Detection of precytopathic effect of enteroviruses in clinical specimens by centrifugation-enhanced antigen detection

Rapid enterovirus detection is important for decisions about antibiotic adm inistration and length of hospital stay. The efficacy of rapid antigen dete ction-cell culture amplification (Ag-CCA) was evaluated with monoclonal ant ibodies (MAbs) 5-D8/1 (DAKO) and Pan-Enterovirus clone 2E11 (Chemicon) with 10 poliovirus, echovirus, and coxsackievirus type A and B stock isolates a nd College of American Pathologists check samples. By using Ag-CCA technolo gy, MAb 2E11 was more sensitive than 5-D8/1 at detecting a greater number o f stock isolates at or past tube (cytopathic effect [CPE]) culture (TC) end points. The efficacy of Ag-CCA in the clinical setting was subsequently co nfirmed with 273 consecutively freshly collected nasopharyngeal aspirate or swab specimens, rectal swab, and cerebrospinal fluid specimens during the 1999 enterovirus season. All specimens were tested by Ag-CCA in parallel wi th rhesus monkey kidney (RhMk), MRC-5, and A549 conventional TCs. Approxima tely 60% of field specimens were additionally tested with Hep-2 and HNK con ventional TCs. Sixty-two percent of the clinical specimens tested were Ag-C CA positive after 48 h. Among 51 isolates, the mean time to CPE or culture confirmation was 5.5 days (range, 2 to 18 days). After 48 h, Ag-CCA achieve d sensitivity, specificity, and positive and negative predictive values of 62, 100, 100, and 93%, respectively. During the same period, TC-CPE display ed test parameters of 12, 100, 100, and 85%, respectively. After 5 days, th e sensitivity and specificity of Ag-CCA increased to 92 and 98%, respective ly. Within the same period, isolation attained sensitivity and specificity of 52 and 100%, respectively. Although Ag-CCA displayed slightly reduced se nsitivity and reduced specificity compared with conventional cell culture a fter 14 days, the markedly superior 48-h enterovirus Ag-CCA detection rate supports incorporation of this assay into the routine clinical setting.