Background: The World Health Organization (WHO) self-testing guidelines recommends that people living with HIV (PLHIV) on antiretroviral therapy (ART) refrain from performing self-tests due to the risk of obtaining false negative results. We conducted a pilot study to assess the accuracy of one oral fluid and five blood based rapid diagnostic test (RDT) kits among PLHIV, of which four are designed for self-testing.
Methods: This was a cross sectional study among PLHIV on ART participating in two randomized clinical trials within the Wits Reproductive Health and HIV Institute treatment optimization program, in Johannesburg, South Africa. Participants were recruited using convenience sampling. All participants had been on ART for a minimum of 2 years. The research nurses performed the RDT serially, starting with the oral followed by the blood based. Two nurses blinded to the test kits read and interpreted the results. We assessed the agreement between the readers using the kappa statistic, computed the proportion of positive and negative test results by age, sex and duration on ART, and assessed the association using the Fisher''s exact test.
Results: 100 participants were recruited into the study; 67% of whom were females. Majority of the participants were ≤40 years (53%) and 41% had been on ART for ≥7 years. Overall, the two nurses had high agreement on the results reading with kappa ranging from 90 - 100% (p< 0.001). Nine (9%) of the patients had false negative results on at least one of the RDTs with a total of 16 false results in the 600 tests performed. Four participants had multiple tests with false results. False negative results was not associated by duration on treatment.
Conclusions: False negative results have serious implications for HIV Self-Testing Programmes. Retesting on ART could result in participants believing that they are ''cured'', especially in instances where multiple tests appear negative. False negativity may not be associated with length on time on ART, however further investigation on time to ART initiation from infection may play a role in antibody production.