Twenty-two percent of HIV-positive test results by oral fluid rapid testing at two Whitman Walker clinics turned out to be either HIV negative or non-determinant when confirmed with blood tests, say researchers from a study presented at the National HIV Prevention Conference.
Akbar Shahkolahi, PhD, and his colleagues from the Whitman Walker Clinic in Washington, DC, set out to assess demographic differences and challenges using rapid HIV testing by oral fluid at two of their testing and care sites, the Elizabeth Taylor Medical Center (ETMC) and the Max Robinson Center (MRC).
At ETMC, 8,799 rapid HIV tests were conducted, of which 200 had a preliminary positive result. Of the 200, clinic workers were able to perform confirmatory Western blot testing using blood samples from 138 individuals. The clinic confirmed that 78 percent were HIV positive, whereas 22 percent were either HIV negative or indeterminate. Of those confirmed to be infected, 86 percent were male, 59 percent were black, 25 percent were white and 13 percent were Hispanic. Sixty-nine percent were gay or bisexual men.
At MRC, clinic workers conducted a total of 1,957 rapid HIV tests, of which 80 had a preliminary positive result. Only 36 people returned for confirmatory testing. Of those who had a confirmatory test, 83 percent were confirmed positive and 17 percent had either HIV-negative or indeterminate test results. Sixty -one percent of the clients at MRC were male, 98 percent were black and 61 percent were heterosexual.
Researchers did not offer an explanation for why so many preliminary HIV-positive results were later confirmed to be HIV negative or indeterminate. They did, however, concede that more work must be done to get people who initially test positive using rapid HIV assays to return for confirmatory testing.