Rapid viral diagnostic techniques.

Abstract

The application of viral diagnosis to clinical medicine is approaching a critical period in which greater emphasis will be placed on altering patient care as a result of viral identification. Although isolation of viruses in tissue culture is the "gold standard" to which all other methods of viral identification are compared, the expense in terms of cost and technical time required as well as the time necessary for specific viral isolation has severely limited the use of viral diagnosis in clinical medicine. The concomitant development of rapid viral diagnostic procedures with the increased availability of anti-viral therapy, promises to alter how patients will be managed in the future. The greatest emphasis for rapid viral diagnosis has been placed on viral detection directly from clinical specimens since these procedures eliminate the need to cultivate the virus. Methods for direct detection of viral antigens in clinical specimens include electron microscopy and a wide range of immunologic assays. The extraction of nucleic acid directly from clinical specimens and hybridization of this DNA to specific viral probes also provides for virus identification without the need to culture the virus. Currently, many of the rapid diagnostic procedures discussed are performed only in research laboratories. Over the next several years, however, methods of antigen detection using EIA procedures and detection of viral-specific nucleic acid promise to alter how we study and diagnose viral infections.