Rapid Testing Algorithm Performance in a Low-Prevalence Environment. (May 2020)

• Record Type: Journal Article
• Authors: Martin, Eugene G.; Cornett, Julia; Mohammed, Debbie Y.; Salaru, Gratian
• Is Part Of: Sexually transmitted diseases. Volume 47(2020)Supplement 1 5S
• Publication Date: 2020-05
• Subjects: Sexually transmitted diseases -- Periodicals; Sexual health -- Periodicals; 616.951005
• DOI: 10.1097/OLQ.0000000000001138
• Languages: English
• ISSNs: 0148-5717

Abstract

Abstract : Background: The performance of a statewide HIV rapid test algorithm (RTA) in a low-prevalence setting (0.71%) was examined for 3 years. Methods: An initial rapid screening by HIV-1/2 Ag/Ab Combo test (RT#1) with Ab verification using a second, different rapid test (RT#2) was conducted. Clinic referral was immediate for antigen- only –positive screens. Antibody-positive screens were confirmed by RT#2. Specimens were collected following discordant RTA results (initially Ab-POS by RT#1, but negative on RT#2) and tested in accordance with the current Centers for Disease Control and Prevention/Association of Public Health Laboratories–based HIV diagnostic algorithm supplemented by a quantitative viral load whenever possible. Results: Of 310, 785 tests performed, 2400 preliminary positive screens were identified; 2191 (91.8%) confirmed by RT#2. Of 13 Determine Combo AG-POS results identified, only 1 confirmed positive. Of the remaining 196 discordant results, 182 (92.9%) were uninfected, including 13 with AG-POS/AB-POS results. Of 14 true positives (7.1%) identified after discordant RTA results, the average quantitative HIV-1 viral load was 277, 385 copies/mL, but 5 (35.7%) of 14 had viral loads <1000 copies/mL. Among the 2191 "presumptive positive" by RTA, 3 false-positive (FP) RTAs were reported (both rapid tests having positive results, while the HIV-1/2 Ag/Ab assay and quantitative HIV-1 viral load showed negative results). Conclusions: The RTA was effective in predicting true-positive HIV test results and facilitating linkage to care. Discordant results were infrequent. Fingerstick DC Ag detection identified a single early infection. Many discordant cases that were subsequently positive were associated with viral loads <1000 copies/mL. Abstract : For 3 years, a statewide rapid test algorithm screened 310, 785 persons in approximately 150 sites and presumptively confirmed 91.8% of preliminary positive screens; 196 were discordant, of which 92.9% were uninfected.