Transmission rate by half among HIV-positive men MSM

New hepatitis C (HCV) transmissions fell by about 50% in HIV-positive men who have sex with men and chronic HCV infections decreased by over 92% after an HCV treatment as prevention intervention was started in a Switzerland, according to a study presented at CROI.

Results from the HCVRee study, which were presented by Dominique Braun, M.D., demonstrated an effective model for HCV treatment as prevention. The study followed the same cohort (the Swiss HIV Cohort Study, or SHCS) that brought upon the original 2008 Swiss Statement, which declared that an HIV-positive person on effective treatment and who has undetectable viral load cannot transmit HIV through sex—what’s known today as undetectable = untransmittable (U=U).

In Switzerland, new HCV infections have increased over 18 times in HIV-positive men who have sex with men (MSM) since 2002, the researchers noted.

The HCVRee study consisted of HCV screening, HCV treatment, and HCV re-screening.

The study screened 87% of MSM in the Swiss HIV Cohort Study, an ongoing study that follows individuals living with HIV in Switzerland. Participants are screened yearly using an HCV antibody test. The HCVRee study used an HCV RNA test, which detects HCV sooner than an antibody test. 

Out of the 3,722 HIV-positive MSM who were screened, 177 were found to be HCV positive—translating into a 4.8% HCV prevalence pre-intervention. The majority of these individuals, 166 MSM (94%), had either genotype 1 or 4 HCV and the remaining 11 individuals (6%) had either genotype 2 or 3 HCV.

The researchers found that 17% of these cases were new HCV infections (meaning the individuals were HCV-negative before phase A) and 83% were chronic HCV infections (meaning these individuals had already received a positive HCV test before phase A).

In phase B, the researchers offered direct-acting antiviral (DAA) treatment to the 177 individuals who had tested positive for HCV. About 91% of the individuals accepted treatment. Of these 161 MSM who accepted treatment, 122 received Zepatier (grazoprevir/elbasvir). The remaining 39 had a contraindication to Zepatier and received standard-of-care DAA treatment according to European and U.S. treatment guidelines. A behavioral intervention was also offered.

Among those who received treatment, 99.5% achieved SVR12, which is a sustained virologic response for 12 weeks, or what’s commonly considered HCV cure. For those receiving Zepatier, 99% achieved cure, while 100% of those receiving standard-of-care regimens were cured.

During phase C, the 3,722 HIV-positive MSM who were enrolled in the study were rescreened by HCV RNA test. This time, only 28 individuals were found to be HCV-positive—translating into a 0.8% HCV prevalence. HCV prevalence dropped from 4.8% pre-intervention to 0.8% post-intervention.

Out of the 28 HIV-positive MSM who tested positive for HCV, 16 (57%) were new HCV infections and 12 (43%) were chronic HCV infections, which were not treated during phase A of the study. Out of these 28 individuals, 22 were treated and 100% of them achieved HCV cure.

Overall, 206 HIV-positive MSM in this study were diagnosed with HCV. Of these, 132 were treated with Zepatier, 51 were treated with standard-of-care treatment regimens, four experienced self-clearance of HCV, 11 refused treatment, six did not receive treatment because of their physician’s decision, one was lost to follow-up, and one died.

Overall, after the intervention, new HCV infections decreased by 49%, from 31 cases to 16 cases. At the same time, chronic infections decreased by 92.5%, from 147 cases to 12 cases. There were about eight months between the end of phase A and the beginning of phase C.

The researchers will will continue to screen and assess HCV incidence over long-term follow-up and evaluate the impact of their behavioral intervention program on sexual risk behavior.

Warren Tong is a freelance health and science journalist, with an extensive background writing about HIV and hepatitis C. Follow Warren on Twitter: @warrentong.