Are we on the precipice of a new epidemic? Risk for hepatitis C among HIV-negative men-, trans women-, and trans men- who have sex with men in the United States.

Emerging data from Europe have documented increases in diagnoses of acute hepatitis C virus (HCV) infection among HIV-negative men who have sex with men. We investigated risk factors for HCV and their correlates in the Together 5000 study, a U.S. national cohort study of HIV-negative men (n = 6089), transgender women (n = 40), and transgender men (n = 42) who have sex with men. We used bivariate and multivariable analyses to determine demographic and behavioral factors associated with high risk for acute HCV infection (using the HCV-MOSAIC risk indicator with a score ≥ 2.0). Mean HCV risk score was 1.38 (SD = 1.09) and 27.3% of participants had HCV risk scores ≥ 2.0. In multivariable modeling, being cisgender male (vs. not) was associated with having a lower HCV-MOSAIC risk score. Meanwhile, being white, having been incarcerated, prior use of HIV pre- or post-exposure prophylaxis, having ever been tested for HIV, and recent methamphetamine use were associated with high risk for HCV. More than one-in-four participants exceeded the threshold score for HCV risk. Those with high HCV-MOSAIC risk scores were more likely to have been in settings where they could be tested for acute HCV (i.e., HIV testing, PrEP care, PEP care, incarceration), suggesting opportunities to engage them in HCV screening, prevention, and treatment.