CROI 2025 Abstract eBook

Abstract eBook

Poster Abstracts

Republic of Congo (DRC), this disease has become a public health emergency, with 19,667 suspected cases and 575 deaths reported in 2024. Monkeypox virus (MPXV) represents a diagnostic challenge due to the diversity of clinical presentations. These symptoms often share similarities with infection caused by herpes simplex virus (HSV) types 1 and 2 and varicella-zoster virus (VZV). AFYIA Diagnostics has developed a qualitative screening test that allows the simultaneous identification of these viruses. Methods: The DIRASH kit is a multiplex HRM assay, based on the simultaneous detection of 4 viruses. The associated DISoft™ software is used to automatically analyze and interpret the HRM profiles obtained. Three studies were carried out to monitor cases of cutaneous-mucosal febrile vesicular eruptions: 1 conducted by CHU Montpellier from January 2021 to December 2022 during the clade II epidemic, and 2 conducted by INRB in Kinshasa from December 2022 to June 2024 with clade Ia and Ib . Each patient was screened by commercial or in-house PCRs. These samples were then retrospectively tested with the DIRASH. Results: 850 samples were retrospectively tested with the DIRASH kit to compare its clinical sensitivity with that of partner laboratory kits. In Montpellier, sensitivity was 100% for MPXV, 94% for VZV, and 98% for HSV-1 and HSV-2. INRB reported 98% for MPXV and 93% for VZV, showing the DIRASH kit ability to detect clades Ia, Ib, and II. This kit detected several undiagnosed co-infections (MPXV/HSV-1, MPXV/HSV2 and MPXV/VZV), with a consistent specificity of 100%. These results show that the clinical sensitivity of the PCRs from CHU and INRB is comparable to that of the DIRASH kit, with additional co-infections detected by the DIRASH kit, that would have been missed with the other PCRs, highlighting the benefit of syndromic diagnosis for febrile rashes. Conclusions: The DIRASH kit is rapid, reliable, transportable at room temperature, low-cost-multiplex test with automated result interpretation. Its ability to simultaneously detect viruses causing mucocutaneous vesicular eruptions meets the needs for differential diagnosis of MPXV, particularly in the DRC, where the epidemic is the largest in Africa, but also non-endemic countries. The kit is well-suited to strengthening diagnostic capabilities in the DRC, supporting patient management and epidemic control. 1198 Impact of Point-of-Care HIV-1 RNA Testing on Time to HIV Confirmation and ART Start in Buenos Aires Carina Cesar 1 , Guillermo Viloria 2 , Agustin Nava 1 , Ana Gun 1 , Luciano Maldonado 1 , Jonathan Garcia 1 , Victoria Viera 1 , Diego Salusso 1 , Felipe Bilbao 1 , Carla Petriglieri 1 , Julian Garcia 1 , Daniela Converso 1 , Mariana Kundro 2 , Maria I. Figueroa 1 , Pedro Cahn 1 1 Fundación Huésped, Buenos Aires, Argentina, 2 Hospital Ramos Mejia, Buenos Aires, Argentina Background: In Argentina, HIV diagnosis is confirmed through RNA-HIV (VL), usually performed in specialized referral laboratories. People need a second appointment to receive HIV confirmation (HIV-C), which is required to initiate antiretroviral therapy (ART). Time to HIV-C depends on laboratory and administrative factors. Shortening the diagnostic process is the first step towards implementing test and treat strategies. We hypothesized that point of-care (POC) technologies would reduce the time to results, the proportion of undelivered results, and the time to ART initiation compared with standard of care (SOC) in a middle-income country setting. Methods: We conducted a pilot study at 2 HIV testing centers in Buenos Aires: an NGO and a public hospital. People with a preliminary HIV diagnosis (HIV-PD) after a reactive HIV rapid test were enrolled. Phase 1 mimics SOC: blood samples for VL were sent to the laboratory for RT-PCR and HIV-C delivered in a second appointment. In phase2, POC, VL were locally processed with m-PIMA™ HIV-1/2 VL and HIV-C delivered subsequently. We evaluated time from HIV-PD to HIV-C and ART initiation as a continuous variable with Wilcoxon sum rank test. Categorical variables were tested with Chi-squared test or Fisher’s exact test. Linear regression models were fitted with an interaction term between center and strategy to evaluate whether the effect on time to HIV-C or ART initiation differs for each strategy between centers. Results: Between May 2023 and July 2024, 44 people with HIV-PD were enrolled in SOC and 47 in POC: median age 30 years (IQR: 26-36), 84% cisgender men, 9% transgender women, and 7% cisgender women. One person did not receive HIV-C in SOC vs none in POC. Median time to HIV-C was 16 days (14-23) in SOC vs 4 hours (3-34) in POC (p<0.001) (Fig. 1). ART was initiated in 80% (64-90) in SOC vs. 87% (74-95) in POC (p=0.5). ART initiation within the first 30 days was 66% (48-80) in SOC vs 85% (70-94) in POC (p=0.045). The interaction between strategy and center was not significant (p=0.0681) suggesting that time differences between SOC and POC do not differ between centers.

