Foot and Mouth Disease - Research Paper Example

?Topic:  Foot and Mouth Disease Introduction Foot and mouth disease is a disease which is caused to cloven hoofed animals including domesticated ruminants and pigs and more than 70 wildlife species. Foot and mouth disease is endemic in large areas of Africa, Asia and South America, and the infection has a remarkable ability to spread over long distances and to cause epidemics in previously free areas. Foot and mouth diseases are a major constraint to international trade in livestock and animal products. The animals which are under threat are cattle’s, pigs and small ruminants and, in particular in Asia and South America, the water buffalo. The animals which may contribute to the transmission of virus under certain conditions are deer, camels, llamas and Indian elephants. According to (IDG,2011)“The virus spread from one place to another by air especially when humidity of the air is high the virus easily spread from one place to another”. There have been many references in the scientific literature in the past of the occurrence of FMD in humans. In the vast majority of these cases the appearance of blisters and vesicular lesion has been due to the effect of other agents – including viruses. Under field conditions susceptible animals may be infected by FMDV as a result of direct or indirect contact with infected animals or an infected environment. Several recent outbreaks of FMD has been linked to the entry of virus in contaminated materials which has subsequently been fed to animals.FMD contact are influenced by influenced by many factors like stocking density, handling of animals and their rearing. Description of Foot and Mouth Disease FMD is an acute febrile disease characterized by the formation of vesicles in and around the mouth and on the feet. Lameness and inappetance are also often characterized features. As per(Hoenig,2005)“The disease is characterized by fever and blister like lesions followed by erosions on the tongue and lips, in the mouth, on the teats, and between the hooves”. Lesions may be initially being observed as blanched areas, which subsequently develop into vesicles at sites of local irritation and abrasions. Consequently, lesions are most often observed in and around the mouth and on the feet but may also be seen on the snout or muzzle, teats, mammary glands, prepuce , vulva and other sites of skin and mucosea. Animals kept outside on soft grounds or inside on soft bedding are less likely to develop severe foot lesions and show obvious lameness. Mortality in young animals, particular lambs and piglets, may be due to acute myocarditis. Occasionally, the skeletal muscles may also be affected. The significance of acute myocarditis in spread of the FMD has not been studied in detail. Death usually occurs rapidly and before the development of vesicular lesions; however FMDV replication levels are significant in heart, and it appears plausible that a significant viraemia occurs and that virus particles are excreted in breathe, saliva, nasal fluid and other excretions and secretions.FMD may also cause abortion in pregnant animals; however, the precipitating and specific mechanism involved had not been determined for the various livestock species. Epidemic and prevalence of the disease The endemic nature of foot and mouth disease in South America remained a constant problem facing its meat exporters. In 1870 to 1929 the United States experienced ten different outbreaks of foot and mouth disease from imports from Europe and South America. Two of these in 1914 and 1924 were particularly serious, costing tens of millions of dollars to eradicate. In the book(Perren,2006,pg.130)states that ,“A 1994 study conducted by the United States Department of Agriculture found that of 558 worldwide outbreaks of the disease between 1870 and 1993, only 2 percent of those occurring before 1969 has been caused by imported livestock”. But since 1969 imported animals had become the major cause of the disease, accounting for 36percent of outbreaks. There was an outbreak of 30 cases of FMD in Germany during 1970.In 2001, a confirmed case of FMD was announced on 19th February 2001, and the first outbreak on the UK mainland since 1968.Unlike the 1967 outbreak, the 2001 crisis reached all the parts of UK including England, Scotland, Wales and also Ireland. In reaction and due to the highly contagious nature of the disease, British exports were immediately banned by disease free importing nations. By the end of March, the disease was out of control as infected animals remained alive for days and contribute to further spread. The UK was therefore under pressure to regain trading status sooner than later and IOE status was regained on 22 January 2002. Symptoms of Foot and Mouth Disease FM D is a highly contagious viral disease affecting primarily cloven – hoofed animals, such as cattle, sheep, swine and goats- has 7 types and over 80 subtypes. The first symptom of infection in animal is high fever; blisters and ulceration develop on mouth and the feet, leading to lameness and poor feeding ability. FMD infected animals usually develop blisters like lesion in the mouth, on the tongue and the lips, on the teats, or between the hooves, which causes them to salivate excessively or become lame. Other symptoms include fever, reduced feed consumption and abortion. As per (prempey,2001,pg. 230-39) “Infected animals secrete numerous