Feasibility, Acceptability, and Test Performance of Point-of-Care Nucleic Acid Tests for HIV Testing and Viral Load...

With shorter window periods than serologic point-of-care (POC) tests and faster turnaround than laboratory-based nucleic acid tests (NAT), POC NATs could improve early detection of HIV. Furthermore, semiquantitative POC NAT may provide real-time monitoring for persons with HIV. There have been limited evaluations of POC NAT implementation in the United States.

This paper describes the protocols and procedures used to evaluate the acceptability and feasibility of POC NAT implementation and test performance in clinical and community settings in Seattle, Washington.

The Greater Access and Impact through POC NAT (GAIN) study was a Centers for Disease Control and Prevention-funded study that enrolled participants at a Ryan White-funded, hospital-based clinic (Madison Clinic) and a community site (Seattle's LGBTQ+ Center [the Center]). Persons seeking HIV testing, nonoccupational postexposure prophylaxis, or pre-exposure prophylaxis (PrEP) enrolled at either site received the standard of care plus the SAMBA II HIV-1 Qualitative Whole Blood Test (SAMBA Qual) and pooled laboratory HIV NAT, and persons with HIV enrolled at the Center received standard-of-care sexually transmitted infection testing plus the SAMBA II HIV-1 Semiquantitative Whole Blood Test (SAMBA Semi-Q) and laboratory viral load testing. Persons with HIV from Madison Clinic were recruited into a randomized clinical trial (RCT) to compare the clinical standard of care with the addition of the SAMBA Semi-Q (backed up by Food and Drug Administration-approved laboratory NAT). All participants completed a demographic survey during their study visit and contributed prospective data via electronic medical records. Subsets of participants from each group were invited to complete a postvisit acceptability survey and participate in an individual interview. Patient flow was observed at Madison Clinic to assess the impact of POC testing on clinic visit timing.

From January 2022 to December 2024, 733 participants completed 753 GAIN research visits. Of those, 491 visits were completed by 489 participants seeking HIV testing and/or PrEP at the Center, and 61 visits were completed by 43 participants seeking HIV testing, nonoccupational postexposure prophylaxis, and/or PrEP at Madison Clinic. Test result data will assess test performance, with analyses anticipated in 2027. Seven people with HIV were enrolled at the Center, and 194 people with HIV were enrolled in the Madison Clinic RCT. Data from patients with HIV at Madison Clinic will be used to conduct a survival analysis evaluating the impact of POC NAT on time to viral suppression and to assess test performance, with analyses anticipated in 2026. In-depth acceptability surveys were completed by 193 participants, and 41 interviews were conducted. These data will contribute to qualitative and mixed methods analyses, which are anticipated in 2026. Time-and-motion observations conducted in 2021 and 2023 included 47 patients; results are anticipated in 2026.

The GAIN study is an important evaluation of POC NAT implementation in the United States in community and clinical care settings for HIV diagnosis and viral load monitoring. Results will be reported in future publications.