Foot and mouth disease or nail and mouth disease ( Aphthae epizooticae ) is an infection and sometimes a fatal viral illness attacking hoofed animals, including domestic and wild bovids. The virus causes high fever for about two to six days, followed by blisters in the mouth and in legs that can rupture and cause lameness.
Foot and mouth disease (PMK) has very severe implications for animal farming, as it is highly contagious and can be spread by relatively infected animals easily through contact with agricultural equipment, vehicles, clothing, contaminated feed and by domestic and wild predators. His detention demands great efforts in vaccinations, rigorous monitoring, trade restrictions, quarantine and sometimes animal extermination.
Vulnerable animals include cows, buffaloes, sheep, goats, pigs, antelopes, deer, and bulls. Also known to infect hedgehogs and elephants; llamas and alpacas can develop mild symptoms, but are resistant to illness and do not pass it on to others of the same species. In laboratory experiments, rats, mice, and chickens have been successfully infected by artificial means, but they are not believed to have the disease under natural conditions. Humans are very rarely infected.
The virus responsible for this disease is picornavirus, a prototype member of the genus Aphthovirus . Infection occurs when virus particles are brought into the host cell. The cell is then forced to produce thousands of copies of the virus, and eventually explodes, releasing new particles in the blood. The virus is genetically highly variable, limiting the effectiveness of vaccination.
Video Foot-and-mouth disease
History
The cause of FMD was first shown to be viral in 1897 by Friedrich Loeffler. He passed the blood of infected animals through Chamberland filters and found the collected fluid can still cause disease in healthy animals.
FMD occurs in most parts of the world, and while some countries have been free of FMD for some time, its broad range of hosts and rapid deployment are a cause of international concern. After World War II, the disease was widespread throughout the world. In 1996, endemic areas included Asia, Africa, and parts of South America; in August 2007, Chile was disease-free, and Uruguay and Argentina have not experienced an outbreak since 2001. In May 2014, the FAO informed that Bolivia, Colombia, Ecuador and Peru "only one step" of eradication; North America and Australia have been free of FMD for years. New Zealand has never had cases of foot and mouth disease. Most European countries have been recognized as disease-free, and EU member states have discontinued FMD vaccinations.
However, in 2001, a serious UK FMD outbreak resulted in the slaughter of many animals, month-long election delays, and the cancellation of many sporting events and recreational activities, such as the Isle of Man TT. Due to the government's strict policy on the sale of livestock, the disinfection of all those leaving and entering the farm, and the cancellation of a large event likely to be attended by farmers, a potentially disaster avoided economic epicootic in the Republic of Ireland, with only one case recorded at Proleek, Co Louth. In August 2007, FMD was found on two farms in Surrey, England. All cattle were destroyed and quarantine was erected on top of the area. Two other suspected outbreaks have occurred since, although these appear to be unrelated to FMD. The only case reported in 2010 was a fake alarm from GIS Alex Baker, which was proven wrong by the Florida Department of Agriculture and Agriculture, and quarantine/cow and pork slaughtering was confirmed from Miyazaki Prefecture in Japan in June after three cows were tested positive. A total of 270,000 livestock have been ordered slaughtered after the pestilence.
Maps Foot-and-mouth disease
Clinical signs
The incubation period for oral and nail disease viruses ranges from one to 12 days. The disease is characterized by high fever that decreases rapidly after two or three days, blisters in the mouth causing excessive secretion of fibrous or foaming saliva and drooling, and abrasions on the legs that can rupture and cause lameness. Animals may suffer weight loss from which they have not recovered for several months, as well as swelling of the adult male testes, and in cattle, milk production may decrease significantly. Although most animals eventually recover from FMD, the disease can cause myocarditis (inflammation of the heart muscle) and death, especially in newborn animals. Some infected ruminants remain as carriers without symptoms, but they still carry FMDV and may be able to pass it on to others. Pigs can not function as carriers without symptoms.
Evolution
Of the seven serotypes of this virus, A, C, O, Asia 1, and SAT3 appear to be distinct lineages; SAT 1 and SAT 2 are unresolved clades. The rate of mutation of protein encoding sequences from strains isolated between 1932 and 2007 has been estimated to be 1.46 ÃÆ'â € "10 -3 substitution/site/year, a level similar to that of other RNA viruses. The latest common ancestors seem to have evolved about 481 years ago (early 16th century). This ancestor then deviates into two clades that have given rise to the existing Euro-Asiatic and South African circulation. SAT 1 deviated first 397 years ago, followed by sequential aberrations serotype SAT 2 (396 years ago), A (147 years ago), O (121 years ago), Asia 1 (89 years ago), C ( 86 years ago), and SAT 3 (83 years ago). The Bayesian skyline plot reveals a population expansion in the early 20th century followed by a rapid decline in population size from the late 20th century to the present day. In each serotype, there is no real, periodic, geographic or organizational species influence on the evolution of the global FMDV. At least seven genotypes of Asian serotype 1 are known.