1196 Clinical Validation of iMune qPCR as a Novel Solution to CD4 Counting Off Dried Blood Spots Tracy M. Sungu 1 , Riffat Munir 1 , Denise Lawrie 2 , Wendy S. Stevens 3 , Lesley E. Scott 1 1 University of the Witwatersrand, Johannesburg, South Africa, 2 National Health Laboratory Service, Cape Town, South Africa, 3 National Health Laboratory Service, Johannesburg, South Africa Background: Quantification of CD4 T helper cells is important for tracking disease progression and monitoring opportunistic infections in people living with HIV (PLHIV). Discontinuation of two point of care (POC) CD4 tests, the PIMA CD4 (Abbott, IL, USA) and FACSPresto (Becton Dickinson Biosciences, San Jose CA), has created an unmet need for remote CD4 enumeration. We investigated CD4 counting off dried blood spot (DBS) specimens using novel epigenetic qPCR to potentially fill gaps in global health needs. Methods: Residual K3EDTA specimens from PLHIV (n=150) received for routine immunophenotyping, by PanLeucogating (PLG) technology performed on an AQUIOS flow cytometer (Beckman Coulter, Brea, CA), at the National Health Laboratory Service in Johannesburg, South Africa, were spotted (~70µl) onto Whatman 903 Protein Saver Cards (Merck, Darmstadt, Germany) and cobas® Plasma Separation Cards (140µl) (PSC, Roche Molecular, Pleasonton, CA). DBS and PSC (6mm punched) spots were manually extracted for DNA using the i.Mune CD4 Prep. This was followed by novel epigenetic quantification of CD4+ T-cells using the i.Mune CD4 Amp that included a GAPDH internal control (Epimune Diagnostics, Berlin, Germany). Real-time PCR was conducted on a QuantStudio 7 (Thermo Fisher Scientific, USA) and Cycle threshold (Ct) values converted into absolute CD4 counts using a data analysis tool. Results: The median PLG CD4 count of the specimens was 176 cells/µl (5-1361cells/µl), and the concordance correlation with the i.Mune CD4 qPCR absolute count off a DBS showed a moderate strength of agreement Pc=0.91 (95% confidence interval [CI] 0.88 to 0.94). The mean bias was -28.40 cells/ µl with a broad scatter (standard deviation [SD] of the bias =120.62cells/ µl), and overall agreement of 102% percentage similarity. A 5.9% (3/51) misclassification rate was observed at CD4<100 cells/µl and 12.5% (10/80) at CD4<200 cells/µl. A qPCR invalid rate was reported as 4.7% (7/150). The overall performance of the cobas® PSC i.Mune CD4 qPCR showed greater variance (Pc=0.16 [95% CI 0.054 to 0.26]) and requires a modified extraction protocol. Conclusions: In the absence of CD4 POCT and PLG CD4 immunophenotyping requiring testing within 5 days post venesection, the i.Mune CD4 could provide an alternative option off DBS collected from remote settings. qPCR also has the advantage of being performed on existing laboratory platforms and infrastructure. 1197 Screening of MPXV, VZV, HSV-1, and HSV-2 Causing Mucocutaneous Vesicular Rashes by Multiplex HRM-PCR Raphael Lumembe-Numbi 1 , Prince Akil-Bandali 2 , Fiston Cikaya-Kankolongo 1 , Chloé Musuamba-Kayembe 1 , Kinganda-Lusamaki Eddy 3 , Placide Mbala Kingebeni 1 , Franscisca Muyembe-Mawete 1 , Martine Peeters 4 , Angélique Rousseau 5 , Nans Picout 5 , Faustine Durand 5 , Nadege Nziza Trouchaud 5 , Steven Henry 6 , Vincent Foulogne 6 , Joany Guy 5 1 Institut Nationale de Recherche Biomédicale, Kinshasa, Democratic Republic of the Congo, 2 University of Kinshasa, Kinshasa, Democratic Republic of Congo, 3 University Montpellier, Montpellier, France, 4 Institut de recherche pour le développement (IRD), Marseille, France, 5 AFYIA Diagnostics, Grabels, France, 6 Pathogenesis & Control of Chronic & Emerging Infections (PPCEI), Montpellier, France Background: Since May 2022, over 27,000 cases of monkeypox (MPOX) have been reported in Europe where the disease is not endemic. In the Democratic

Poster Abstracts

CROI 2025 393