People living with HIV and proportion diagnosed in Aotearoa New Zealand: first published national estimates from two modelling approaches

Abstract Background Aotearoa New Zealand (NZ) is a country of low HIV incidence and prevalence where men who have sex with men (MSM) are most affected, and indigenous Māori inequitably affected by late diagnosis. NZ aims for 95% of people living with HIV (PLWH) diagnosed. We estimated PLWH and proportion (%) diagnosed in 2024 using two mathematical models; the first estimate by local researchers. Methods We used the European Centre for Disease Prevention and Control (ECDC) HIV Modelling tool and Spectrum Case Surveillance and Vital Registration model with NZ surveillance data to estimate total PLWH, proportion diagnosed, and incident acquisitions in 2024. We used both models to estimate PLWH and diagnosed proportion by gender, and the ECDC model to estimate these indicators for MSM and people with heterosexual acquisition, and for Māori. Results Overall PLWH and diagnosed proportion estimates in 2024 were similar between models: 3991 (95% CI 3849-4116) PLWH with 95% (95% CI 93-97%) diagnosed from ECDC, and 3939 (95% uncertainty bounds 3286-4508) PLWH with 96% (95% uncertainty bounds 94-98%) diagnosed from Spectrum. Estimates by gender were similar between models. The proportion of people diagnosed increased in all populations over time, but the ECDC model estimated non-significantly lower proportions of diagnosed MSM (93%, 95% CI 85-96%) compared to heterosexual people (95%, 95% CI 92-98%), and Māori (86%, 95% CI 70-96%) compared to non-Māori non-Pacific people (96%, 95% CI 94-96%). The ECDC model found a greater incidence decline from 2010, to 14 new acquisitions (95% CI 11-17, 88% decline) in 2024. Conclusions Findings suggest 95% of PLWH overall in NZ were diagnosed in 2024, meeting the UNAIDS target. Incidence had declined steadily since 2010. While our findings highlight successes of community prevention and testing initiatives, further strategies are needed for continued and equitable progress to eliminating HIV transmission.