Transmission
The FMD virus can be transmitted through a variety of ways, including animal-to-animal spread from close range, long-range aerosol deployment and fomites, or inanimate objects, usually fodder and motor vehicles. Clothes and skins of animal handlers such as farmers, puddles, and unsaved food scraps and dietary supplements containing infected animal products can also be a source of virus. Cattle can also catch FMD from infected cow's semen. Control measures include quarantine and the destruction of infected livestock, and export restrictions on meat and other animal products to non-infected countries.
Just as humans can spread disease by carrying viruses to their clothing and bodies, animals that are not susceptible to this disease can still help spread it. This was the case in Canada in 1952, when the outbreak erupted again after dogs carried bones from dead animals. Wolves are thought to play a similar role in the former Soviet Union.
Daniel Rossouw Kannemeyer (1843-1925) published a note in the 'Transactions of the Philosophical Society of South Africa' volume 8 part 1 where he connected the spit-covered locusts with the spread of the disease.
Infecting humans
Humans can be infected with foot and mouth disease by contact with infected animals, but this is very rare. Some cases are caused by laboratory accidents. Because the virus that causes FMD is sensitive to stomach acid, it can not spread to humans through consumption of infected meat, except in the mouth before the meat is swallowed. In Britain, the last confirmed human case occurred in 1966, and only a few other cases were recorded in continental European countries, Africa, and South America. FMD symptoms in humans include malaise, fever, vomiting, red ulcerative lesions (stains that erode the surface) of the mouth tissue, and occasionally vesicular lesions (small blisters) on the skin. According to a newspaper report, FMD killed two children in Britain in 1884, allegedly due to infected milk.
Other viral diseases with similar symptoms, hand, foot and mouth disease, occur more often in humans, especially in young children; the cause, Coxsackie A virus, is different from FMDV. The Coxsackie virus is included in Enteroviruses in Picornaviridae.
Because FMD rarely infects humans, but spreads rapidly among animals, it is a far greater threat to the agricultural industry than human health. Farmers around the world can lose huge amounts of money during ejaculation of the mouth and feet, when large numbers of animals are destroyed, and income from milk and meat production falls.
Vaccinations
Like other viruses, the FMD virus continues to evolve and mutate, so one of the difficulties in vaccination against it is the great variation between, and even within, serotypes. There is no cross protection between serotypes (a vaccine for one serotype will not protect against another) and in addition, two strains in a particular serotype may have 30% different nucleotide sequences for the given gene. This means the FMD vaccine must be very specific to the strains involved. Vaccinations only provide temporary immunity that lasts from month to year.
Currently, the World Organization for Animal Health recognizes countries to be located in one of three FMD-related disease states: FMD comes with or without vaccination, FMD-free with vaccination, and FMD-free without vaccination. Countries designated FMD-free without vaccination have the greatest access to export markets, so many developed countries, including Canada, the United States and Britain, are working hard to maintain their current status. Some countries like Brazil and Argentina that have a large beef exporting industry, vaccinate in some areas but have other vaccination-free zones.
The reasons cited for limiting exports from countries that use the FMD vaccine include, perhaps most importantly, routine blood tests that rely on antibodies can not distinguish between infected animals and vaccinated animals, which severely inhibits the filtering of animals used in export products, risking the spread of FMD to import countries. Large prevention vaccinations will also hide the presence of virus in a country. From there, it could potentially spread to countries without a vaccine program. Finally, infected animals immediately after vaccination can store and spread FMD without showing the symptoms themselves, inhibiting the detention and annihilation of sick animals as medication.
Many early vaccines use dead FMDV samples to inject animals, but the initial vaccine sometimes causes a real outbreak. In the 1970s, scientists discovered that vaccines could be made only by using one key protein from the virus. His job is to produce enough protein to be used in vaccinations. On June 18, 1981, the US government announced the production of a vaccine targeted against FMD, the world's first genetically engineered vaccine.
