Social and territorial inequalities in late HIV diagnosis in Greater Paris, France: The ANRS-MIE COINCIDE Study

Background: Late HIV diagnosis (LD) remains a major challenge in controlling the HIV epidemic, contributing to higher morbidity, mortality, and ongoing transmission. We aimed to estimate its prevalence and to identify associated socio-territorial inequalities in Greater Paris. Methods: This observational study included PLWH diagnosed during 2014-2021 and treated in all HIV hospital centers across Greater Paris. Seven transmission groups were defined according to birth region, gender, and transmission mode. Neighborhood deprivation was assessed using the French Deprivation Index (FDEP) based on residence place. Factors associated with LD were identified using multilevel modeling. Findings: Among 8,346 PLHW, 58% were born abroad, 43% were MSM, and 16% lived in precarious housing (3% among French-born MSM (FMSM) vs. 26% and 30% among foreign-born heterosexual men (fHM) and women (fW)) Overall, 47% lived in the most deprived neighborhoods, reaching 64% among fHM and 62% among fW. Nearly half had LD (47%), ranging from 30% among FMSM, to 65%/57% among fHM/fW. In multivariate analysis, LD was associated with living in deprived neighborhoods (aOR=1.39, 95%CI [1.17-1.65]). After adjustment for transmission group, all groups showed higher LD risk than FMSM, and previous associations disappeared. Conclusion: Living in deprived areas was associated with higher LD risk, driven by the concentration of high-risk populations (fHM and fW) and reflecting the socio-spatial segregation of PLWH. These findings highlight the need for innovative, geography-based, screening strategies that go beyond traditional risk-group approaches. Moreover, the seven-category of the transmission group classification represents a valuable social indicator for studying health inequalities among PLWH.