Test code links throughout this Guide refer to the corresponding test in the User's Guide. They have worldwide distribution. The primary route of infection is fecal- oral, but may rarely be spread by respiratory droplets. As with the other enterovirus syndromes, viral isolation is the preferred method of laboratory diagnosis.
Serology is of limited value.
A fourfold or greater rise in titers in sera bracketing the illness is much more convincing proof of disease association. In Manual of clinical laboratory immunology , 4th ed. NR Rose, et al, eds. In Manual of clinical microbiology , 7th ed. P Murray, et al, eds.