Experimental respiratory infection in monkeys produced by influenza a virus and Staphylococcus aureus

Summary

Inoculation of influenza virus into the upper respiratory tract of monkeys may result in the development of necrosis and desquamation of the epithelium, peribronchiolar and interalveolar oedema, and limited foci of pneumonitis. Staphylococcus aureus, when inoculated by the same route, may produce a slight bronchiolitis, without epithelial necrosis, and limited foci of bronchopneumonia, the cellular infiltration being leucocytic in character. Simultaneous inoculation of both influenza virus and staphylococci produces bronchiolitis with epithelial necrosis, and bronchopneumonia. Necrosis of epithelium, which is the main lesion produced by the influenza virus, may occur either through the entire respiratory tract, or may be limited to the bronchioles. As a matter of fact, epithelial lesions in the entire respiratory tract were common in monkeys inoculated with both virus and staphylococci, whereas they were mostly limited to the bronchioles in monkeys inoculated with influenza virus only. This might suggest, that the staphylococcal infection has some unfavourable influence on the resistance of the epithelium to infection with influenza virus. On the other hand, the penetration of staphylococci is apparently facilitated by the epithelial lesions and the pulmonary oedema produced by the influenza virus.