Legionella pneumophila is an emerging human pathogen that resides in natural environments as a parasite. It has been used as a probe for macrophage cellular function, which has led to new discoveries in cellular biology. Legionella has also become a model system for the study of innate as well as adaptive immunity. Information on Legionella continues to increase in the U.S. and abroad. Columbia University, for example, started the first Legionella Genome Project with a multi-million dollar grant from the NIH. In addition, The European Working Group for Legionella infections was formed in 1986. This volume brings together all of the latest research on this pathogen. Editor Herman Friedman is an acknowledged expert in the study of Legionella. He has assembled a team of distinguished and internationally recognized leaders in the field to contribute chapters in their respective areas of expertise.