Structural vulnerabilities and PrEP awareness among Boston heterosexuals and people who inject drugs at risk for HIV: findings from 2018 to 2019 cycles from the Boston, MA site of the NHBS

Little is known about biopsychosocial factors relating to pre-exposure prophylaxis (PrEP) awareness among people with either heterosexual or injection drug use HIV risk behaviors. Participants engaged in vaginal/anal sex with a person of the opposite sex (N = 515) or were people who injected drugs (PWID; N = 451) in the past 12 months from 2018-2019 in Boston, MA. We examined associations between PrEP awareness and: homelessness; perceived HIV-related stigma; country of birth; bacterial STDs, chlamydia, and/or gonorrhea in the past 12 months, lifetime hepatitis C virus (HCV) infection, sexual orientation, and poverty. More PWID (36.8%) were aware of PrEP than people with heterosexual HIV risk (28%; p = .001). Among people with heterosexual risk, homelessness (aOR = 1.99, p = .003), and among PWID: homelessness (aOR = 2.11, p = .032); bacterial STD (aOR = 2.96, p = .012); chlamydia (aOR = 6.14, p = .008); and HCV (aOR = 2.40, p < .001) were associated with increased likelihood of PrEP awareness. In the combined sample: homelessness (aOR = 2.25, p < .001); HCV (aOR = 2.18, p < .001); identifying as homosexual (aOR = 3.71, p = .036); and bisexual (aOR = 1.55, p = .016) were each associated with PrEP awareness. Although having an STD, HCV, identifying as homosexual or bisexual, and experiencing homelessness were associated with increased PrEP awareness, most participants were unaware of PrEP. Efforts to increase PrEP awareness could engage PWID and heterosexual HIV risk behavior.