CROI 2025 Abstract eBook

Abstract eBook

Poster Abstracts

Ag/Ab test results for specific populations may also facilitate test interpretation and recommendations for future HIV testing.

recent infection surveillance data and HIV testing services (HTS) data to identify potential signals of ongoing HIV acquisition. Methods: In Malawi, recent infection surveillance uses a recent infection testing algorithm (RITA), combining a rapid test for recent infection and viral load testing. RITA results for clients ≥15 years old from October 2022 to June 2023 from 287 facilities were analyzed using a proxy ‘at-risk’ populations estimated as those testing HIV-negative plus those classified as RITA recent. In addition, for the same facilities and period, routine HTS data of HIV testing yield (the proportion of new positives among those who had a HIV test) were analyzed. Both analyses were adjusted by sex and utilized a Poisson probability model to identify one or more facilities with a significantly higher (p<0.01) observed rate of recent infection than the expected with a maximum cluster radius of 10km using SaTScan software. A side-by-side comparison of the geographic distribution of both sets of signals of facilities was done using ArcGIS Software. Results: Among 20,093 persons newly diagnosed with HIV, 534 (2.0%) tested RITA recent; of these, 76% were female and 24% male. In the same period, 1,065,601 persons were tested for HIV; HIV testing yield was 2.5%. Using HTS data, 60% of the newly diagnosed persons were female and 40% were male. SaTScan identified two areas of elevated rates of recent infection while, 29 areas of elevated rates of HIV testing yield were identified. Results showed that one of the two signals of elevated HIV acquisition identified using RITA results overlaps with a signal identified using HTS yield data. Conclusions: HTS yield data identified more potential signals of elevated HIV transmission than recent infections likely due to repeat testing or late diagnoses. Additional triangulation of surveillance and program data and use of unique identifiers in the program may be explored to improve use of surveillance data to identify areas with ongoing HIV acquisition. 1195 Preferences for HIV Testing Technologies in Seattle, Washington: A Mixed-Methods Study Lauren R. Violette 1 , Lisa A. Niemann 2 , Maggie Murphy 2 , Andy Cornelius-Hudson 2 , Carl Capili 2 , Joanne Stekler 2 1 Harvard Medical School, Boston, MA, USA, 2 University of Washington, Seattle, WA, USA Background: Understanding preferences for HIV testing technologies could increase uptake. We conducted a mixed-methods study to explore testing preferences among participants in the GAIN Study. Methods: Between June 2023-May 2024, we enrolled a convenience sample of persons seeking HIV testing, post-exposure prophylaxis, or pre-exposure prophylaxis (PrEP) care at a community testing site or HIV clinic in Seattle, WA. We used convergent parallel mixed-methods design with a discrete choice experiment (DCE) (N=142) and in-depth interviews (N=20). Participants were randomized to one of three blocks of 12 DCE questions. For each question, participants selected their most and least preferred option from three hypothetical tests with four attributes (specimen type, window period, time to results, and likelihood of false positive results) having three or four levels. Preference weights (PW) and relative importance were calculated using multinomial logistic regression. Greater PWs indicate stronger preference. Semi-structured interviews were analyzed using a Rapid Assessment Process. Results: Most survey participants were cisgender men (70%) and white (57%). Reasons for HIV testing included regular testing (49%), new partner (33%), PrEP initiation (10%), and HIV/STI symptoms or exposure (8%). One-third were on PrEP. A 0.1% false positive rate (PW=1.06), 2-week window period (PW=0.58) and fingerstick specimen (PW=0.18) were the most preferred test characteristics ( Figure ). Faster tests were preferred with no difference between 20-minute and 1-hour tests (PW=0.13 and 0.14). Likelihood of false positives had highest relative importance (54%), and specimen type was the least important attribute (8%) to decision-making. Qualitative data was consistent with DCE findings. Test accuracy was the most important attribute although there was conflation of specificity and sensitivity and confusion about the window period. Participants preferred faster tests to reduce anxiety while waiting for results, especially when concerned about recent exposures. There was higher degree of trust in blood-based tests which were preferred over oral fluid tests. Conclusions: Participants preferred fast, accurate blood-based tests with shorter window periods, but qualitative data identified misconceptions about HIV test properties. HIV testing should be paired with education to ensure persons understand results, and device development should focus on specificity and window period sensitivity while keeping time to results under one hour.

