What happens in the body when a person becomes ill with influenza, malaria, or pneumonia? How do bacteria and viruses, fungi, and parasites interact at the molecular level with the body's cells? How do the pathogens act within the respective cells, where do they hide, and which cellular and molecular processes do they disrupt or paralyze? Jörg Hacker, Jürgen Heesemann, and their author team present in this specialized book the diverse and fascinating interactions between pathogenic microorganisms and their host cells. They describe the medically significant pathogens, the infections they cause, and the nonspecific as well as specific means by which the host can defend itself. They discuss in detail the factors of pathogenicity, protein secretion systems, and microbial surface variation.