This transmission electron microscopic (TEM) image revealed some of the ultrastructural morphology exhibited by a grouping of Enterovirus 70 virions.
Enteroviruses are small viruses that are made of ribonucleic acid (RNA) and protein. This group includes the polioviruses, coxsackieviruses, echoviruses, and other enteroviruses. In addition to the three different polioviruses, there are over 60 types of non-polio enteroviruses that can cause disease in humans.
Non-polio enteroviruses are very common. They are second only to the "common cold" viruses, the rhinoviruses, as the most common viral infectious agents in humans. The enteroviruses cause an estimated 10-15 million or more symptomatic infections a year in the United States. All three types of polioviruses have been eliminated from the Western Hemisphere, as well as Western Pacific and European regions, by the widespread use of vaccines.