Persistent HIV Transmission Misconceptions Among People Who Inject Drugs in Massachusetts, USA.

Despite the widespread success of combination antiretroviral therapy in reducing overall HIV morbidity and mortality, people who inject drugs (PWID) continue to experience elevated risk of infection and suboptimal care outcomes. Addressing knowledge gaps related to HIV acquisition and transmission is essential for reducing incident cases of HIV. We assessed HIV transmission misconceptions (e.g., HIV can be transmitted through sharing cigarettes, hugging an infected person) among HIV-negative PWIDs recruited through two syringe service programs in Massachusetts between 2020 and 2025. Participants completed 10 items adapted from the International AIDS Questionnaire, with responses categorized into three groups: 'many misconceptions' (0-7 questions answered correctly), 'few misconceptions' (8-9 correct), and 'no misconceptions' (10 correct). Of 185 participants, 79% held at least one misconception. The most common misconception was that HIV could be transmitted through mosquitoes (55% incorrect). The least prevalent misconceptions related to condom use, drug injection "works" (e.g., cookers, cottons), and hugging (≥ 90% answered correctly). We also observed misconceptions related to syringe sharing (13% incorrect) and mother-to-child transmission (17% incorrect; no difference between women and men). Sociodemographic characteristics did not differ significantly across misconception categories. Participants who reported a recent overdose represented 27% of the full sample but 45% of the 'no misconceptions' subgroup. Misconceptions present since the early era of the HIV epidemic remain prevalent among PWID in this region, despite access to robust harm reduction and HIV prevention services. Findings highlight the importance of dispelling long-standing myths, strengthening education about preventive perinatal transmission, and reinforcing knowledge of injection-specific transmission.