ABSTRACT
BACKGROUND: In March 2004, the OraQuick rapid HIV antibody test became the first rapid HIV test approved by the US Food and Drug Administration for use on oral fluid specimens. Test results are available in 20 minutes, and the oral fluid test is non-invasive. From August 2004-June 2005, we investigated a sudden increase in false-positive results occurring in a performance study of OraQuick oral-fluid rapid HIV tests in Minnesota. METHODOLOGY/PRINCIPAL FINDINGS: In a field investigation, we reviewed performance study data on oral-fluid and whole-blood OraQuick rapid HIV test device lots and expiration dates and assessed test performance and interpretation with oral-fluid and whole-blood specimens by operators who reported false-positive results. We used multivariate logistic regression to evaluate client demographic and risk characteristics associated with false-positive results. Next, we conducted an incidence study of false-positive OraQuick rapid HIV tests in nine US cities and tested both oral-fluid and finger-stick whole-blood specimens from clients; reactive tests were confirmed with Western blot. Sixteen (4.1%) false-positive oral-fluid results occurred in the performance study from April 15, 2004 through August 31, 2004 with unexpired devices from six test lots among 388 HIV-uninfected clients (specificity, 95.9%; 95% CI: 93.4-97.6). Three test operators who had reported false-positive results performed and interpreted the test according to package-insert instructions. In multivariate analysis, only older age was significantly associated with false-positive results (adjusted odds ratio = 4.5, 95% CI: 1.2-25.7). In the incidence study, all valid oral-fluid and whole-blood results from 2,268 clients were concordant and no false-positive results occurred (100% specificity). CONCLUSIONS/SIGNIFICANCE: The field investigation did not identify a cause for the increase in false-positive oral-fluid results, and the incidence study detected no false-positive results. The findings suggest this was an isolated cluster; the test's overall performance was as specified by the manufacturer.
Subject(s)
AIDS Serodiagnosis/methods , False Positive Reactions , HIV Infections/diagnosis , HIV Seropositivity/diagnosis , HIV-1/immunology , Reagent Kits, Diagnostic/standards , Adult , Female , HIV Infections/epidemiology , HIV Infections/immunology , Humans , Male , Product Surveillance, Postmarketing/methods , Risk FactorsABSTRACT
OBJECTIVE: To evaluate the performance of a rapid HIV antibody test used with whole blood and oral fluid in settings where the test is likely to be used. DESIGN: In four separate studies, we compared the accuracy of the rapid test performed on whole blood and oral fluid specimens with the results of conventional HIV tests. METHODS: Oral fluid and whole blood from persons of unknown HIV status recruited from clinics, labor and delivery units, and outreach venues were tested with the OraQuick Advance rapid HIV-1/2 antibody test. Sensitivity and specificity were compared with results of the enzyme immunoassay (EIA) and Western blot algorithm used by the study sites. RESULTS: OraQuick sensitivity was 99.7% with whole blood and 99.1% with oral fluid from 327 persons who were HIV antibody positive by the conventional algorithm. OraQuick specificity was 99.9% with whole blood and 99.6% with oral fluid from 12 010 HIV-negative persons; EIA specificity was 99.7%. A cluster of 16 false-positive oral fluid tests occurred in one study, in which specificity was lower (99.0%) than in the other three studies (99.6-99.8%). CONCLUSIONS: In diverse settings in four studies, the OraQuick test showed high sensitivity and specificity for HIV antibody in whole blood and oral fluid specimens. Slightly more false-positive and false-negative results occurred with oral fluid than with whole blood, but performance with both specimen types was similar to, or better than, that of conventional EIAs.
Subject(s)
AIDS Serodiagnosis/methods , HIV Infections/diagnosis , Saliva/virology , Blotting, Western/methods , Enzyme-Linked Immunosorbent Assay/methods , Female , HIV Antibodies/analysis , HIV Infections/immunology , HIV-1/immunology , HIV-2/immunology , Humans , Predictive Value of Tests , Pregnancy , Reagent Kits, Diagnostic , Saliva/immunology , Sensitivity and SpecificityABSTRACT
Recent breakthroughs in technology have produced tests for HIV antibody that are highly accurate and easy to use and can give a preliminary result in 20 minutes or less. These rapid HIV tests will be used increasingly in labor and delivery wards, emergency departments, urgent care centers, and the primary care office. They have unique applications for healthcare worker exposures, military operations, public health venues, and developing countries. In this article, Drs Keenan, Keenan, and Branson discuss the advantages and limitations of rapid HIV testing in various settings.