1193 Use of DNA Profiling to Resolve Discrepant HIV Tests in the Setting of Injectable Cabotegravir PrEP Jessica M. Fogel 1 , M. Ali Salih 2 , Kathy Haddaway 3 , Mark A. Marzinke 1 , Christi Marshall 3 , Zhe Wang 4 , Vanessa Cummings 1 , Estelle Piwowar-Manning 1 , James F. Rooney 5 , Marybeth McCauley 6 , Beatriz Grinsztejn 7 , Raphael J. Landovitz 8 , Susan H. Eshleman 1 , for the HPTN 083 Study Team 1 The Johns Hopkins University School of Medicine, Baltimore, MD, USA, 2 DNA Reference Laboratory, Inc, San Antonio, TX, USA, 3 The Johns Hopkins Hospital, Baltimore, MD, USA, 4 Fred Hutchinson Cancer Center, Seattle, WA, USA, 5 Gilead Sciences, Inc, Foster City, CA, USA, 6 Family Health International 360, Durham, NC, USA, 7 Instituto Nacional de Infectologia Evandro Chagas, Rio de Janeiro, Brazil, 8 University of California Los Angeles, Los Angeles, CA, USA Background: In clinical trials, discordant test results can complicate participant management and study endpoint determination. HIV diagnosis can be challenging when long-acting cabotegravir (CAB-LA) is used for HIV pre-exposure prophylaxis (PrEP) since HIV antigen, antibody, and RNA levels are often low. HIV assays can also revert from reactive/positive to non-reactive/ negative in this setting. We evaluated a case where discrepant HIV test results were obtained for a participant receiving CAB-LA in the HIV Prevention Trials Network (HPTN) 083 trial. Methods: The study site performed HIV rapid testing and antigen/antibody (Ag/Ab) testing; infections were confirmed with antibody and RNA tests. Retrospective testing was performed at the HPTN Laboratory Center using an Ag/Ab test, a discriminatory test, and an HIV RNA test. Plasma cabotegravir (CAB) was quantified via liquid chromatography-tandem mass spectrometry. Serologic ABO and Lewis testing was performed at the Johns Hopkins Hospital Transfusion Medicine Laboratory. Short tandem repeat DNA profiling was performed at the DNA Reference Laboratory using the Promega PowerPlex Fusion System and Promega PowerPlex Y23 System. Results: The participant had 19 CAB-LA injections and then received 16 months of tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) PrEP before enrolling in the open label extension of HPTN 083 (OLE). The participant received one CAB-LA injection in the OLE and then restarted TDF/FTC PrEP after an injection site reaction. All HIV test results, including an HIV RNA test, were negative/non reactive at the first OLE visit; 26 days later, the HIV rapid test was non-reactive, the Ag/Ab test was reactive, the discriminatory test was positive, and the viral load was 2,588 copies/mL. All results at later visits were non-reactive/negative. Retrospective test results were consistent with the results from the study site. CAB concentrations were as expected based on the timing of injections. ABO groups, anti-A and anti-B titers, and Lewis phenotypes were the same for all samples tested. DNA profiling revealed that plasma from the visit with positive HIV test results was contaminated with DNA from an unrelated individual. Conclusions: Detailed laboratory investigations may be required to explain unexpected or discrepant test results. In this case, DNA profiling explained the discrepant HIV test results, which helped guide clinical management of the study participant and excluded the case as a primary study endpoint. 1194 Can HIV Testing Data and Recent HIV Infection Surveillance Identify Similar Signals of Transmission? Misheck Luhanga 1 , Joe Theu 2 , Melissa Arons 3 , Reno Stephens 3 , Davie Chalira 2 , James L. Tobias 4 , Alinune Kabaghe 1 , Danielle Payne 3 , Khumbo Namachapa 5 , Evelyn Kim 3 , Nellie Wadonda 1 1 US Centers for Disease Control and Prevention Lilongwe, Lilongwe, Malawi, 2 I-TECH Malawi, Lilongwe, Malawi, 3 Centers for Disease Control and Prevention, Atlanta, GA, USA, 4 Peraton, Aurora, CO, USA, 5 Government of Malawi Ministry of Health, Lilongwe, Malawi Background: Although there has been much progress controlling the HIV epidemic in Malawi, identifying, and understanding ongoing HIV acquisition is needed for targeted HIV control efforts. We analyzed facility-based HIV

Poster Abstracts

CROI 2025 392