This was thought to be a disease affecting both the heart muscle and the endocardium and it was given various names such as: idiopathic hypertrophy of the heart, endocardial sclerosis, cardiac enlargement of unknown cause, etc. Some of these hearts also had overt congenital anomalies, especially aortic stenosis and coarctation of the aorta.The term "endocardial fibroelastosis" was introduced by Weinberg and Himmelfarb in 1943. In their pathology laboratory they noted that usually the endocardium was pearly white or opaque instead of normally thin and transparent and microscopically showed a systematic layering of collagenous and elastic fibers. They felt their new term was more adequately descriptive, and, indeed it was quickly and widely adopted. Clinicians began applying it to any infant with a dilated, failing heart, in spite of the fact that the only way to definitively establish the presence of EFE was to see it at autopsy. EFE had quickly become the name of a disease, and it continues to be used by many physicians in this way, though many patients with identical symptoms do not have the endocardial reaction of EFE.In the latter decades of the twentieth century, new discoveries and new thinking about heart muscle disease gave rise to the term "cardiomyopathy". Many of the cases of infantile cardiac failure were accordingly called "primary cardiomyopathy" as well as "primary EFE", while those with identifiable congenital anomalies stressing the heart were called "secondary EFE".
Seven of 61 cases with EVD68 detected and eight long‐term follow‐ups had full recovery; two deaths were described in severely immunocompromised people (one with EVD68 and one with both EVD68 and coxsackie A16 detected).Six of 10 children in Denver were sent home for outpatient treatment. Some of the children with mild and moderate cases have recovered partially from temporary limb weakness but still have permanent weakness,  whereas those with more severe cases have not recovered as much. Intensive physical therapy and occupational therapy may be beneficial for recovery. Epidemiology
A seasonal pattern is seen in outbreaks, with a marked increase in cases reported in the late summer and early fall.The CDC has determined and submitted to GenBank complete or nearly complete genomic sequences for three known strains of the virus, which are "genetically related to strains of EV-D68 virus that were detected in previous years in the United States, Europe, and Asia. "While rates of paralytic symptoms appear to be correlated with the number of respiratory infections, in initial anecdotal reports, the cases are not clustered within a family or school, suggesting that the paralysis per se is not directly contagious, but arises as a very rare complication of the common respiratory infection.Cases of similar illnesses have been reported in Canada, Northern Europe, and Japan. Over 90% of reported cases are in children.