Foy H M, Cooney M K, Allan I, Kenny G E
JAMA. 1979 Jan 19;241(3):253-8.
Influenza A epidemics were associated with a doubling to tripling of pneumonia rates among adult members of a prepaid medical care group studied between 1963 and 1975. Rates of influenza A associated with pneumonia increased with age. Influenza B epidemics did not have a similar effect. Overall pneumonia rates were highest in children younger than 5 years, but in this age group, other respiratory viruses dominated as causative agents. Influenza A and B epidemics were not always synchronized with those reported for the United States, and rates of influenza A infection varied between urban and suburban areas in sequential epidemics. In 1974, a year practically free from influenza A, a prolonged Mycoplasma pneumoniae epidemic kept rates of pneumonia high, especially during the summer.
在1963年至1975年期间对一个预付医疗保健组的成年成员进行的研究中，甲型流感流行与肺炎发病率翻倍至三倍有关。与肺炎相关的甲型流感发病率随年龄增长而增加。乙型流感流行没有类似的影响。总体肺炎发病率在5岁以下儿童中最高，但在这个年龄组中，其他呼吸道病毒是主要病原体。甲型和乙型流感流行并不总是与美国报告的流行同步，在连续的流行中，甲型流感感染率在城市和郊区有所不同。1974年，实际上没有甲型流感，肺炎支原体长时间流行使肺炎发病率居高不下，尤其是在夏季。
