Foot and Mouth disease (FMD) can be transmitted in a variety of ways, the most common being direct contact with an infected animal. Once infected, animals become "virus factories," capable of spreading high numbers of viral particles to other animals and into the environment. Infected swine in particular, can release millions of viral particles when they exhale. The virus can become airborne and can be breathed in by nearby susceptible animals. Persons who have been around infected animals also are capable of carrying the virus in their nasal passages for as long as 28 hours. While the disease is not considered to be a threat to humans, it is possible for a person to spread the virus to susceptible animals. The disease also can be spread when susceptible animals come into contact with feed, feeding utensils, vehicles, clothing, or holding facilities that have been contaminated with the virus. The FMD virus also can reside in the raw meat, animal products or milk from FMD-exposed or infected animals. The FMD outbreaks in South Africa were started after waste food containing raw meat scraps was collected from international ships and fed to swine.
A related link- Foot and Mouth Disease - FMD