Diagnostic virology--the need for electron microscopy: a discussion paper.

Abstract

During the European Virology 2000 meeting in Glasgow in September 2000, we organised a Workshop on the Use of Electron Microscopy (EM) in Diagnostic Virology. Those present, discussed the current and future uses of EM and how it might be provided in diagnostic services increasingly under financial pressures and bombarded with an increasing number of commercially produced diagnostic kits. Since the audience at the Workshop was largely those with an interest in EM, we felt that the issues raised would interest a wider one because there seems to have been no serious debate on the merits and deficits of diagnostic EM. In this review of the issues, only transmission EM (TEM) has been considered, and mainly negative contrast, because scanning EM (SEM) does not have a practical place in diagnostic work, at least for the present, and thin-sectioning is not appropriate for routine virus diagnosis. Much of what we have written concerns the diagnosis of human disease, but EM is also used in veterinary practice as well and faces similar problems. Where necessary, we try to draw attention to unique veterinary applications. Humans have five senses — sight, hearing, touch, taste and smell. Of these, the most precise is sight, and we recognise immediately a variety of objects and people, often at some distance, even when we might have difficulty in explaining exactly why we were so certain of our identification and, even more, of proving it. Not surprisingly, we always want to know what a new virus looks like, to help cement its identity in our memory, and the only way we can ‘see’ a virus is with an EM. Virtually all those present at the Glasgow workshop agreed that EM should be available as a component of a diagnostic service, but there was less agreement on how this should be done. Less than 20 years ago, EM was the latest thing — all diagnostic laboratories either regarded them as essential (if they had one) or hoped to get one if they didn’t. Now there is much less enthusiasm for having one’s own instrument, but the virologists at the meeting still wanted the facility as a backstop. How and why has this change * Corresponding author. E-mail address: biels@hamburg.beiersdorf.com (S.S. Biel).