Emerging patterns in HIV integrase resistance.

We assessed integrase resistance in 837 treatment-experienced people with HIV (PWH) with virological failure (2022-2024) in Portugal. Major resistance mutations were found in 5.5%, with N155H and R263K being the most common. Resistance was more frequent in non-B subtypes and often co-occurred with resistance to other antiretroviral classes. Though prevalence remains low, the findings highlight the need for continued surveillance to inform treatment decisions, especially as integrase inhibitors like dolutegravir, bictegravir and cabotegravir become more widely used.