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On Wednesday, 21st February, a pig, spotted by an astute young vet at an abattoir in Essex, was confirmed as being infected by the foot-and-mouth virus. By the afternoon of the following Tuesday it had become clear that the outbreak was widespread and the UK Government issued the necessary order to local authorities allowing them to close all cross country rights of way under their jurisdiction and to impose a £5000 fine for disregard of this order. This is not an hour by hour information site. For up to the hour information about the spread of the disease and measures being implemented, refer to the contact sites and telephone numbers above. This site contains some general background information on the Foot and Mouth Disease Virus (FMDV). A General Introduction to Foot and Mouth Disease Foot and mouth disease (FMD) is a viral disease which can infect many mammals including, contrary to widespread belief, man (See foot-and-mouth disease infection of humans). To most species it is unimportant and, indeed, in humans usually goes unnoticed. To cattle and deer it is very serious, although not fatal in many cases of infection - a fact that has led to some ill-informed speculation that FMDV is not so serious as to deserve the measures currently being implemented. In many countries in Asia, Africa and South America the disease is endemic. Here it is taken as just a fact of livestock farming and when an outbreak occurs it is allowed to run its course. Some very young, old or already unhealthy animals die, but most recover and having done so acquire at least some immunity to subsequent infection. The question has been asked recently, from a number of different sources, as to why we just do not do this in the EU. In fact, the disease is not a minor infection and causes the animal considerable distress. It has been compared to leprosy (from which infected animals and people also often recover). During the course of an infection the affected animal ceases to produce milk and looses much weight. Infected tissues of the mouth, udder and hoof cause the animal obvious pain and distress. Affected animals cannot feed or walk and frequently cannot even stand. However, as far as the DEFRA and the Treasury are concerned the (complex) economic considerations alone are sufficient for Europe to maintain its "disease free" status. (See Vaccination and the Economics of FMD.) While somewhat less serious in sheep, goats and pigs than in cattle and deer, movement of sheep around the country appears to have been mainly responsible for the rapid spread of the disease during the early weeks of this outbreak. Further, pigs in particular exhale very large numbers of virus particles with each breath, so sheep and pigs play an important role in the transmission of the disease between cattle herds. (See Sheep, Goats and Pigs.) So far, there have been only a handful of cases of pig units being infected during the current epidemic. FMDV infection in most ungulates (hoofed animals) causes mouth and hoof blisters (from which it takes its name) and a general 'wasting' which results in the cessation of milk production in dairy cattle and a severe loss of weight in beef cattle. In effect, it ends productive cattle farming. In addition to the purely practical and economic consideration, it is a very distressing disease, particularly in cattle and deer which often suffer terribly. The incubation period for foot-and-mouth disease (that is, the period of time between infection and symptoms of the disease becoming visible, rather than the time between infection and the animal itself becoming infective to other animals, which may be very short) is generally taken to be between one and two weeks. It can be as short as two days (and the animal could be infective after a little as eight hours). Alternatively, the incubation period in exceptional cases can be as long as four weeks. In assessing reports as to the effectiveness of measures being taken to bring the disease under control, containing the spread of the disease and finally eradicating the virus from the country, this incubation period has to be kept in mind. As one hears the figures for new outbreaks, one has to remember that what one is hearing are the numbers of farms infected a couple of weeks ago and not the results of measures implemented in the recent past. Advice for 'tourists' and 'residents' This is a matter of common sense and public responsibility. Everyone now is aware of the risks and what constitutes responsible behaviour. The current advice from DEFRA is:
The Cause of Foot and Mouth Disease Foot and Mouth Disease is caused by a tiny organism called a virus. There are thousands of different types of virus classified into dozens of different 'families'. FMDV belongs to a family called Picornaviruses - a Latin name meaning very small beasts. For more detailed information about the Foot and Mouth Virus, see The Transmission of FMDV and Selected Technical Information. The strain of the virus responsible for the current epidemic (technically known as the "Pan-Asian topotype O-strain FMDV") is a fairly new variety. All epidemic varieties FMDV are counted amongst the most infectious organisms known but, even amongst the various forms of this viruse, this particular varient is exceptionally virulent. It was first detected eleven years ago in India, from where it spread eastwards into Korea, China and Mongolia. Recently, there have been reported outbreaks in Japan and South Africa. It is suspected that outbreaks of this strain may have occurred in a number of other countries, but that these have either not been identified or not