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

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.

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.

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.

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.