these individuals, 40 incidents of HCV were detected. Of these, 16 were from injecting drug users (IDU); 24 HCV diagnoses, however, were in non-IDU MSM. The study found that MSM who do not inject drugs have a low, but still significant HCV rate of about 0.5% per year.