reported. In common with other picornaviruses, FMDV multiples very rapidly following infection. An animal is infectious and capable of passing the disease on to other animals from as little as eight hours after exposure to the virus, although it will not show symptoms until at least two days from infection, and in some cases infected animals never display any visible symptoms. Disinfection The Foot and Mouth Disease Virus has a weak spot. It is sensitive to what chemists call pH - it falls to anything that is mildly acidic or reasonably alkaline. It is also vulnerable to any chlorinating agents, such hypochlorite bleach. A full list of effective disinfectants can be found at http://www.defra.gov.uk. Note that alcohol or petroleum based agents (often used to disinfect) are not effective against either FMDV or the distantly related swine fever. Dousing with surgical spirit, petrol, paraffin or with oil will not destroy the virus. (See also Detailed Technical Information) The Possible Infectivity of Animal Carcasses As discussed above, living animals that the disease does not infect, or in which it causes mild or no symptoms (including man) can spread the disease. Whether the virus can be spread by birds is not known. (Very few birds routinely travel significant distances.) The virus can be transmitted directly (by contact with saliva or burst blisters) and by the wind, particularly when in the form of an aerosol from the breath of infected animals. (See The Transmission of FMDV.) Dead (non-breathing) animals, including carcasses in closed vehicles in transit to a place of safe disposal, are believed by Government advisers to constitute a negligible hazard. In addition, the virus is sensitive to changes in acidity (see Selected Technical Information). Following death, muscle rigor results in an increase in the acidity of animal tissues, which in turn is believed to (somewhat) reduce the possibility of infection by carcass meat (and hence by transmission by way of scavengers such as rats). Carcasses are also sprayed with disinfectant following slaughter. For this reason, transport of carcasses to disposal sites is not thought to pose a threat. Nevertheless, transport of slaughtered sheep for burial by the army in Cumbria is currently only being carried out with animals that have been slaughtered as a precaution against further spread of the virus but which have not been diagnosed as being infected. In addition, transport of carcasses in Cumbria is currently only being carried out through areas already infected by the disease. Foot-and-Mouth Disease in Other British Wild Animals Foot-and-mouth disease only affects mammals. Britain has 66 native wild mammal species and a handful of introduced feral species (some of which, such as certain deer species, are present in considerable numbers). Of these, only deer, wild boar and hedgehogs have been found to carry the virus. The special case of the infection of Britains wild deer is covered in a separate section For some species, such as marine mammals, no data at all exist - a significant point a suggestion to dispose of infected animal carcasses by dumping at sea is currently being considered. Surprisingly little is known about the degree to which FMD affects wild animals in the UK - mainly because the country has been free of the disease for so long. However, there is a near unanimous consensus that wild mammals are not a serious concern, either as a persistent pool of FMDV or as vectors spreading the virus. Of course, all mammals have the potential of spreading the disease mechanically, in their fur, without themselves being infected. Experience from previous epidemics suggests that away from the intensive conditions of the modern livestock husbandry the virus does not thrive or persist in the UK. Following the 1967 outbreak, a latent pool of the virus was not found in wild mammal species, nor did wild animals hinder the eradication of the disease from domestic populations during the outbreak. The one wild British mammal which might pose a threat is the wild boar, recently released in the English midlands and which were not present during the 1967-8 outbreak. As with domestic pigs, wild boar would be expected to release very large numbers of viral particles if infected. Further, during the mating season, wild boar will actively seek our domestic sows. However, Britain's population of wild boar is not anticipated as a significant threat because of the very small numbers of animals in the wild. Horses and Foot-and-Mouth Disease Foot-and-mouth affects horses in a way which is comparable to foot-and-mouth in humans - that is, horses do not get ill with the disease, but they can become infected without symptoms. If they do, as with humans, they can pass the disease to other animals, such as cattle, sheep and pigs. For this reason it is important that horses be kept away from other livestock. The advice is only to ride on the roads or on one's own private land during the epidemic. It is also advisable to treat riding clothes as if they are potentially contaminated. Remember, deer can become badly infected by FMDV, and can contaminate areas where no domestic animals have grazed, from where horses (as well as people and pets) can acquire the virus. As far as horses themselves are concerned, the virus is no threat.
For more detailed information of horses and FMD see Equine World UK on this subject. |
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As from this week (commencing Sunday, 27th January, 2002) the UK has been restored to the status of Foot-and-Mouth disesase free. This site is now closed. For a brief resumé of the final statistics, click here |