virus particles before clinical signs appear”. Cattle and pigs are very sensitive to the virus and show symptoms of the disease after a short incubation period of 3 to 5 days. The incubation period in sheep is considerable longer, about to 10 to 14 days, and the clinical signs of the disease are usually mild and may be masked by other conventional conditions. The FMD virus is easily transmitted and spreads rapidly. In the book (Dyckman,2002,pg.143)claims that ,“Prior to and during the appearance of clinical signs, infected animals release the virus into the environment through respiration, milk semen, blood, saliva and feces”. Symptoms normally resolve spontaneously, usually within a week of the last appearance of blistering. The clinical signs in cattle are most often obvious and include the drooling of saliva and rather sever vascular mouth lesions and lesions can be seen also on feet and elsewhere. Transmission and prevention of disease Foot and mouth disease is a microbial agent of particular concern because it is highly contagious and spreads very quickly throughout any given area. The causative agent of FMD is the Apthovirus, and transmission of the organism can occur through a variety of mechanism. In his book (Maier, 2009 ,pg.56)writes that “Sheep act as a maintenance hosts often without clinical signs, and can spread the virus to other susceptible animals”. Pigs act as an amplifier of the virus by producing 1000 times more virus particles than cattle. In addition, the virus can remain viable in a variety of materials including fecal materials, hay or soil for over 100 days. However, survival decreases with increasing heat and decreased humidity. Foot and mouth disease is spread rapidly within a locality by movement of infected animals to market by mechanical transmission on items such as clothes, shoes, vehicles, and veterinary instruments. Prevention of FMD is normally done through animal movement control and surveillance. Vaccination is also variable to reduce the potential impact of outbreaks. Outbreaks are normally controlled by the slaughter of all potential host animals and /or through vaccination. In the article(Wadsworth ,2008,pg.56-61)mentions that “Investigating and determining the source of these outbreaks has been imperative for their effective management and is vital for future prevention”. Along with this isolation of the infected animals and restriction of their movement is also necessary. It is also essential to keep an eye on the clinical signs of the diseases on the animals .Also the cleanliness of the farm is significantly important to avoid the emergence of foot and mouth disease among farm animals. Conclusion After the major epizootic of FMD in the UK in 1967-68 many investigations were made into the susceptibility of small British mammals to infection with virus. This work had two main purposes, i.e. the identification of possible vectors of the virus resulting in a mechanism for the transmission of infection to farm livestock and also the possibility of identifying additional species useful in laboratory investigation. Most of the routes of infection drive from experimental studies in animals infected with FMDV by simulated natural methods or in animals infected by artificial methods, including direct injection of virus. Several recent outbreaks of FMD have been linked to the entry of virus in contaminated material which has been subsequently fed to animals. Because of its highly contagious nature research work on FMDV is restricted to a small number of laboratories worldwide that have adequate contamination facilities. One popular explanation holds that veterinarians, politicians and farmers belatedly realized that FMD, was in fact, an extremely dangerous and damaging disease that had to be controlled by means of import and domestic trade restriction.FMD control is a national problem that could only be combated effectively by a policy that placed the interest of the nation above those of the region or the individual. As per (Ogunseitan,2005,pg.212) “Eradication of FMD usually requires the disposal of all animals that may have come in to contact with the virus – a very expensive preposition”.FMD is very important economically because it spreads rapidly and causes high morbidity, production losses, and obstacles for the marketing of livestock and product of animal origin. Bibliography Dyckman, L. (2002). Foot and Mouth Disease : To protect U.S.livestock (p. 143). Washington D.C.: DIANE Publishing Hoenig, D. (2005). Foot-and-Mouth Disease. In Maine.gov. Retrieved October 20, 2011, from http://www.maine.gov/agriculture/ahi/diseases/fmd.html IDG(2011, May 25). Foot and mouth disease. In India Development Gateway. Retrieved October 19, 2011, from http://indg.in/agriculture/animalhusbandary/foot-and-mouth-disease. Maier, R. M. (2009). Environmental Microbiology (2,nd ed., p. 56). London: Elsevier Inc. Ogunseitan, O. (2005). Microbial diversity: form and function in prokaryotes (p. 212). Oxford: Blackwell Publishing Co. Prempeh, Henry.(2001,March 10) "Foot and mouth disease: the human consequences." BMJ 322 (7286), 230-39. Perren, R. (2006). Taste, Trade and Technology: the development of international meat market industry since 1840 (p. 130). Hants: Ashgate Publishing Ltd. Wadsworth, C. (2008, April 25). Transmission Pathways of Foot-and-Mouth Disease Virus in the United Kingdom in 2007. PLOS Pathogens, 4(4), 56-61. Read More