Sexual Behaviour, HIV Prevention and Testing Among Transgender and Non-binary People in a Cross-Sectional Behavioural Surveillance Survey in Aotearoa New Zealand.

Trans and non-binary (TNB) people who have sex with gay, bisexual and other men who have sex with men (GBM) are rarely included in HIV behavioural surveillance. Improved data on risk and protective behaviours among TNB people could help identify unmet needs. We analysed data from the Sex and Prevention of Transmission Study, a cross-sectional HIV behavioural surveillance programme in Aotearoa New Zealand that extended eligibility to TNB participants for the first time in 2022. We categorised TNB participants who reported sex with GBM < 5 years into four groups: trans women (TW), trans men (TM), non-binary people assigned male at birth (AMAB), non-binary people assigned female at birth (AFAB). TNB participants were younger, more socioeconomically disadvantaged, and reported more long‑term disability than cis GBM. Compared to cis GBM, TM and non-binary AFAB participants reported fewer male partners and more sex with women and non‑binary partners, whereas TW and non-binary AMAB participants' partnering more closely resembled cis GBM. HIV testing < 12 months was lower across all TNB groups, and PrEP < 6 months was lower among TM and non-binary AFAB participants. Sexually transmitted infection screening and diagnosis < 12 months appeared similar across all participants; few TNB participants reported living with HIV. TNB participants reported higher levels of negative healthcare experiences and injecting drug use, but not methamphetamine use. Each TNB subpopulation had a unique behavioural profile that differed from both other TNB participants and cis GBM. Lower uptake of HIV testing and PrEP could reflect less risk exposure, service barriers, or both.