An Unidentified, Filtrable Agent Isolated From the Feces of Children With Paralysis

Abstract

Epidemics of poliomyelitis in upstate New York were studied for evidence of mouse-adaptable viruses. An agent was isolated from the acute-phase fecal specimens of 2 children which induced paralysis in suckling mice and hamsters. The paralysis was associated with skeletal muscle lesions, involving severe widespread degeneration of the muscle. The cells lose their striations and become acidophilic and fragmented. Proliferation of young muscle cells occurs, a and,with endothelial cell phagocytosis, gives the lesions a very cellular appearance. Smooth muscle and myocardium are spared. There were no lesions in the central nervous system or in the large peripheral nerves. The agent fails to propagate except in suckling mice and hamsters. It was not neutralized by adult normal mouse serum or normal rabbit serum. Pooled human serum, human coned, globulin, and,-to some extent, normal monkey serum had a neutralizing effect. The agent may be capable of infecting man, but that it induces paralysis in man is unproven.