Intestinal Viral Flora of Healthy Children Demonstrable by Monkey Kidney Tissue Culture

Abstract

Rectal swabs from 3337 healthy children in the U. S. and Mexico were cultured in cynomolgus monkey-kidney-tissue cultures and 365 cytopathogenic agents were recovered[long dash]31 from 1566 children aged 1 to 17 years tested in Cincinnati during July-Aug., 1953 and 334 from 1771 children aged 1 to 4 years in Mexico City and Veracruz during June, 1954. The 31 Cincinnati agents consisted of 5 polio viruses, one Coxsackie (B4), and 25 new viruses, comprising 5 distinct antigenic types. The 334 Mexican strains included 73 polio viruses and 66 strains which proved to belong to 4 of the 5 newly identified Cincinnati HE prototype viruses. Preliminary tests with other pools of Coxsackie and "orphan" (ECHO) virus antisera suggest that at least 85% of the remaining 195 Mexican strains constitute a new group of agents requiring further serologic classification. Among the 1 to 4-year old healthy children the carrier rate for polio viruses was 0.6% in Cincinnati, 3.4% in Mexico City and 8.2% in Veracruz, while the carrier rate for the other cytopathogenic viruses was 5.2% in Cincinnati, 15.6% in Mexico City and 10% in Veracruz. These new cytopathogenic agents in the human enteric tract are not the viral counterpart of the normal bacterial flora because they occur most frequently during the early years of life and at least in the U.S. very rarely after the 10th year of life. The increasing incidence of antibody with increasing age suggests that these viruses cause transitory infections in many human beings. The clinical manifestations, if any, of these infections remain to be determined by future studies.