The positive detection of the virus of poliomyelitis in the nasal secretions of 2 children, 16 and 13 days after the onset of the disease, is described. 7 animals which had been inoculated with other concentrates became ill with symptoms and temperature elevations suggestive of poliomyelitis, from 1 to 3 weeks following inoculation, but without definite paralysis. In 2 of these animals which were sacrificed, the histologic findings were compatible with the diagnosis of poliomyelitis but were not typical. Of the serums of the 5 remaining animals 4 failed to neutralize stock virus, whereas the serum of the fifth neutralized the virus on two different occasions. This serum was obtained from a monkey that had been inoculated with concentrated nasal secretions of a child 43 days after the onset of illness.
It is suggested that the present quarantine period of 3 weeks is compatible with the available data. It is further suggested that the methods of procedure described may be useful in similar investigations.