ümbriseta 20‑tahulised üheahelalised RNA‑viirused, nt. polioviirus, Coxsackie viirus, A‑hepatiidi viirus, kardioviirus, any of a family (Picornaviridae) of small single-stranded RNA viruses that include the causative agents of encephalomyocarditis, hepatitis A, polio, foot-and-mouth disease, and hand, foot and mouth di