Comparison of New HIV Rapid Test Kit Performance

Introduction: Early initiation of antiretroviral treatment is important in the management of HIV disease.  Testing is essential to identify HIV-positive clients so they can receive treatment and counseling on reducing high-risk behavior to prevent transmission of the infection to others.  Rapid testing methods, where the client receives the test results on the same day as specimen collection, often within minutes, have proven to be beneficial in the HIV-prevention effort.  Also, the test kits are less expensive than laboratory testing, are CLIA-waived, and are more feasible to be used in low-resource settings.  Having test kits available from more manufacturers would be beneficial to increase the supply of test kits and may result in test-kit choices that would be more closely matched to different testing venues.  The purpose of this study was to investigate the performance characteristics of HIV test kits that have not yet received FDA approval, and compare them to the performance of already approved test kits.

Methods: Whole blood was drawn, and oral specimens collected, from 1,065 participants in Los Angeles County, California.  Ethnicities included: American Indian/Alaska Native, Asian, African American, White, Hispanic and more than one race.  Behavioral Risk Groups (LA County definitions) included: people who inject drugs, women at sexual risk, men who have sex with men, and transgender.  Mean age was 40.4 years.  The protocol was approved by the local Institutional Review Board.  Blood was tested for HIV antibodies by both approved and experimental rapid tests and blood was sent to a contract laboratory for gold-standard (ELISA/Western Blot) HIV testing. 

Results: Five variations of the Dual Path Process (Chembio) tests had sensitivities from 97.6% - 100% for blood and 96.6% - 97.3% for oral specimens.  The Determine blood test had sensitivity of 94.1%.  The INSTI blood test had sensitivity of 94.4%, and the Multiplo blood tests had sensitivities from 89.6% - 93.0%.  All specificities were 99.5% - 100%. 

Conclusions: All test kits performed satisfactorily and progress is being made to obtain FDA approval for those kits not yet approved.  This should enable more choices for testing agencies in both the high- and low-resource settings which should result in more of those at risk being tested and being told their test results, which in turn should improve early treatment and prevention behavior.