Direct detection of rhinoviruses by an enzyme-linked immunosorbent assay

This paper describes the first enzyme-linked immunosorbent assay for the detection of rhinovirus antigens in clinical specimens (nasal washings), either directly or following overnight cell culture amplification. The assay takes approximately 48 hours to perform and utilizes the same rabbit antirhinovirus hyperimmune serum as both the capture and detecting antibody. The latter has been biotin-labelled and is detected via a streptavidin beta-galactosidase preformed complex. This new assay has been found to be very sensitive, detecting human rhinovirus (HRV)-EL and HRV-2 at titres as low as 10(1.8) TCID50 100 microliter-1 and less than 10(1)TCID50 100 microliter -1, respectively. Furthermore, when 57 different human rhinovirus serotypes were tested in both the HRV-EL and HRV-2 ELISA systems a total of 49 (86%) were found to be cross-reactive. Of 36 clinical specimens tested by virus isolation, cell-culture-amplified (CCA) ELISA, and direct ELISA, 15 were positive by isolation, 11 by CCA-ELISA, and 11 by direct ELISA. The overall correlation of the CCA and direct ELISA techniques with virus isolation was found to be 88.9% and 66.7%, respectively. The present study demonstrates that the ELISA system developed is a sensitive technique for the diagnosis of rhinovirus infections.