Sera of 947 members of 169 southern Louisiana households and of 995 Peruvian Indians from the Andean highlands were examined for the presence of encephalomyocarditis (EMC) virus neutralizing antibodies. Of the sera from Louisiana 3.5% showed antibodies; of those from Peru, 9.6%. In both populations it was found that boys and girls had equal prevalence rates but that adult females had higher rates than did adult males. The data suggest an association between very poor hygienic household conditions and probability of infection. No familial pattern in the occurrence of antibodies was found. The possibility that man becomes infected by the contamination of skin wounds with infective rodent excreta was mentioned.
Present address: Trinidad Regional Virus Laboratory, P. O. Box 164, Port-of-Spain, Trinidad.