Identification of Coxsackie and ECHO Virus Isolates with Fluorescent Antibody

A direct fluorescent antibody staining method for laboratory identification of 3 Coxsackie and 3 ECHO viruses isolated from stool specimens is reported. In the method, monkey kidney tissue cultures inoculated with stool suspensions are stained when they show early cytopathic effect. Seventy stools were studied as unknowns by the fluorescent antibody method. Fifty-five of these had previously been found to contain 1 of the 6 viruses by routine procedures involving neutralization tests. Fifty-one were correctly identified by the fluorescent antibody method. Of the 4 failures, 3 were found negative and 1 was incorrectly typed. Fifteen specimens shown not to contain any of the 6 viruses by the routine method were negative by fluorescent antibody. The reasons for the 4 failures with fluorescent antibody were investigated and modifications introduced into the method that should make it as sensitive and specific as the procedure using neutralization tests. Identification of the viruses was made much more rapidly with fluorescent antibody.