Vaccine Bank FMD North America is housed in the Laboratory of Animal Disease Diagnostic of the United States Department of Agriculture at Plum Island Animal Disease Center. The center, located 1.5 m (2.4 km) off the coast of Long Island, NY, is the only place in the United States where scientists can conduct research and diagnostics working on highly infectious animal diseases such as FMD. Due to this limitation, US companies working in FMD typically use facilities in other countries where the disease is endemic.
Outbreak
United States 1870-1929
The United States has experienced nine FMD outbreaks since it was first discovered on the northeast coast in 1870; the most devastating occurred in 1914. It originated in Michigan, but its entry into a cattle storage in Chicago turned it into an epizootic. Approximately 3,500 livestock are infected throughout the US, totaling more than 170,000 cattle, sheep and pigs. Eradication came at a cost of US $ 4.5 million, a large sum of money in 1914.
The 1924 epidemic in California resulted not only in the massacre of 109,000 farm animals, but also 22,000 deer.
The US has the latest FMD outbreak in Montebello, California, in 1929. This outbreak came from pigs that have eaten infected meat from tourist steamers that have been stockpiling meat in Argentina. More than 3,600 animals were slaughtered and the disease was contained in less than a month.
Mexico-US. border 1947
Outbreaks on the US-Mexican border resulted in a bilateral effort to eradicate the disease. That is a sign that the US-Mexico relationship improved in the post-World War II era.
United Kingdom 1967
In October 1967, a farmer in Shropshire reported a weak pig, which was later diagnosed with FMD. The source is believed to be the legally imported sheep meat from Argentina and Chile. The virus spread and, in total, 442,000 animals were slaughtered and the plague was estimated to cost around £ 370 million.
Taiwan 1997
Taiwan had an earlier FMD epidemic in 1913-14 and 1924-29, but has since been spared, and considers himself free from FMD until the late 1990s. On March 19, 1997, a pig on a farm in Hsinchu Prefecture, Taiwan, was diagnosed with an FMD strain that only infects pigs. The mortality rate is high, close to 100% in the infected flock. The cause of the epidemic is not specified, but the farm is near the port city known for its smuggler-smuggling industry and illegal slaughterhouses. Pork or contaminated meat is a source of disease.
The disease is spreading rapidly among Taiwan's swine herds, with 200-300 newly infected farms daily. Causes for this include high pig densities in the area, with up to 6,500 pigs per square mile, feeding pigs with untreated trash, and proximity to farms with slaughterhouses. Other systemic problems, such as lack of laboratory facilities, slow response, and lack of early vaccination programs, contribute. Farmers allegedly deliberately introduced FMD to their livestock, because the payments offered to farmers to slaughtered pigs at that time were higher than their market value.
A troubling factor is the spread of endemic vesicular disease pigs (SVD) in Taiwan. The symptoms are indistinguishable from FMD, which may lead to a previous FMD diagnostic error as an SVD. Laboratory analysis is rarely used for diagnosis, and FMD may be overlooked for some time.
The loss of the pig population is a major undertaking, with the military contributing considerable energy. At peak capacity, 200,000 pigs per day are discarded, mainly by electricity. Carcasses are discharged by burning and burial, but combustion is avoided in water resources protection areas. In April, industrial incinerators ran all the time to dispose of carrion.
Initially, 40,000 combined doses of vaccine for the O-1, A-24, and Asia-1 strains were available and administered to valuable zoo animals and breeding pigs. By the end of March, half a million new doses for O-1 and Asia-1 are available. As of May 3, 13 million doses of the O-1 vaccine arrived, and deliveries in March and May were distributed for free. With the dangers of vaccination crews spreading the disease, only trained farmers are allowed to manage vaccines under veterinary supervision.
Taiwan has previously been a major exporter of pork to Japan, and among the top 15 pork producers in the world in 1996. During the outbreak, more than 3.8 million pigs were destroyed at a cost of US $ 6.9 billion. Taiwan's pig industry is destroyed as a result, and the export market becomes a ruin. In 2007, Taiwan was considered FMD free, but still conducts vaccination programs, which restrict meat exports from Taiwan.
English 2001
The epidemic of mouth and nail disease in England in the spring and summer of 2001 was caused by the "Type O pan Asia" strain of the disease. This episode produced more than 2,000 cases of disease in farms throughout the English countryside. About ten million sheep and livestock were killed in an attempt to finally stop the disease. The area of ​​Cumbria is the area most seriously affected in the country, with 843 cases. By the time the disease was stopped in October 2001, the crisis was estimated to cost  £ 8 billion ($ 13 billion) to agricultural and support industries, and for outdoor industries. What makes this outbreak very serious is the amount of time between infections present at the first epidemic locus, and the time when countermeasures are put into operation against the disease, such as transportation and laundry detergents from both vehicles and personnel entering the farm area. This epidemic may be caused by pigs fed infected waste that have not been properly sterilized. Furthermore, the waste is believed to contain the remains of infected meat that has been illegally imported into the UK.
