Development of a more efficient algorithm for identifying false-positive reactivity results in a dengue virus immunoglobulin M screening assay

Of 2,692 sera screened for dengue virus immunoglobulin M by using a mu-capture enzyme-linked immunosorbent assay (ELISA), 954 had equivocal (index from 0.90 to 1.10) or positive (index of >1.10) results and were retested using a background subtraction (BS) ELISA that identifies screen false positives. No false positives were found among 427 sera with screen ELISA indices of >6.00; thus, retesting this specimen subset by BS ELISA is unnecessary.