Injection and Sexual Behavior Profiles among People Who Inject Drugs in Miami, Florida

The dynamics of injection drug use and higher-risk sexual practices compound the risk of HIV and HCV acquisition. Published literature on people who inject drugs (PWID) has examined risk of infection assuming homogeneity of cohort behavior. Categorizing subgroups by injection and sexual risk can inform a more equitable approach to how syringe services programs (SSPs) adapt harm reduction resources and implementation of evidence-based interventions. We explored injection and sexual risk profiles among PWID to determine significant predictors of class membership.

Data were collected from 1,272 participants at an SSP in Miami-Dade County. Latent Class Analysis (LCA) examined how 10 injection/sexual behavior indicators cluster together to create profiles. Model fit statistics and multivariable multinomial latent class regression identified the optimal class structure and significant predictors of class membership. We assessed SSP visits, naloxone access, HIV/HCV testing and prevalence, and incidence of self-reported wounds.

Three distinct profiles of injection/sexual risk were determined: Low Injection/High Sexual (LIHS) (9.4%); High Injection/Moderate Sexual (HIMS) (18.9%); and Low Injection/Low Sexual (LILS) (71.7%). Participants reporting gay/bisexual orientation and methamphetamine injection more likely belonged to the LIHS class. LIHS class members had higher prevalence of HIV, while those of HIMS reported increased hepatitis C prevalence. Compared to members of LILS, those of HIMS more likely experienced unstable housing, gay/bisexual orientation, heroin or speedball injection, and identifying as women. HIMS cohort members had more SSP visits, naloxone accessed, and higher wound incidence than those of LILS.

Understanding PWID subgroups amplifies the importance of implementing evidencebased interventions such as PrEP for those engaging in highest risk behavior, with focused interventions of antiretroviral management and access to condoms for members of the LIHS class and HCV screening with wound care for those belonging to HIMS.