Identifying the challenge -- The microbial world -- The beneficial aspects of microbes: the other side of the coin -- Bacteria -- Viruses and prions -- Bacterial genetics -- Concepts of microbial disease -- Epidemiology and cycle of microbial disease -- Bacterial diseases -- Viral and prion diseases -- Protozoans, helminthic, and fungal diseases -- The immune response -- Control of microbial diseases -- Partnerships in the control of infectious diseases -- Biological weapons -- Current plagues -- The unfinished agenda.