Neutralization microtest with human coxsackievirus and echovirus serotypes

Sets of 600 single sera from healthy individuals of various age and 458 paired sera from patients treated for diseases of various etiology were examined using a neutralization microtest technique employing prototype collection strains CA9, CB1-CB5, E1-E9, E11-E14, E17, E19, E24 and E26. Totally, 34,862 monotype neutralization tests were carried out in this study. In the set of single serum samples the lowest proportion of sera reacting with any of the enterovirus serotypes used was encountered in the group of youngest children up to the age of 2 years. This group of children showed also the highest proportion of sera free of type-specific antibody. Taken together, these sera reacted most frequently with serotypes CA9 and CB4. In the set of paired sera significant rises in antibody titre to one enterovirus serotype were recorded in 105 instances, in association with simultaneous nonsignificant rises against one or several other serotypes in 64 instances. In additional 12 paired sera there was evidenced a significant rise of antibody titre to more than one serotypes, combined in 8 of these with simultaneous nonsignificant rises to further serotypes. This neutralization microtest technique with a set of enterovirus serotypes is believed to represent a servicable diagnostic tool in determining the cause of enteroviral infection, in spite of the estimated 10% failure to establish the exact serotype responsible. The results yielded by the serologic examination of single serum samples are not considered as reflecting the actual seroconversion rates in the general population.