Experimental infections with some pneumotropic viruses in the mouse. Note II. Virological and pathomorphological aspects of experimental associated infections with parainfluenza virus, adenovirus and respiratory syncytial virus in the mouse.

Associated infections with long-strain parainfluenza virus type 3, adenovirus type 3 and respiratory syncytial virus were experimentally induced in white mice. They were pointed out by the appearance of homologous serum antibodies, positive IF reactions in the pulmonary tissue, and histological, histochemical and histoenzymatic lesions, which were more severe than those of controls infected with single virus of those mentioned above, since they involved wider areas and had a high frequency. The pathomorphological changes made up an inflammatory, exudative, alternative and predominantly infiltrative lymphohistiocytic picture, mainly pulmonary (diffuse interstitial bronchopneumonia, sometimes with a peribronchovascular location, of a cuff-like aspect), hepatic, renal and cardiac, but dystrophic processes were also present--hyalinosis of tunica media in the lung, hepatocyte cytoplasm vacuolizations on areas of various sizes of lobuli--, especially in associated infections with parainfluenza virus type 3 and adenovirus type 3. Megakaryocytic hyperplasia in the spleen, present in all the experimental models, was also described. Generally, the modified structural aspects made up and pointed out a complex pathological process.