A picornavirus is a virus belonging to the family Picornaviridae. Picornaviridae is a family of viruses in the order Picornavirales. Vertebrates, including humans, serve as natural hosts. There are currently 50 species in this family, divided among 29 genera. Diseases associated with this family include: paralysis (non-polio and polio-type), summer cold, meningitis, diarrhea caused by Enteroviruses; foot-and-mouth disease (bovine) caused by Aphthoviruses; myocarditis caused by Cardioviruses; common cold caused by Rhinoviruses; and hepatitis caused by Hepatoviruses. The name is derived from pico, meaning "small," and RNA, referring to the ribonucleic acid genome. Thus, "pico-rna-virus" literally means "small RNA virus."