Definition: A family of very small (20–30 nm) ether-resistant, nonenveloped viruses having a core of positive sense single-stranded infectious RNA enclosed in a capsid of icosahedral symmetry with 60 capsomeres. Numerous species (including the polioviruses, coxsackieviruses, and echoviruses) are included in the family. There are five accepted genera: Enterovirus, Rhinovirus, Hepatovirus, Cardiovirus, and Aphthovirus.
[It. piccolo, very small, + RNA + -viridae]