VIRUSES, MYCOPLASMA PNEUMONIAE AND BACTERIA ASSOCIATED WITH LOWER RESPIRATORY TRACT DISEASE AMONG INFANTS

Mufson, M. A. (Hektoen Institute for Medical Research, Chicago, III. 60612), H. E. Krause, H. E. Mocega and F. W. Dawson. Viruses, Mycoplasma pneumoniae and bacteria associated with lower respiratory tract disease among infants. Amer. J.Epid., 1970, 97: 192–202.—Among 746 infants requiring hospitalization for pneumonia, bronchiolitis, laryngo-tracheo-bronchitis or bronchitis during the period January 1, 1967 to June 30, 1968, viruses were associated with approximately one-half of these illnesses. Virus infections were detected by isolation of an accepted etiologic agent during the acute illness with or without demonstration of homologous antibody titer rises or only by the detection of significant rises in antibody titers. Respiratory syncytial virus, parainfluenza viruses types 1, 2 and 3, and influenza A virus accounted for most of the virus infections. No respiratory syncytial virus or influenza A virus and few parainfluenza virus infections were identified among 54 infants without respiratory disease. Few ill infants had adenovirus, picomavirus or herpesvirus infections; these infections occurred with about the same frequency among infants with or without respiratory tract disease. Sorologic evidence of M. pneumoniae infection was obtained in 2% of infants with lower respiratory tract disease and bacteremias in 4.4%. Combined infections with virus, M. pneumoniae and pathogenic bacteria occurred in 7.2% of pneumonias and 4.9% of bronchiolitis illnesses. Overall, an etiologic organism was identified in nearly 60% of pneumonia and bronchiolitis illnesses.