Foot-and-mouth Disease

Foot-and-mouth disease, FMD, is sometimes fatal and is highly contagious for cloven-hoofed animals. Along with hooved animals hedgehogs and elephants are susceptible to the disease as well. Llama and alpaca can develop mild symptoms but are resistant to the disease and don’t pass it to other species. Mice, rats, and chickens have been infected artificially in a lab but it is not believed they can contract the disease under natural conditions.

Humans can spread the disease by carrying the germs on their clothes and body. Animals can also spread it even when not susceptible. This happened in 1952 when dogs carried bones of dead animals off causing an outbreak. The virus is highly variable and transmissible, but, rarely affects humans. Out of the seven serotypes O is the most common and they all show some regionality.

Friedrich Loeffler first found FMD to be viral in 1897 when he passed the blood of an infected animal through a chamberland filter and found the fluid could still cause the disease in healthy animals. FMD is worldwide and presents an international concern. Asia, Africa, and parts of South America were declared endemic areas as of 1996. Chile was disease from as of 2007 and Uruguay and Argentina have had no outbreaks since 2001. New Zealand has never had a case and North America and Australia have been disease free for years.

In 2001 Britain had an outbreak that resulted in the slaughter of many animals. The republic of Ireland avoided a disastrous epizootic through strict government policies and disinfecting all persons leaving farms.

Foot-and-mouth disease has an incubation period between 2 and 12 days. The disease causes high fever that declines after two to three days. Blisters may form inside the mouth and also on the feet which when ruptured can cause lameness. Adult animals may suffer weight loss. Most animals recover from FMD although it can lead to myocarditis and death especially in newborns. Some animals are only carriers and aren’t symptomatic.

Transmission can be transmitted through close animal contact, fomites, inanimate objects, and motor vehicles. Clothes, standing water, and uncooked food scraps can also harbor the virus. FMDV, an aphthovirus of the viral family, is the cause of Foot-and-Mouth. These viruses, when in contact with a host cell, bind to a receptor site and trigger a folding-in of the cell membrane. Once the virus is inside the host cell the protein coat dissolves.

Although it rarely infects humans there are two cases of Children dying, in 1884, in England from infected milk. The lack of human infection makes FMD a much greater threat to the agriculture industry than to human health. This can cause money loss to farmers and production to go down. FMD continually evolves and mutates thus causing it to be hard to vaccinate. Between the serotypes there is no cross protection. On top of that vaccination only lasts from a few months to years.

The World Organization for Animal Health recognizes the state of FMD to be one of three: FMD present with or without vaccination, FMD-free with vaccination, and FMD-free without vaccination.