Chlamydia pneumoniae is a bacteria that is most commonly known for causing colds and pneumonia. However, researchers have recently found a link between C. pneumoniae and atherosclerosis, a clogging of the arteries that causes heart attack and stroke. In addition, ongoing research is showing that certain strains may play a role in asthma, multiple sclerosis, Alzheimer's disease, and arthritis. This volume, part of the Infectious Agents and Pathogenesis series, is a complete portrait of C. pneumoniae and what is currently known about it.