Prevalence of infection with nonpolio enteroviruses among healthy children from a children's home and in a summer camp.
The sera obtained at 6 samplings between June 1981 and May 1982 from 30 children in a children's home were tested for neutralizing antibodies to coxsackieviruses B1 through B5, echovirus serotypes 1, 2, 4, 5, 6, 7, 11, 19, 24, 30 and to enterovirus type 71. Another group of examined children comprised 19 individuals from the children's home and 63 children from families who enrolled as participants of a summer camp recreation. Samples of their sera were obtained at the beginning and the end of camping in July and August of 1981. Virus isolations were attempted in 150 stool specimens collected at various times during the observation period, and in specimens of summer camp swimming pool water collected 2-3 times a week. Overall, 10 strains of enterovirus (CB2, E2, E19, E24) were isolated from stool, but none from swimming pool water. Serologically, fourfold or greater increases in titre of antibody to at least one of the enteroviruses tested were observed 17 children, of whom 4 children showed antibody titre increases simultaneously to two enterovirus serotypes. None of the present viruses showed a tendency to mass spread. Some of the examined children showed the presence of serum antibody to enterovirus before its isolation from stool. Eight of the ten children positive for enterovirus in stool did not react by significant increases in titre of antibodies. Enteroviruses were more frequently isolated in children's home in autumn than in summer camp. Clinically, all virologically or serologically demonstrated enteroviral infections were asymptomatic. Children's home children had a significantly higher prevalence of antibodies to enteroviruses than children from families. Presumably, asymptomatic infections with nonpolio enteroviruses among children appear to be far more frequent than the results of neutralization tests in the study indicated. Moreover, enteroviruses may apparently circulate among humans who are seropositive for the respective enterovirus serotype.