The purpose of the book is to present up-to-date summary of the newly detected viruses and to guide clinicians and microbiologists to the relevant topics and help to make readers aware of the increasing problem of respiratory viruses. Although much is published on new respiratory viruses and its acceptance in having a daily impact in respiratory medicine, most practitioners, as well as microbiologists, neglect those pathogens or are even unaware of their existence. This may, in part, be due to the fact that most of them have only limited access to scientific journals (mainly the practitioners), whereas books are more available. An up-to-date summary is highly necessary and this book presents a short sketch for every pathogen, giving the most relevant information on each one which is followed by detailed reviews.