1976年7月,美国退伍军人协会在费城举行第58届年会。会议期间爆发了一场原因不明,但临床特征相同的流行病。与会人员连同家属共计4400余人,发病221人,死亡34人,病死率达15.4％。其主要特征为发热、头痛及严重的肺炎。尸检证实为广泛的肺炎及合并症。这场大规模流行的严重呼吸 July 1976, the United States Veterans Association held its 58th annual meeting in Philadelphia. An epidemic of unknown cause, but with the same clinical features, broke out during the meeting. Participants together with their families a total of more than 4400 people, the incidence of 221 people, 34 people died, the fatality rate of 15.4%. Its main features are fever, headache and severe pneumonia. Autopsy confirmed a wide range of pneumonia and comorbidities. This large-scale epidemic of severe breathing