Even though it has a low fatality rate, HMD is considered the world's most important animal disease. HMD is present in Africa, Asia, South America, and Europe. In 1997, more than 4 million pigs died or were slaughtered within two months during a devastating epidemic in Taipei, China. HMD affects all cloven-footed animals. Horses are not susceptible to the disease.
Humans are susceptible to a related enterovirus that causes hand, foot and mouth disease.
The virus that causes HMD is easily and rapidly transmitted through air, infected meat and milk products, clothing, or other means by which the agent can be carried to the next host. It is estimated that sufficient virus to initiate an infection can be windborne as far as 150 miles. Pigs are the most potent excretors of airborne virus, and cattle the most susceptible to airborne infections. Animals that have recovered from the disease can commonly continue to be carriers of the virus and remain infectious for as long as 6 months. The virus may persist for over one year on infected premises, for 12 weeks on clothing and feed, and for up to month on hair.