CROI 2025 Abstract eBook

Abstract eBook

Poster Abstracts

1185 Validation of a National HIV Testing Eligibility Screening Tool in Tanzania Galal N. King'ori 1 , Robert Nelson 2 , Steve J. Gutreuter 2 , Amy Medley 2 , Catherine J. Nnko 3 , Frank Msangi 4 , Joyce Thomas 5 , James J. McOllogi 6 , Moses Bateganya 7 , Zeye M. Nkomela 6 , Upendo Kategile 7 , George S. Mgomella 1 , Neema Mlole 8 , Oscar E. Rwabiyago 1 1 US Centers for Disease Control and Prevention Dar es Salaam, Dar es Salaam, United Republic of Tanzania, 2 Centers for Disease Control and Prevention, Atlanta, GA, USA, 3 Elizabeth Glaser Pediatric AIDS Foundation, Dar es Salaam, Tanzania, 4 Management and Development for Health, Dar es Salaam, United Republic of Tanzania, 5 ICAP at Columbia University in Tanzania, Dar es Salaam, Tanzania, 6 Tanzania Youth Alliance, Dar es Salaam, United Republic of Tanzania, 7 US Agency for International Development Tanzania, Dar es Salaam, United Republic of Tanzania, 8 President's Office for Regional and Local Government Authority, Dodoma, Tanzania Background: In 2020, Tanzania introduced a 16-question screening tool to determine adult eligibility for HIV testing services (HTS). This validation study compares the characteristics of the current tool to a) an optimized tool and b) HIV self-testing (HIVST). Methods: From March to June 2024, adults aged ≥15 years with unknown HIV status seeking care were enrolled at 32 health facilities in Tanzania. The current national screening tool was administered, and all participants were tested for HIV regardless of eligibility screening outcome. Demographic information, screening responses, and HIV test results were collected. Eligibility for HTS was defined as ≥1 positive response among 16 screening questions. An optimized screening tool was developed using regularized logistic regression to identify the most predictive of the 16 screening questions and optimal weighting (1 to 3 points), with a total score ≥2 as the threshold for HTS eligibility. Sensitivity, specificity, positive and negative predictive values (PPV, NPV), and 95% confidence intervals were generated for both screening tools. PPV and NPV were calculated based on manufacturer’s reported sensitivity and specificity for HIVST. Results: We enrolled 23,444 participants; median age was 32 years (interquartile range: 24-43 years), and 13,715 (58.5%) were women. HIV was diagnosed in 356 (1.5%) participants, with higher prevalence among women (1.7%) compared to men (1.2%) and persons aged ≥35 years (2.0%) compared to persons aged <35 years (1.1%). Of participants, 22,228 (94.8%) screened eligible for HTS using the national tool (97.8% sensitivity, 5.2% specificity). Slightly fewer (22,097; 94.3%) screened eligible for HTS using the optimized tool, which had similar characteristics to the national screening tool (97.8% sensitivity, specificity 5.9%). Using HIVST for screening yielded 402 (1.7%) participants eligible for HTS, including all in whom HIV was diagnosed. Conclusions: The national and optimized tools had high sensitivity but low specificity resulting in almost all participants screening eligible for HTS. Both tools misclassified some persons as ineligible for HTS who were later diagnosed with HIV. HIVST was more efficient than the two screening tools, resulting in fewer individuals screening eligible for HTS but identifying all persons in whom HIV was diagnosed. Further econometric and qualitative analyses are needed to determine the implications of these results on HTS eligibility screening policy.

