Characteristics of Poliomyelitis and Other Enteric Viruses Recovered in Tissue Culture from Healthy American Children. ∗

Abstract

Summary

Rectal swabs from 1566 healthy American children who had no contact with clinically recognized cases of poliomyelitis were tested in monkey kidney tissue cultures. Among the 31 cytopathogenic agents which were recovered, 5 were poliomyelitis virus (three Type 2 and two Type 3), one was a group B Coxsackievirus, and 25 belonged to a hitherto unidentified group of enteric viruses. This new group of human enteric or HE viruses is antigenically unrelated to the so-called “orphan viruses” recovered in tissue culture by Melnick and by Steigman et al., from the stools of patients with suspected nonparalytic poliomyelitis. 22 of (these 25 new viruses belong to 3 distinct serologic types (8 were Type 1, 11 Type 2 and 3 Type 3). The HE 1, HE 3 and the 3 unclassified strains were neutralized by human gamma globulin while the HE 2 virus was not. The HE 1 and HE 2 strains produced neither paralysis nor any significant lesions after intraspinal injection in cynomolgus monkeys. The 5 poliomyelitis viruses were all intracerebrally aviru-lent spinal variants for cynomolgus monkeys. The Type 2 poliomyelitis viruses were pathogenic for mice by the spinal but not the intracerebral routes, while the Type 3 viruses were a virulent for mice by both routes. Among children under 10 years of age who came to clinics from families of lower income groups, poliomyelitis virus was recovered from about 1% and the new enteric viruses from about 6%.