Isolation and Characterization of Newcastle Disease Virus from Ostriches (struthio Camelus) in Egypt
- Hemat S. El-sayed, BENHA VETERINARY
Shakespeare in Othello said 'Be sure of it; give me ocular proof'. Perhaps this should become the motto of the Royal Microscopical Society because this philosophy has dominated diagnostic medicine, especially histology and microbiology since the days of the invention of the microscope by Leeuwenhoek in the late 1600s. Microbiology in particular has made use of the microscope, especially the light, fluorescence and electron microscopes, and it is within this context that the identification of viruses will be discussed. However, the mere identification of viruses in itself would be a futile exercise, a glass bead game, unless linked with the illnesses that they caused and with the treatment and management of the patient infected with them. To do this, the clinical virologists should aim to produce an aetiological diagnosis as rapidly as possible, usually within 2-3 hours, or certainly within 24 hours of the patient's admission to hospital and at a stage of the illness where this answer can still be useful in management and treatment. The two types of microscope which have played a vital role in the development of rapid virus diagnostic techniques have been the fluorescence microscope and the electron microscope and, though they are both still extremely useful in diagnosis, particularly the former, both are labour intensive and require skill in reading. In these days of mass production, where laboratories measure their prowess and their viability by the thousands of necessary (but often unnecessary) specimens that they examine during the course of a week, there has been a movement away from microscopical techniques to those where a machine will read results and unemotionally produce a tic-a-tape for the interested physician. This communication will attempt to indicate for various virus infections the main diagnostic procedures which are currently practiced for their identification. But the identification of a virus depends on immunohistochemistry and, in the case of immunofluorescence, on irnmunocytochemistry. Therefore, four factors are of great importance. These are (1) the quality of of the specimen, (2) the site from which it is obtained, (3) the quality of the diagnostic reagents and (4) the technique selected.