China 2005
In April 2005, the FMD Asia-1 strain emerged in the eastern provinces of Shandong and Jiangsu. During April and May, it spread to the suburbs of Beijing, northern Hebei province, and the Xinjiang autonomous region in northwestern China. On May 13, China reported the FMD outbreak to the World Health Organization and OIE. This is the first time China has publicly admitted having an FMD. China still reports the FMD outbreak. In 2007, reports submitted to the OIE documented new or ongoing epidemics in Gansu, Qinghai and Xinjiang provinces. These include domestic yak reports that show signs of infection. FMD is endemic in Chinese pasturegies from Heilongjiang Province in the northeast to Sichuan Province and the Tibetan autonomous region in the southwest. Chinese domestic media reports often use the euphemism of "Number Five Illness" (??? w? HÃÆ' obÃÆ'¬ng ) than in the FMD report because of the sensitivity of the FMD problem. In March 2010, Southern Rural News (Nanfang Nongcunbao ), in the article "Solving Taboo of Nail and Mouth Diseases", notes that FMD has long been covered up in China by referring that. FMD is also called canker (??, literally "mouth ulcers" k? Uchu? Ng ) or jaundice nails (?? tÃÆ'huÃÆ'¡ng ) in China, so information about FMD in China can be found online using those words as search terms. One can find many provincial commandments and regulations online regarding FMD controls which accuse China of recognizing that the disease exists in China, for example the Guangxi Zhuang Autonomous Region regulations 1991 on the prevention of the spread of Disease No.5.
English 2007
Infection of mouth and nail disease in the UK was confirmed by the Department of Environment, Food and Rural Affairs, on August 3, 2007, on a farmland located in Normandy, Surrey. All of the surrounding cattle were destroyed on 4 August. The national ban on the movement of livestock and pigs is enforced, with a 3 km (1.9-mile) protection zone stationed around the outbreak site and nearest viral research and the establishment of vaccine production, along with 10 km (6.2 mi). ) improvement of surveillance zones.
On August 4, the strain of the virus was identified as the "01 BFS67-like" virus, which is associated with the vaccine and is not usually found in animals, and isolated in 1967. The same strain was used at the nearby Institute for Animal Health and Merial Animal Health Ltd at Pirbright, 2.5 miles (4.0 km), which is an American/French research facility, and identified as a possible source of infection.
On September 12, a new outbreak was confirmed in Egham, Surrey, 19 km (12 miles) from the original outbreak, with a second confirmed case at a nearby farm on 14 September.
This outbreak led to the wasting of all risky animals in the area around Egham, including two farms near the famous Four Fosters four star hotel. The epidemic also caused the closure of Windsor Great Park because of deer-containing parks; the park remained closed for three months. On September 19, 2007, the alleged FMD case was found in Solihull, where the temporary control zone was established by Defra.
Japan and Korea 2010-2011
In April 2010, reports of three PMK attacks in Japan and South Korea led the Food and Agriculture Organization of the United Nations (FAO) to issue a call to step up global oversight. Japanese veterinary authorities confirm outbreaks of the FMD type O virus, currently more common in Asian countries where FMD is endemic.
South Korea was hit by a rare type A FMD in January, and later suffered type O infection in April. The most serious case of foot and mouth plague in South Korea's history began in November 2010 at a pig farm in Andong Gyeongsangbuk-do city, and has since spread rapidly in the country. More than 100 cases of disease have been confirmed in the country so far, and in January 2011, South Korean officials started mass destruction of about 12%, or about three million total, of the entire domestic pig population, and 107,000 of the country's three million livestock to stop the outbreak. According to reports based on a complete 1D gene sequence, the Korean A serotype is associated with people from Laos. The Korean O virus serotype is divided into three clades and is closely related to isolates from Japan, Thailand, England, France, Ireland, South Africa, and Singapore, as well as Laos.
On February 10, 2011, North Korea reported an outbreak of pig attacks in the area around Pyongyang, which then lasted at least since December 2010. Efforts to control the outbreak were hampered by the sale of infected meat.
Economic and ethical issues
Source of the article : Wikipedia
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