Foot-and-mouth disease

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Not to be confused with hand, foot and mouth disease.
Foot-and-mouth disease
Foot and mouth disease in mouth.jpg
Ruptured oral blister in diseased cow.
Classification and external resources
ICD-10 B08.8 (ILDS B08.820)
ICD-9 078.4
DiseasesDB 31707
MeSH D005536

Foot-and-mouth disease or hoof-and-mouth disease (Aphthae epizooticae) is an infectious and sometimes fatal viral disease that affects cloven-hoofed animals, including domestic and wild bovids.[1][2] The virus causes a high fever for two or three days, followed by blisters inside the mouth and on the feet that may rupture and cause lameness.


Susceptible animals include cattle, water buffalo, sheep, goats, pigs,[4][5] antelope, deer, and bison. It has also been known to infect hedgehogs and elephants;[3][6] llamas and alpacas may develop mild symptoms, but are resistant to the disease and do not pass it on to others of the same species.[3] In laboratory experiments, mice, rats, and chickens have been successfully infected by artificial means, but they are not believed to contract the disease under natural conditions.[3] Humans are very rarely infected.




FMD occurs throughout much of the world, and while some countries have been free of FMD for some time, its wide host range and rapid spread represent cause for international concern. After World War II, the disease was widely distributed throughout the world. In 1996, endemic areas included Asia, Africa, and parts of South America; as of August 2007, Chile is disease-free,[8] and Uruguay and Argentina have not had an outbreak since 2001. In May 2014, the FAO informed that Bolivia, Colombia, Ecuador and Peru were "just one step away" from eradication;[9] North America and Australia have been free of FMD for many years. New Zealand has never had a case of foot-and-mouth disease.[10] Most European countries have been recognized as disease-free, and countries belonging to the European Union have stopped FMD vaccination.


Clinical signs[edit]

Ruptured blisters on the feet of a pig

The incubation period for foot-and-mouth disease virus has a range between two and 12 days.[11][12] The disease is characterized by high fever that declines rapidly after two or three days, blisters inside the mouth that lead to excessive secretion of stringy or foamy saliva and to drooling, and blisters on the feet that may rupture and cause lameness.[4] Adult animals may suffer weight loss from which they do not recover for several months, as well as swelling in the testicles of mature males, and in cows, milk production can decline significantly. Though most animals eventually recover from FMD, the disease can lead to myocarditis [13](inflammation of the heart muscle) and death, especially in newborn animals. Some infected animals remain asymptomatic, but they nonetheless carry FMD and can transmit it to others.


Of the seven serotypes[14] of this virus, A, C, O, Asia 1, and SAT3 appear to be distinct lineages; SAT 1 and SAT 2 are unresolved clades.[15] The mutation rate of the protein-encoding sequences of strains isolated between 1932 and 2007 has been estimated to be 1.46 × 10−3 substitutions/site/year, a rate similar to that of other RNA viruses. The most recent common ancestor appears to have evolved about 481 years ago (early 16th century). This ancestor then diverged into two clades which have given rise to the extant circulating Euro-Asiatic and South African. This event occurred around 1800.[16] Skyline plot analysis shows a population expansion in the early 20th century, which was then followed by a rapid decline in population size in the late 20th century.

At least seven genotypes of serotype Asia 1 are known.[17]



Just as humans may spread the disease by carrying the virus on their clothes and bodies, animals that are not susceptible to the disease may still aid in spreading it. This was the case in Canada in 1952, when an outbreak flared up again after dogs had carried off bones from dead animals.[3] Wolves are thought to play a similar role in the former Soviet Union.[18]

Foot-and-mouth disease infecting humans[edit]






Currently, the World Organisation for Animal Health recognizes countries to be in one of three disease states with regards to FMD: FMD present with or without vaccination, FMD-free with vaccination, and FMD-free without vaccination.[22] Countries designated FMD-free without vaccination have the greatest access to export markets, so many developed nations, including Canada, the United States, and the UK, work hard to maintain their current status. Some countries such as Brazil and Argentina which have large beef exporting industries, practise vaccination in some areas but have other vaccination-free zones.





United States 1870–1929[edit]

The US has had nine FMD outbreaks since it was first recognized on the northeastern coast in 1870;[24] the most devastating happened in 1914. It originated from Michigan, but its entry into the stockyards in Chicago turned it into an epizootic. About 3,500 livestock herds were infected across the US, totaling over 170,000 cattle, sheep, and swine. The eradication came at a cost of US$4.5 million, a huge sum of money in 1914.



United Kingdom 1967[edit]


Taiwan 1997[edit]

Taiwan had previous epidemics of FMD in 1913–14 and 1924–29, but had since been spared,[27] and considered itself free of FMD as late as in the 1990s. On the 19th of March 1997, a sow at a farm in Hsinchu Prefecture, Taiwan, was diagnosed with a strain of FMD which only infects swine. Mortality was high, nearing 100% in the infected herd. The cause of the epidemic was not determined, but the farm was near a port city known for its pig-smuggling industry and illegal slaughterhouses. Smuggled swine or contaminated meat are thus likely sources of the disease.





Taiwan had previously been the major exporter of pork to Japan, and among the top 15 pork producers in the world in 1996. During the outbreak, over 3.8 million swine were destroyed at a cost of US$6.9 billion. The Taiwanese pig industry was devastated as a result, and the export market was in ruins.[25][dead link] [28][dead link] In 2007, Taiwan was considered free of FMD, but was still conducting a vaccination program, which restricts the export of meat from Taiwan.

