Infectious disease is the single biggest cause of death worldwide. New infectious agents,such as the Severe Acute Respiratory Syndrome coronavirus and new strains of influenza continually emerge and require new investigations to understand pathogen biology and pathogenesis in the host. Witness the Influenza A pandemic. Concerns about new viruses and their impact on health and the economy are also increasing. Current alerts sent out by the Ministry of Health (about the novel coronavirus and the Avian influenza A virus) are but cases in point. These likely reflect advances in science, which have allowed novel pathogens to be identified.