1186 Transfusion Risk of HIV, HBV, and HCV in Low- and Middle-Income Countries Without Nucleic Acid Testing Jodie L. White 1 , Dorothy Kyeyune-Byabazaire 2 , Ezra Musisi 2 , Paula Saa 3 , Jamel Groves 3 , Jeffrey M. Linnen 4 , Ronnie Kasirye 5 , Irene Lubega 5 , Thomas C. Quinn 6 , Heather A. Hume 7 , Evan M. Bloch 1 , Susan L. Stramer 8 , Mary G. Fowler 1 , Philippa Musoke 5 , Aaron A. R. Tobian 1 1 The Johns Hopkins University School of Medicine, Baltimore, MD, USA, 2 Uganda Blood Transfusion Service, Kampala, Uganda, 3 American Red Cross, Washington, DC, USA, 4 Grifols Diagnostic Solutions, Inc, Emeryville, CA, USA, 5 Makerere University–Johns Hopkins University Research Collaboration, Kampala, Uganda, 6 The Johns Hopkins University, Baltimore, MD, USA, 7 University of Montreal, Montreal, Canada, 8 Independent Consultant, Gaithersburg, MD, USA Background: Nucleic acid testing (NAT) is a highly sensitive detection method routinely used to screen donated blood for human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) in high-income countries. Despite this technology being available for decades, few low- and middle-income countries (LMIC) in sub-Saharan Africa (SSA) have implemented NAT. We aimed to quantify the risk to transfusion recipients this disparity in access to screening technology causes using data from Uganda, which implemented NAT in July 2022. Methods: Units collected by the Uganda Blood Transfusion Service from October 2019 to June 2022 were tested for HIV, HBV and HCV on the Abbott ARCHITECT platform as part of routine serologic screening in Uganda. The units were retested by the American Red Cross in 2023 using a combination of individual unit NAT (Grifols’ Procleix UltrioPlex E Assay [UPE], detecting HIV 1,-2, HBV, and HCV simultaneously) and serology (Abbott Alinity s). Standard confirmatory methods were used for samples discordant between UPE/Alinity s. Pathogen-specific results were compared between ARCHITECT and UPE/ Alinity s. Samples testing nonreactive by ARCHITECT but reactive by UPE/Alinity s were summarized by type of reactivity: seropositive only, NAT-positive only and seropositive and NAT-positive. The number of potentially infectious units (i.e., NAT-positive only or seropositive and NAT-positive) per 100,000 that were nonreactive by the ARCHITECT were estimated. nonreactive on the ARCHITECT but reactive on UPE/Alinity s, 8 were potentially infectious, equating for 195.5/100,000 units. Among 29 units that were HBV nonreactive on the ARCHITECT but reactive on UPE/Alinity s, 27 were potentially infectious, equating to 666.0/100,000 units. Among 16 units that were HCV nonreactive on the ARCHITECT but reactive on UPE/Alinity s, 2 were potentially infectious, equating to 49.0/100,000 units. Conclusions: The implementation of NAT for donor screening in Uganda, which issues >300,000 units to healthcare facilities a year, has likely prevented thousands of infectious units from entering the blood supply. However, Uganda is one of only a small number of LMIC in SSA that has been able to enact this change. Policies that ensure equitable access and distribution of donor screening tools should be enacted to support safe blood transfusions globally. Results: Data from both the ARCHITECT platform and the UPE/Alinity s platforms were avilable for 4,123 units. Among 9 units that were HIV

Poster Abstracts

1187 Clinical Features Are Poor Identifiers of Advanced HIV Disease in the Absence of CD4 Quantification Phoebe Allebone-Salt 1 , Thomas S. Harrison 1 , Nelesh P. Govender 2 , Joseph N. Jarvis 3 , Rachel Wake 4 1 St George's University of London, London, UK, 2 University of the Witwatersrand, Johannesburg, South Africa, 3 London School of Hygiene & Tropical Medicine, London, UK, 4 St George's University Hospitals NHS Foundation Trust, London, UK Background: Advanced HIV disease (AHD) is defined by WHO as CD4 count <200 cells/ µL or WHO stage 3-4, triggering a series of interventions to identify and treat opportunistic infections (OIs) and rapidly initiate ART. Access to CD4 count testing is declining as a ‘test and treat’ approach to HIV is adopted, and clinical features increasingly relied on to guide OI screening. We hypothesise

CROI 2025 389