Dual cross-sectional and longitudinal perspective on the continuum of HIV care to disentangle natural epidemic evolution from real progress, Belgium 2014-2022.

Introduction: This study provides a comprehensive overview of HIV care by combining cross-sectional and longitudinal continuum of care (CoC) analyses.

Methods: Using national surveillance data 2014-2022, a five-stage cross-sectional CoC was calculated among people living with HIV (incl. undiagnosed): diagnosed, linked to care, retained in care, on antiretroviral therapy (ART) and virally suppressed. For the longitudinal CoC, cumulative incidences (CI) were calculated for each transition.

Results: The study included 26 191 people living with HIV. By the end of 2022, an estimated 18 302 persons were living with HIV in Belgium. Of these, 92.1% were diagnosed, 90.9% linked to care, 89.2% retained in care, 87.9% on ART and 85.6% virally suppressed. One-year post-infection diagnosis rates were 38% (2014-2016), 33% (2017-2019) and 31% (2020-2022), with differences disappearing after correction for immigration timing. Time from diagnosis to care entry remained stable at 82% within 3 months. Time to ART initiation and to viral load suppression reduced substantially, with 3-month CIs rising from 69% and 71%, respectively (2014-2016), to 91% and 77% (2020-2022). Transitions between all stages of care were the fastest among Belgian men who have sex with men. People who inject drugs had the lowest CI for care entry and viral suppression. Cumulative incidences of ART initiation increased substantially for all key populations, exceeding 90% within 3 months in 2020-2022, except for non-Belgian heterosexuals (87%).

Conclusion: A steady improvement in the CoC places Belgium close to the joint united nations programme on HIV/AIDS 95-95-95 targets, although populations like people who inject drugs and migrants still face significant barriers to care. Timely diagnosis by supporting existing and innovative testing strategies should be prioritized.