Uptake, acceptability and interpretability of 3-in-1 rapid blood self-testing for HIV, hepatitis B and hepatitis C.

INTRODUCTION: Early diagnosis is key to achieving the goal of eliminating transmission of HIV and hepatitis B and C. We assessed the uptake, acceptability and interpretability of self-testing using a 3-in-1 rapid diagnostic test (RDT) in facility-based services. METHODS: Stand-alone testing services were provided free of charge to consenting individuals aged ≥15 years in five facilities in northern Thailand. Clients were invited to choose between self-testing by fingerprick or venepuncture by a healthcare worker (HCW). In each facility, several clients could simultaneously self-test in separate private areas using TriQuik™ (Genlantis, San Diego, CA, USA), a single immunochromatographic cassette detecting HIV-1/2 antibody, hepatitis B surface antigen (HBsAg) and hepatitis C antibody (HCAb). An interactive program on a tablet computer was developed to collect socio-demographic, behavioural and satisfaction data and provide information to guide the self-test process, including video instructions, results interpretation and a picture of the cassette for immediate remote review by the HCW. When the HCW interpreted an HIV self-test as positive, the HCW collected blood by venepuncture for immediate confirmation. RESULTS: Between October 2020 and April 2022, 4119 clients presented for testing for the first time as part of the project. Of them, 3462 (84.0%) opted for self-testing. Among self-testers, 1801 (52.0%) were born female, the median age was 27 years (interquartile range, 22-36), 661 (19.1%) belonged to at least one key population and 2124 (61.4%) had never been tested for HIV; 3329 (99.8% of those who answered) reported being "very satisfied" or "satisfied" with the testing process. The proportions of test results interpreted as positive by self-testers among those interpreted as positive by HCWs were 95% for HIV-1/2 antibody, 95% for HBsAg and 78% for HCAb. CONCLUSIONS: These proportions were higher than those observed in a previous study evaluating another 3-in-1 RDT for HIV, HBsAg and HCAb, possibly due to the use of video instructions instead of paper-based instructions, lower prevalence and co-infection rates, or lower percentages of clients with low education level. Multiplex self-testing simplified and streamlined the service delivery process and was well accepted. HCW assistance proved to be essential in a limited number of cases.