Environmental mycobacteria can be found in diverse environments around the world and most appear to exhibit a saprophytic lifestyle. However, some have the ability to infect animals, birds and humans, and have evolved mechanisms by which they can invade and grow within host cells: the pathogenic environmental mycobacteria (PEM). Although the diseases caused by these organisms have been known for many years, it is only recently that the potential significance of PEM as a waterborne pathogen has been appreciated. Pathogenic Mycobacteria in Water describes the current knowledge of the distribution of PEM in water and other parts of the environment. The routes of transmission that lead to human infection are discussed and there is a detailed analysis of the most significant disease symptoms that can follow infection. Many species of PEM are difficult to isolate in culture and so detection and identification rely upon the use modern techniques such as those based on selective nucleic acid amplification (PCR). The classical and modern methods of analysis are described. The book concludes with a discussion of the issues surrounding the control of PEM in drinking water and the assessment and management of risks.