Walsh & Hoyt: Picornaviridae

The picornaviruses are named for their small size (from the Latin pico, meaning ""very small"") and their nucleic acid (RNA). The family Picornaviridae contains four genera. One, Aphthovirus, contains viruses that do not infect humans but produce a condition called foot-and-mouth disease in various animals, such as cattle, swine, sheep, and goats. A second genus, Cardiovirus, contains viruses that are primarily pathogenic for rodents, monkeys, and various domestic livestock. These viruses can produce an encephalomyocarditis in mice and, rarely, cause a mild febrile illness in humans that occasionally includes minor neurologic manifestations. Only two genera in the family Picornaviridae contain viruses that commonly infect humans: (a) the genus Enterovirus, which has over 65 species, and (b) the genus Rhinovirus, which includes over 100 species. These two genera can be separated on the basis of clinical, epidemiologic, and biophysical properties. The genus Enterovirus contains several species of viruses that produce diseases of neuro-ophthalmologic significance, whereas rhinoviruses produce little, if any, neurologic or ocular disease.