The Etiology of Epidemic Poliomyelitis

After Landsteiner and Levaditi1and Flexner and Lewis2demonstrated independently that the causative agent of epidemic poliomyelitis could be passed through a bacterial filter, the disease was classed with those caused by a filterable, ultramicroscopic virus. The bacteria of ordinary size were no longer considered of etiologic importance, and when obtained were discarded as postmortem invaders or accidental contaminations. Wickman,3after reviewing the earlier experiments with streptococci, says, "The time has fully arrived when such investigations should be discarded from the literature of the disease." In 1913, Flexner and Noguchi4cultivated and demonstrated microscopically a small filterable micro-organism with which they produced poliomyelitis in monkeys. They note that "the cultural conditions are those that apply more particularly to the bacteria," but do not attempt definitely to classify the micro-organism. Rosenow5has shown by the use of special methods that the specific localizing power of bacteria