Rapid developments in the subject have made a new edition necessary. During this short period, new infectious diseases have emerged or re-emerged in new forms. For example, Severe Acute Respiratory Syndrome (SARS) virus appeared suddenly causing death and panic in many countries, and the Bird Flu virus posed repeated pandemic ducats.
Microbiology has become an increasingly important discipline, set to face new challenges. Exciting advances in diagnostic microbiology using sophisticated techniques can help in the rapid identification of new pathogens and serve to contain thern.This was shown by the identification of the new SA RS virus within wrecks by concerted mtdti-disciplinary international efforts. While such scientific progress is a boon, some of it can be potentially dangerous, as for instance in the recent case of chemical synthesis of a complete pathogenic poliovirus in the laboratory.