Summary

We now know that human enteroviruses are a) cosmopolitan in distribution, being found in all parts of the world; b) seasonal and temperate, with occurrence limited principally to the summer months, and to tropical and subtropical areas and health resorts; c) democratic in practice, being causative agents of inescapable afflictions of man; d) commonplace in their selection of habitat, persisting under natural conditions as transient occupants of the orointestinal tract; e) hardy, making easy the problem of transfer to a new host by simple human association; f) productive only of misery and ill health, as evidenced each year by summer grippe and diarrhea, pleurodynia, paralysis, aseptic meningitis and myocarditis; and, finally, g) eagerly ambitious as shown by progressive displacement of the polioviruses as causative agents of viral disease of the central nervous system.