United Kingdom 2001[edit]


China 2005[edit]


United Kingdom 2007[edit]



On 12 September, a new outbreak of the disease was confirmed in Egham, Surrey, 19 km (12 mi) from the original outbreak,[44] with a second case being confirmed on a nearby farm on 14 September.[45]


Japan and Korea 2010–2011[edit]


South Korea was hit by the rarer type A FMD in January, and then suffered type O infection in April.[46] The most serious case of foot-and-mouth outbreak in South Korea's history started in November 2010 in pig farms in Andong city of Gyeongsangbuk-do, and has since spread in the country rapidly.[47][48] More than 100 cases of the disease have been confirmed in the country so far,[47] and in January 2011, South Korean officials started a mass cull of approximately 12%, or around three million in total, of the entire domestic pig population, and 107,000 of three million cattle of the country to halt the outbreak.[47]


Bulgaria 2011[edit]

The outbreak was recognised when a wild boar was shot, which had crossed the Bulgarian-Turkish border near the village of Kosti, Burgas Province, in the Strandzha Mountains.[50] The necropsy uncovered foot-and mouth disease.[50] After this, 37 infected animals were discovered in the village of Kosti, and all susceptible animals there were culled. Burgas Province and seven other neighboring provinces declared a quarantine zone.[51]

On 14 January, a further outbreak was discovered in the neighboring village of Rezovo,[50] thought to have been carried by a Turkish cattle herd. On 17 January, the presence of the disease was confirmed.[50] The Bulgarian authorities ordered culling of all susceptible livestock in Rezovo.[52] Compensation for the losses in the two villages has been promised.[50]


Economic and ethical issues[edit]

Epidemics of FMD have resulted in the slaughter of millions of animals, despite this being a frequently nonfatal disease for adult animals (2–5% mortality), though young animals can have a high mortality.[54] The Taiwan outbreak that only affected pigs also showed a high mortality for adults. The destruction of animals is primarily to halt further spread, as growth and milk production may be permanently affected, even in animals that have recovered. Due to international efforts to eradicate the disease, infection would also lead to trade bans being imposed on affected countries. Critics of current policies to cull infected herds argue that the financial imperative needs to be balanced against the killing of many animals,[55] especially when a significant proportion of infected animals, most notably those producing milk, would recover from infection and live normal lives, albeit with reduced milk production. On the ethical side, one must also consider FMD is a painful disease for the affected animals.[56] The vesicles/blisters are painful in themselves, and restrict both eating and movement. Through ruptured blisters, the animal is at risk from secondary bacterial infections [56] and, in some cases, permanent disability.

See also[edit]


  1. ^ Arzt, J.; Juleff, N.; Zhang, Z.; Rodriguez, L. L. (2011). "The Pathogenesis of Foot-and-Mouth Disease I: Viral Pathways in Cattle". Transboundary and Emerging Diseases 58 (4): 291. doi:10.1111/j.1865-1682.2011.01204.x.  edit
  2. ^ Arzt, J.; Baxt, B.; Grubman, M. J.; Jackson, T.; Juleff, N.; Rhyan, J.; Rieder, E.; Waters, R.; Rodriguez, L. L. (2011). "The Pathogenesis of Foot-and-Mouth Disease II: Viral Pathways in Swine, Small Ruminants, and Wildlife; Myotropism, Chronic Syndromes, and Molecular Virus-Host Interactions". Transboundary and Emerging Diseases 58 (4): 305. doi:10.1111/j.1865-1682.2011.01236.x.  edit
  4. ^ a b
  5. ^
  8. ^ "Foot and Mouth Disease" (PDF). Washington State Department of Health. March 2002. Archived from the original on 2007-07-10. Retrieved 2007-08-05. 
  9. ^ [1]
  11. ^
  13. ^
  22. ^ "List of FMD free Member Countries". OIE. Retrieved 2014-08-04. 
  23. ^ Canadian Food Inspection Agency Q&A, question 20.
  24. ^ Correa Melo, E; López, A (2002). "Control of foot and mouth disease: The experience of the Americas". Revue scientifique et technique (International Office of Epizootics) 21 (3): 695–8, 689–94. PMID 12523707.  edit
  25. ^ a b EDEN
  26. ^ CRS Report for Congress—Foot and Mouth Disease: A Threat to U.S. Agriculture, Segarra, Rawson.
  27. ^ Foot-and-mouth virus: A global dilemma
  28. ^ US Department of Agriculture—Foreign Animal Report 1998, p41
  31. ^ DEFRA—Origin of the UK Foot and Mouth Disease Epidemic 2001
  32. ^ Jia Hepeng, China confirms bird flu and foot-and-mouth outbreaks
  45. ^ "Outbreak at second farm confirmed" BBC News
  49. ^ "Pork Prices Rising with FMD Meat on Sale". 
  50. ^ a b c d e Второ село беше пренесено в жертва на шапа—АГРО.БГ
  51. ^ Умъртвяват животни заради шап в Странджанско -
  52. ^ Шап плъзна в Резово, умъртвяват добитък -
  54. ^ Arzt, J; White, W. R.; Thomsen, B. V.; Brown, C. C. (2010). "Agricultural diseases on the move early in the third millennium". Veterinary Pathology 47 (1): 15–27. doi:10.1177/0300985809354350. PMID 20080480.  edit
  56. ^ a b [2][dead link] section 1.6.1

External links[edit]