comparative study for screening and confirmation of antibodies to human immunodeficiency virus

ABSTRACT

Four commercially available ELISA kits and three confirmatory tests were evaluated for human immunodeficiency virus [HIV] screening and confirmation on sera from four groups of Saudi patients [1] 1000 blood domors; [2] 123 patients at high-risk for acquired immunodeficiency syndrome [AIDS] [20 hemophiliacs, 80 thalassemics, and 23 patients with generalized lymphadenopathy]; [3] 200 carrieres of hepatitis B surface antigen; and [4] 170 patients attending the veneral disease [VD] clinic. In all four groups of patients, reactivity was most common with the Abboutt enzyme-linked immunosorbent assay [ELISA] screening kit compared with ELISA screening kits from three other manufacturers. A high rate o reactivity, particularly with the Abbott ELISA [13/170] was seen with patients from the VD clinic. Only eight sample were reactive by all four ELISA screening assays, however, and of these, only three were definitely positive as judged by a confirmatory immunofluorescent test, the Abbott ELISA confirmatory test, and the Western blot. The variability of these results strongly indicates that retesting is necessary to establish persistent reactivity followed by confirmatory testing. Repeat testing by a different commercial ELISA assay dose not replace the essential confirmatory step