Varied Knowledge of HIV Transmission and Prevention Among Gay, Bisexual, and Heterosexual Men Who Have Sex with Men in Australia: Results of a National Online Survey.

We assessed knowledge about HIV transmission and prevention among men who have sex with men (MSM) to identify education needs. A national online survey was conducted across Australia in July-August 2024, including nine HIV knowledge items. We assessed how HIV knowledge varied by sexual identity (using ANOVA), and characteristics independently associated with HIV knowledge using multivariable linear regression. Of 2,688 respondents, 1,241 were gay men (46.2%), 976 were bisexual/pansexual (36.3%), 84 queer (3.1%), 199 straight/heterosexual (7.4%), and 188 identified another way (7.0%). There was high common knowledge of condoms' effectiveness (range 92.5-95.1%), relatively high awareness of HIV post-exposure (66.3-91.4%) and pre-exposure prophylaxis (PrEP, 56.3-81.4%), but greater uncertainty that HIV cannot be transmitted via saliva (50.8-70.6%) and the low risk of oral sex (46.8-64.2%). There was low awareness that rapid HIV tests were available from pharmacies (34.8-39.2%). Gay men had the highest HIV knowledge scores (mean 6.9), followed by queer (6.4), bisexual/pansexual (5.7), other identified (5.6) and heterosexual participants (5.3). HIV knowledge was greater among participants who were university educated, more open about sex with men and socially engaged with LGBTQ people, PrEP users, and people living with HIV. Knowledge was lower among bisexual/pansexual, heterosexual and other identified MSM, and untested/unknown status participants. We recommend targeted HIV education efforts be developed for non-gay-identified MSM that address common misconceptions about HIV transmission, contemporary HIV prevention and testing options, and reassure MSM that oral sex is safe and HIV is not transmitted via saliva.