The Epidemiology of Primary Atypical Pneumonia

Abstract
Introduction and Review of the Literature During the past five years, with the development of newer techniques in virology, many new clinical entities have been established among those maladies commonly known as the "respiratory infections." In many instances the etiologic agents causing these disorders have been isolated and identified, while others remain to be found. In this paper we shall review the literature regarding the existing knowledge of the viral respiratory infections. Studies then will be presented concerning primary atypical pneumonia. Future publications will deal with the work now in progress with other diseases which are classified in this group. It is the purpose of the present communication to contrast the epidemic form of primary atypical pneumonia with the sporadic and subclinical types by presenting data which have been accumulated18 from a study of this disease since 1951. The fact that influenza A (Asian strain) is appearing at this