Clinical Epidemiology

well as serving to introduce the general reader to the basic life-processes of viruses, the most elementary of all living things. The arrangement of the book represents a trend away from classification by disease and towards a classification by the nature of the causative agent. Infections due to B-virus, the simian member of the herpes group, are now discussed with herpes simplex infections instead of with viral encephalitides. The chapters on dengue and yellow fever are placed near those on the other anthropod-borne diseases. This arrangement facilitates discussion of epidemiology and etiology and detracts little from the book's usefulness for clinical reference. The new chapters on the ECHO and adenoviruses will doubtless prove useful to anyone concerned with infectious diseases. These newly recognized viruses are responsible for a variety of illnesses which usually are of a minor nature. The extensive diagnostic criteria which are now available are not sufficiently refined to allow identification of most individual cases solely on clinical grounds, but these agents frequently occur in epidemic form, often with striking intensity. Under epidemic conditions clinical diagnosis can become much more accurate and laboratory tests more practical. Perhaps the publication of these diagnostic criteria in this generally available form will mark the beginning of the end of that favorite equivo-cation, "It's a virus infection." The preface describes the third edition as "an entirely new book." This is true of many chapters, and others represent thorough revisions. However , a few chapters are almost the same as in the first edition with new data only tacked on the end of subsections rather than integrated into the body of the text. The contributors have been chosen "because of their eminence and experience" rather than because of their current familiarity with these fast-moving subjects. In a few cases they seem to have lost contact with the import of recent developments. Several other books on viruses are now available but this one remains the most comprehensive and best balanced reference in medical virology. It is highly recommended to anyone concerned with this field. This presentation of the subject of clinical epidemiology is appropriately divided into three components which are concerned respectively with the history, principles, and applications of the subject. The material is introduced and discussed by the author in a concise manner and as an orientation towards the goals and activities of the clinical epidemiologist. Part I provides a brief discussion and …