A Clinical Report on Cases of Primary Atypical Pneumonia Caused by a New Virus.


During the 10 years which have passed since the disease now designated as primary atypical pneumonia began to take form as a definite clinical entity, considerable progress has been made in studies of its clinical and epidemiological aspects (1). Progress in etiological studies, however, has been comparatively slow. The isolation of a number of infectious agents from single patients or small groups of patients (2 to 10) has made it clear that the clinical syndrome under discussion is of diverse etiology and that the human organism, like a variety of experimental animals, may show a somewhat similar clinical and pathological response when any one of a number of unrelated nonbacterial infectious agents is introduced into the lower respiratory tract. At the same time, there is no convincing evidence that the great majority of cases reported have been due to any of the viruses or rickettsiae isolated up to the present. The discovery that an infectious agent in the sputum or lungs of patients with primary atypical pneumonia produced a pneumonic infiltration when inoculated intranasally into cotton rats (11) opened a new line of approach. Investigation was further facilitated by the subsequent demonstration that this agent, presumably a virus, multiplied when introduced from human material into the amniotic sac of the chick embryo and that suspensions of infected chick embryo tissues produced a similar pneumonic response in cotton rats and hamsters. The properties of this virus, which is apparently

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@article{Meiklejohn1945ACR, title={A Clinical Report on Cases of Primary Atypical Pneumonia Caused by a New Virus.}, author={Gordon Meiklejohn and M D Eaton and William van Herick}, journal={The Journal of clinical investigation}, year={1945}, volume={24 2}, pages={241-50} }