COMPARISON OF ENZYME-LINKED-IMMUNOSORBENT-ASSAY, INDIRECT IMMUNOFLUORESCENCE ASSAY, AND VIRUS ISOLATION FOR DETECTION OF RESPIRATORY VIRUSES IN NASOPHARYNGEAL SECRETIONS

Nasopharyngeal secretions obtained from 94 children with acute respiratory illness were examined for the presence of respiratory syncytial virus (RSV), adenovirus, and influenza virus type A by virus culturing (virus isolation technique [VIT]), immunofluorescence assay (IFA), and enzyme-linked immunosorbent assay (ELISA). Similar results were obtained in at least two tests for RSV, influenza virus type A, and adenovirus in 92 (97.9%), 88 (93.6%), and 88 (93.6%) cases, respectively. Both rapid virus detection methods showed good specificity for the diagnosis of these virus infections (greater-than-or-equal-to 90.7%) and were more sensitive than was VIT for RSV detection. In a more accurate statistical analysis, the indexes of agreement between VIT and ELISA were substantial for RSV (k = 0.69; z = 5.5; P < 0.0001), influenza virtus type A (k = 0.67; z = 5.3; P < 0.0001), and adenovirus (k = 0.71; z = 6.0; P < 0.0001), while it was almost perfect for RSV when ELISA was compared with IFA (k = 0.88; z = 5.7; P < 0.0001). Although the observed agreement was good in the comparison of these two tests for these three viruses (89%), the indexes of agreement were moderate in the comparison of IFA and VIT for RSV (k = 0.55; z = 2.0; P < 0.05), influenza virus type A (k = 0.42; z = 9.7; P < 0.0001), and adenovirus (k = 0.41; z = 6.5; P < 0.0001) and of ELISA and IFA for influenza virus type A (k = 0.55; z = 7.0; P < 0.0001) and adenovirus (k = 0.59; z = 6.8; P < 0.0001). All of the statistical evaluations demonstrated better agreement between ELISA and VIT for influenza virus type A and adenovirus.