Aphthovirus

Aphthovirus is a genus of viruses in the family Picornaviridae. It comprises the Foot-and-mouth disease virus (FMDV) as the type species; FMDV is the only species currently recognized in the genus. The viruses are small, non-enveloped, icosahedral particles about 25–30 nm in diameter. Their genome is a positive-sense single-stranded RNA of about 8.4 kilobases, organized as a single large open reading frame that encodes a polyprotein; processing yields structural proteins VP1–VP4 and non-structural replication proteins. The genome contains a 5' untranslated region with an internal ribosome entry site and a 3' poly(A) tail.

Natural hosts are domestic and wild cloven-hoofed mammals, including cattle, pigs, sheep, goats, and some wildlife; accidental infections of other species are rare.

FMDV exists as several serotypes (O, A, C, Asia1, SAT1, SAT2, SAT3). Immunity is serotype-specific, and infection or vaccination against one serotype does not confer protection against others.

Diagnosis relies on virus detection by RT-PCR or virus isolation from vesicular fluid, saliva, or tissue, as well as serology. Control relies on vaccination with inactivated vaccines, movement controls, surveillance, and, when feasible, stamping-out or culling policies. Outbreaks have substantial economic impact and are subject to strict reporting and containment measures in many countries.