1950 Louisville outbreak

In October, 1950, 37 student nurses out of 161 came down with epidemic neuromyasthenia. 20 required hospitalization.

Findings
"Attempts to isolate an infectious agent failed in the 33 patients and eight asymptomatic student-nurse contacts whose feces were tested in suckling and adult mice and in rhesus monkeys. Repeated attempts and "blind passages" were negative. The paired serum specimens of the 33 patients and eight contacts were subjected with negative results to complement-fixation tests against the Coxsackie viruses known in 1951."

Prognosis
The duration of illness ranged from one week to as long as three months in one patient.