Screening for HIV: can we afford the false negative rate

ABSTRACT

False negative results by screening assays for HIV represent an important and serious concern. We have assayed fourty-three western-blot confirmed positive sera from North and East Africa by five HIV-1 screening assays, four ELISAs [Virgo, Behring, Dupont, and Organon] and a particle agglutination test [Serodia]. Results indicated low sensitivities, ranging from .77 - .86. Concordance of positive results by all five screening assays was complete in only 51%. However, only a small portion of the African sera was responsible for the majority of inaccurate and discordant results.In addition, if western blot positivity had been defined by more stingent criteria [i.e. presence of p31 reactivity], sensitivities of the screening assays would have increased dramatically