Streamlining HIV testing for HIV preexposure prophylaxis.
HIV-testing algorithms for preexposure prophylaxis (PrEP) should be optimized to minimize the risk of drug resistance, the time off PrEP required to evaluate false-positive screening results, and costs and to expedite the start of therapy for those confirmed to be infected. HIV rapid tests (RTs) for anti-HIV antibodies provide results in less than 1 h and can be conducted by nonlicensed staff at the point of care. In many regions, Western blot (WB) testing is required to confirm reactive RT results. WB testing, however, causes delays in diagnosis and adds expense. The iPrEx study evaluated the safety and efficacy of daily oral emtricitabine-tenofovir disoproxil fumarate among HIV-seronegative men and transgender women who have sex with men: HIV infection was assessed with two RTs plus WB confirmation, followed by HIV-1 plasma viral load testing. During the iPrEx study, there were 51,260 HIV status evaluations among 2,499 volunteers using RTs: 142 (0.28%) had concordant positive results (100% were eventually confirmed) and 19 (0.04%) had discordant results among 14 participants; 11 were eventually determined to be HIV infected. A streamlined approach using only one RT to screen and a second RT to confirm (without WB) would have had nearly the same accuracy. Discrepant RT results are best evaluated with nucleic acid testing, which would also increase sensitivity.
Investigaciones Médicas en Salud, Lima, Peru jguanira@inmensa.org.
Juan V
http://orcid.org/0000-0002-2746-3086
JV
Guanira
University of California, San Francisco, California, USA.
Teri
T
Leigler
University of Sao Paulo, Sao Paulo, Brazil.
Esper
E
Kallas
Praca Onze, Rio de Janeiro, Brazil.
Mauro
M
Schechter
NIH/NIAID, Bethesda, Maryland, USA.
Usha
U
Sharma
University of California, San Francisco, California, USA.
David
D
Glidden
University of California, San Francisco, California, USA Gladstone Institutes, San Francisco, California, USA.
Robert M
RM
Grant
D000328:Adult; D000465:Algorithms; D019380:Anti-HIV Agents / Q000627:therapeutic use; D005260:Female; D005500:Follow-Up Studies; D015658:HIV Infections / Q000175:diagnosis* / Q000517:prevention & control / Q000821:virology*; D015497:HIV-1 / Q000145:classification*; D006801:Humans; D007118:Immunoassay / Q000379:methods; D008297:Male; D016133:Polymerase Chain Reaction; D065129:Pre-Exposure Prophylaxis; D011292:Premedication; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D019380:Anti-HIV Agents