[Recognition of influenza and other acute respiratory virus infections and their combinations by means of immunofluorescence].

The results of postmortem examinations performed in 237 fatal cases of influenza and other acute respiratory diseases are presented. In smears of organs and tissue culture cells infected with these materials and heart blood the immunofluorescent procedure detected influenza virus antigens in 67% of the cases, antigens of other respiratory viruses in 53% including 18-19% of mixed infections. Parallel immunofluorescent studies in living patients and isolation of influenza virus and adenoviruses increased per cent of influenza case confirmation to 82%, other respiratory infections to 63%. Mixed infection was recorded in 22-28%. Antigens of influenza and parainfluenza viruses were more frequently found in smears of bronchi and trachea, antigens of respiratory syncytial virus and adenovirus in lung smears. Adenovirus antigen was also found in lymphoid cells of smears of the spleen, bronchial lymph node, tonsils. In immunofluorescent examinations of tissue cultures infected with the heart blood, virus antigen was detected most frequently in influenza and adenovirus infection (24% and 26% of cases, respectively), less frequently in respiratory syncytial virus infection (11%) and parainfluenza (5%). Virus antigens were also demonstrated in tissue culture cells infected with specimens of the liver, spleen, bronchial lymph node, tonsils, brain. The immunofluorescent studies demonstrated long-term persistence of virus antigens in the body. In a portion of cases of laboratory confirmed mixed infection there were no clinical-morphological signs of two virus diseases. In these, one of the infections was latent or was due to a previously experienced disease.