Municipal control of epidemics of infantile paralysis is a most difficult problem. In order to obtain any results we must utilize our knowledge to the utmost; measures should be comprehensive, definite and rigid. Infantile paralysis is produced by a minute infectious agent which cannot be isolated, cultivated or identified by the usual bacteriologic method. The virus is present in the secretions of the nose, throat and intestines of the sick, and has been found in the noses and throats of healthy contacts, who may remain healthy carriers.
The virus can be carried on the surface and in the intestines of the common house fly. It is probable that other insects, vermin and domestic animals may similarly carry and disseminate the virus.
Accurate data have not been obtained on the duration of living virus in the nose and throat of the sick or in healthy contacts. In monkeys the virus has