Low rate of false-positive results with use of a rapid HIV test.
BACKGROUND
Occupational exposure to human immunodeficiency virus (HIV) is an important threat to healthcare workers. Centers for Disease Control and Prevention guidelines recommend prompt institution of prophylaxis. This requires (1) immediate prophylaxis after exposure, pending test results that may take more than 24 hours in many hospitals; or (2) performance of a rapid test. The Single Use Diagnostic System (SUDS) HIV-1 Test is used to screen rapidly for antibodies to HIV type 1 in plasma or serum, with a reported sensitivity of more than 99.9%. We used this test from January 1999 until September 2000, when it was withdrawn from the market following reports claiming a high rate of false-positive results.


METHODS
We reviewed the results of postexposure HIV testing during 21 months.


RESULTS
A total of 884 SUDS tests were performed on source patients after occupational exposures (883 negative results, 1 reactive result). The results of repeat SUDS testing on the reactive specimen were also reactive, but the results of enzyme immunoassay and Western blot testing were negative. A new specimen from the same patient showed a negative result on SUDS testing. This suggested a specificity of 99.9%. In the 4 months after SUDS testing was suspended, there was 1 false-positive result on enzyme immunoassay for 1 of 132 source patients (presumed specificity, 99.2%).


CONCLUSIONS
Use of the SUDS test facilitated rapid and accurate evaluation of source specimens, obviating unnecessary prophylaxis.
Salgado
Cassandra D
CD
Department of Medicine, University of Virginia Health System, Charlottesville 22908, USA.
Flanagan
Heidi L
HL
Haverstick
Doris M
DM
Farr
Barry M
BM
D005189:False Positive Reactions; D015658:HIV Infections / Q000175:diagnosis*; D006282:Health Personnel; D006801:Humans; D007124:Immunoenzyme Techniques; D016273:Occupational Exposure; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity
D011933:Reagent Kits, Diagnostic