| legionnaires' disease in pneumonia patients in iowa. a retrospective seroepidemiologic study, 1972-1977. | the frequency of legionnaires' disease among 586 cases of pneumonia that occurred in iowa between fiscal years 1972 and 1977 was studied retrospectively on the basis of paired sera. the frequency of confirmed legionnaires' disease was 4.1% and of presumptive legionnaires' disease was 11.4%. infections with the legionnaires' disease (ld) bacterium were most frequent in the summer. of the 22% of pneumonias for which a cause could be defined, legionnaires' disease was third in frequency behind myco ... | 1979 | 434644 |