NEW YORK ACADEMY OF MEDICINE, SECTION OF PEDIATRICS

Abstract

Studies in Influenza. Dr. Perrin H. Long, M.D. During the past five years certain studies with regard to the etiology of influenza have been carried out in Baltimore under the auspices of the John J. Abel Fund for Research on the Common Cold. In this period three epidemics of influenza have been investigated. Extensive observations on the incidence of Haemophilus influenzae, the beta hemolytic streptococci, Diplococcus pneumoniae and the anaerobic, gram-negative, filter-passing flora of the rhinopharynx have been made in healthy persons and in persons suffering from disease of the respiratory tract. In addition, the hypothesis that the incitant of influenza may be a filtrable virus has been tested. It has been found that the incidence of H. influenzae in influenzal years is not significantly higher than in noninfluenzal years, nor is the incidence of this organism in persons with influenza high enough to be of etiologic significance when compared with the findings in persons not suffering from the disease. However, there is some evidence to show that during a noninfluenzal year persons who are infected with H. influenzae during infections of the respiratory tract have a more severe type of disease than do those who are found to be free from infection with H. influenzae. In an influenzal year this difference between carriers and noncarriers does not exist. The beta hemolytic streptococcus and D. pneumoniae have been found to play the role of secondary invaders in influenza. Although extensive studies have been undertaken to determine the incidence and the role of the gram-negative, filter-passing, anaerobic organisms of the rhinopharynx in health and in disease of the respiratory tract, no convincing evidence of their importance in the production of disease has been obtained. Bacterium pneumosintes has not been isolated, and therefore its relationship to influenza has been neither proved nor disproved. It is felt that a further accumulation of experi¬ mental evidence is necessary before the relationship of these minute anaerobic organ¬ isms to respiratory disease' is settled. Attempts have been made during the past three years to transfer influenza to chimpanzees by inoculating them with filtered rhinopharyngeal washings from persons ill with influenza. In the course of these attempts, disorders characterized by fever, prostration and leukopenia or a normal white blood cell count were transmitted to four chimpanzees by rhinopharyngeal inoculation with bacteria-free filtrates from persons ill with human influenza, and a similar condition was produced in a fifth ape during a nonepidemic period. The difficulty of interpreting with complete satisfaction the observations made on the apes is obvious, and the observed facts are therefore presented in the knowledge that they conform with those pre¬ viously reported in man by other investigators.