Did the COVID-19 pandemic shift the landscape of late HIV diagnosis?

Background: The COVID-19 pandemic profoundly disrupted healthcare services. This study assessed the impact of the pandemic on the incidence, characteristics, and outcomes of late HIV diagnosis (LD) in Italy. Methods: All people with HIV (PWH) enrolled in ICONA during 2016-2019 (pre-pandemic) and 2021-2024 (post-pandemic), and diagnosed with HIV within 3 months before enrolment, were included. LD was defined as CD4 <350 cells/mm³ or an AIDS-defining event (ADE) within three months of HIV diagnosis; AIDS presentation (AIDS-P) was considered an ADE at diagnosis. Annual incidence, socio-demographic determinants, and survival outcomes were compared between periods using Poisson regression, Cox proportional hazards models, and Fine-Gray competing risk models. Results: Among 5,724 newly diagnosed PWH, 56% were enrolled in pre-pandemic and 44% post-pandemic. Overall, 58% presented late and 13% as AIDS-P, with proportions stable across periods. Risk factors for LD - female sex, older age, foreign nationality, heterosexual transmission, lower education, and unemployment - remained consistent, with no significant interaction by time (p = 0.39). During follow-up, 151 deaths occurred. LD and especially AIDS-P were associated with substantially increased all-cause mortality compared with non-LD, particularly within the first-year post-diagnosis. Adjusted hazard ratios were 2.96 for LD and 6.51 for AIDS-P pre-pandemic, and 8.64 and 17.99 post-pandemic. No excess risk was observed for non-AIDS-related mortality. Conclusions: The prevalence and determinants of LD and AIDS-P in Italy remained stable before and after the COVID-19 pandemic. However, late presentation continues to carry a heavy mortality burden, underscoring the urgent need to strengthen early testing and prompt linkage to care.