Enzyme immunoassays for the detection of microbial antigens in body fluids: An overview

Traditionally, the diagnosis of infectious diseases has been accomplished by the isolation of the infecting microorganisms in pure culture. While classical cultivation systems are widely utilized for microbial diagnosis they suffer from a number of limitations. The most important limitation is that an extended period of time is often required before an infecting organism can be grown in sufficient quantitites so that it can be recognized and identified. This is particularly a problem in the case of viruses and slow growing bacteria where the time required for growth and specific identification can be sufficiently long so that the information derived from such cultivation is not of use to the clinician caring for the patient or to the infection control officer attempting to prevent the spread of the infection within an institution. In addition, the reagents and equipment required for cultivation restrict the performance of microbiological techniques to laboratory situations. Diagnostic environments are particularly limited in the case of viral diagnosis since viruses require the availability of primary cells or continuous cell lines as well as sterile areas and reagents. These requirements limit viral diagnosis to central laboratory facilities and research laboratories (1–4).