Introduction In Ireland, HIV infection predominantly occurs among men who have sex with men (MSM). Combination prevention approaches, including pre-exposure prophylaxis (PrEP), are recommended to reduce the risk of acquiring HIV. We used the 2015 MSM Internet Survey Ireland (MISI), a large-scale community survey among adult MSM in Ireland, to estimate the proportion of MISI respondents eligible for PrEP.

Methods We applied PrEP eligibility criteria from France to MISI variables. Where exact criteria could not be applied, the most similar form was used. French PrEP eligibility criteria include HIV negative MSM or transgender adults who had at least one of the following: condomless anal sex (CAI) with ≥2 different partners in the past six months; episodes of STIs in the past 12 months; used multiple post-exposure prophylaxis (PEP) treatment(s) or used drugs during sex.

Results MISI included 3,045 MSM aged 18–64 years; 2,870(94%) were HIV negative or never HIV tested. In the past 12 months, 370(12%) reported CAI with ≥2 non-steady partners; 243(8%) reported an STI diagnosis and 181(6%) used drugs associated with chemsex. Four percent (n=119) were treated with PEP. Overall, 23% [95%CI(22–25)] of MISI respondents are eligible for PrEP.

Discussion An estimated one in four MISI respondents met French PrEP eligibility criteria. Applying this estimate to the MSM population in Ireland, taking study limitations, those engaged in services and assumed PrEP uptake into account, would enable calculation of the number of MSM eligible for PrEP. This estimate will be useful for informing PrEP policy in Ireland.