Incorporating acute HIV infection screening, same-day diagnosis and antiretroviral treatment into routine services for key populations at sexual health clinics in Indonesia: a baseline analysis of the INTERACT prospective study

Introduction: Indonesia has an escalated HIV epidemic concentrated among key populations. To strengthen the care cascade, we implemented a care pathway for the screening of individuals for acute HIV infection (AHI), to achieve prompt diagnosis and antiretroviral treatment (ART) initiation, at three non-governmental sexual health clinics in Jakarta and Bali. We assessed the AHI testing uptake, yield and prevalence, and the care cascade. Methods: This is a cross-sectional baseline analysis of individuals (≥16 years) who presented for HIV testing and were consecutively enrolled (May 2023−November 2024). We used an AHI risk-score self-assessment and test algorithm comprising a fourth-generation antibody/p24 antigen rapid diagnostic test (4gRDT; Abbott Determine HIV Early Detect) and, if negative/discordant, followed by HIV-PCR (Cepheid Xpert) (either individual or pooled-sample testing). AHI was pragmatically defined as having negative/discordant RDT results with positive HIV-PCR (ISRCTN41396071). Results: Three thousand seven hundred and ninety-seven (44.0%) of 8665 individuals were screened for study eligibility, and 3689 (97.2%) were enrolled. Median age was 28 years, and 78.2% were male. Men who have sex with men (MSM) accounted for 53.3%, clients of sex workers 19.2%, persons having a sex partner living with HIV 8.9% and sex workers 4.1%. We diagnosed 229 (6.3%; 229/3662) persons with RDT-positive (chronic) HIV, and we additionally identified 13 persons with AHI—that is a diagnostic yield of 5.6% (95% CI 3.1−9.5; 13/229) overall, and 6.1% (95% CI 3.2−10.3; 12/198) among MSM. AHI prevalence was 0.38% (95% CI 0.20−0.65; 13/3429) overall, and 0.72% (95% CI 0.37−1.2; 12/1677) among MSM. The number of persons needed to test to identify one person with AHI was 264 (3429/13) overall and 140 (1677/12) among MSM. The 4gRDT's performance to detect AHI was poor (2/13). Most participants received their HIV-PCR results on the same day (84.8%, 2907/3429) or within 24 hours (92.8%, 3182/3429). Of the 242 newly HIV-diagnosed individuals, 236 (97.5%) started ART, of whom 158 (67.0%) on the same day and 215 (91.1%) within 1 week. Conclusions: We successfully implemented prompt AHI diagnosis and treatment, and identified a high AHI prevalence among Indonesian MSM. Prioritizing access to AHI testing can create opportunities for enhanced interventions to curb the HIV epidemic among key populations.