Hepatitis C Prevalence, Correlates, and Social Networks among Cisgender Women who Participate in Sex Work in Seattle, WA

Background: Globally, injection drug use (IDU) is common among cisgender women who participate in sex work (CWSW), placing them at heightened risk of HCV acquisition and transmission. However, the epidemiology of HCV among CWSW in the United States is not well understood. In this study among CWSW in Seattle, we sought to estimate HCV prevalence, identify correlates of HCV seropositivity, and characterize recruitment networks by serostatus and IDU history. Methods: This study is a secondary analysis of data from the 2016 National HIV Behavioral Surveillance (NHBS) survey in Seattle, WA, a cross-sectional survey which used respondent-driven sampling (RDS) methods to recruit women who reported exchanging sex for money or drugs. We estimated HCV seropositivity among CWSW and used log binomial regression to estimate prevalence ratios (PRs) for correlates of HCV seropositivity at an α-level of 0.05. Using RDS recruitment chain data, we computed homophily indices to estimate the extent to which participants were likely to recruit another participant with the same HCV serostatus and history of IDU, beyond random chance. Results: We estimated HCV seropositivity prevalence to be 60.5% (95% CI: 54.6, 66.1) among the sample of largely (61%) street-based CWSW in Seattle. In bivariate models, CWSW who were HCV seropositive were more likely than those who were HCV seronegative to report ever injecting drugs (PR: 7.51 [3.33, 16.96]) and less likely to report using only drugs other than opioids or methamphetamine by non-injection routes in the past 12 months (PR: 0.53 [0.31, 0.91]). In the multivariate model, the association between HCV seropositivity and IDU remained (PRadj: 8.03 [3.45, 18.66]) and there was no association with non-injection drugs. The RDS-based homophily scores for HCV-seropositivity (0.07) and ever injecting drugs (0.02) suggested that participants did not tend to recruit others with the same characteristics much beyond chance. Conclusion: Among CWSW in Seattle, HCV prevalence is high and is strongly associated with a history of IDU. The high burden of HCV among CWSW motivates the provision of health services developed with a harm reduction lens for this population as well as the opportunity to target this population with treatment by direct acting antiviral (DAA) drugs. The analysis of RDS recruitment chains revealed little evidence of preferential recruitment among CWSW who were HCV-seropositive or reported a history of IDU, which suggests the potential futility of peer- or network-based referrals for HCV treatment.