The Effect of Human Strains of Hemophilus influenzae on Influenza Virus Infections of Swine

Abstract

Both stock and freshly isolated human meningeal Type b and respiratory "rough" strains of H. influenzae were used in combination with PR8 human and V 15 swine influenza virus for infecting a total of 29 young swine. No significant synergistic action was observed between the human hemophilus strains and either of the influenza virus strains tested. The histopathologic picture was that of the "filtrate" disease in most cases. In only 2 instances was it possible to isolate a human strain of H. influenzae from the swine respiratory tract after an interval of 5 days. This suggests another biologic difference between human and swine strains of H. influenzae.