Interstitial Pneumonitis Induced by Experimental Infection with Hemophilus Influenzae

In a recent study of acute bronchiolitis in infants, Hemophilus influenzae was isolated from nasopharyngeal cultures of 48 of 73 infants. Agglutination against type-specific antigens of H. influenzae was detected in convalescent serum samples from 59 of these infants. No cytopathogenic viral agents could be demonstrated in the nasopharyngeal washings of 46. No hemabsorption viruses could be detected in any of the 24 tested. No significant complement-fixation titer rise could be demonstrated with the following viral antigens: adenovirus, CA, HA-1, HA-2, influenza virus A, B, C, D, or swine. One patient had a rising titer to influenza A. In order to study further the possible relationship of H. influenzae to the pathogenesis of clinical bronchiolitis, experiments were undertaken to try to reproduce the characteristic pathological lesions in newly born mice by the intranasal inoculation of strains of bacteria recently isolated from acutely ill patients. H. influenzae, Type b, has long