Rapid Screening Tests for HIV-Reply

In Reply.—  In our article, we calculated the sensitivity and specificity of the rapid latex agglutination assay based on the results of 1220 serum samples in a test panel that had also been analyzed by enzyme-linked immunosorbent assay (ELISA) and Western blot testing. The performance of the latex assay in the field was then analyzed separately using serum samples from 1600 consecutive potential blood donors at Mama Yemo Hospital in Kinshasa, Zaire. The favorable results of the latex test in this African setting were discussed, but a calculated sensitivity and specificity were not provided, since not all 1600 serum samples had undergone Western blot analysis. Unfortunately, Drs Pachciarz and Barnes incorrectly state in their letter that Western blot tests were done only on African samples with positive latex agglutination tests. As clearly stated in the article, all of the Zairian samples were tested both by a commercially available licensed ELISA