Health & Management / Foot & Mouth Disease Module / List of hyperlinked Techniques & Protocols:
< > 

FMD Diagnosis, Surveillance & Carriers:

Click image to return to Foot-and-Mouth Disease CONTENTS
FLOWCHART

Introduction and General Information

In most countries the government MUST BY NOTIFIED if Foot-and-Mouth Disease occurs or is suspected.
This is a usually a statutory requirement and is enforced through National legislation.

Rapid detection and rapid, definite and accurate diagnosis of foot-and-mouth disease (FMD) is extremely important in controlling this highly-contagious disease. Delays in detection and diagnosis may lead to wide dissemination of the disease, making control more difficult.

It is important to make sure that FMD will be recognised or at least suspected rapidly on the basis of clinical signs. Information on clinical signs must allow diagnosis or suspicion by vets and farmers who have never seen this disease before. Diagnostic facilities must be available for rapid and accurate definite diagnosis of this disease. During an epidemic, rapid, accurate detection of disease is essential for effective control measures. Failure to correctly diagnose the disease could lead to delay in control, while false positives may result in unnecessary culling and wasteful diversion of resources.

Since surveillance initially relies heavily of farmers detecting cases, it is important to actively encourage reporting, by media campaigns, veterinary visits etc. to increase awareness, and by ensuring farmers are compensated fairly for infected livestock. It is also important for farmers to be aware of the variation in signs between species, and the need for extra vigilance in checking sheep and goats.

Note: Because FMDV is highly contagious, and due to the economic importance of FMD:

  • Samples from suspected cases of FMD must be transported under secure conditions, to authorised laboratories. Laboratory diagnosis and serotyping should be carried out in a facility meeting requirements for the containment of Group 4 pathogens. This may be a national or regional laboratory, or an FMD Reference Laboratory. (W31.Sept07.w4)
  • Proper biosecurity precautions are essential to ensure that qualified personnel employed in surveillance and diagnosis do not transfer virus between premises.

(J3.102.w6, J3.131.w1, J3.153.w6, J3.155.w3, J3.159.w1, J67.78.w1, J70.17.w1, J112.25.w4, J249.91.w2, B209, B210.89.w89, B495.7.w7 -full text provided, D37.Para216).

Diagnostic tests and standards, including sample selection and transportation, for use in the EU are set out in COUNCIL DIRECTIVE 2003-85-EC of 29 September 2003 on Community measures for the control of foot-and-mouth disease - Annex XIII- full text provided

The roles of National Laboratories and the Community Reference Laboratory are set out in COUNCIL DIRECTIVE 2003-85-EC of 29 September 2003 on Community measures for the control of foot-and-mouth disease - Annex XV and Annex XVI - full text provided

Following an outbreak, surveillance is essential to confirm that the disease has been controlled and, if required for international disease status purposes, to ensure that all animals which have been infected have been removed from the population.

  • Additionally, it is important to be able to distinguish between animals which have been vaccinated and those which have been infected. This is important for international trade, particularly if vaccination is used to control an FMD outbreak in an area which is normally FMD free. (J35.167.w2)
Published Guidelines linked in Wildpro

Return to top of page

Clinical signs that indicate FMD

Initial diagnosis or suspicion of foot-and-mouth disease is based on clinical assessment.
  • FMD should be suspected whenever mouth lesions and/or foot lesions/lameness develop in an animal of a susceptible species at any one time. The mouth and feet should then be examined for vesicles.
  • Suspicion should be aroused when lameness develops in a number of animals, particularly if this occurs in more than one species at the same time.
  • Suspicions should be aroused whenever one or more animals are noted to be salivating excessively.
  • Provisional diagnosis is usually based on clinical evidence: a highly contagious disease with vesicular lesions on the tongue and feet of bovines, pigs, sheep, goats and/or other susceptible species.
    • IN CATTLE: FMD is usually acute and relatively unmistakable.
      • Vesicles, which may affect the mouth and/or feet and/or teats.
      • Resentment of milking (associated with sore teats and/or viral mastitis), excess salivation (slavering) and chewing movements / lip-smacking (associated with mouth lesions), foot tenderness, lameness and/or foot shaking (associated with foot lesions).
      • General signs: fever, dullness, depressed appetite (animals off their feed), shivering, considerably decreased milk yield, lying down.
    • IN SHEEP AND GOATS: clinical signs may be less obvious and clear-cut, however the occurrence of a sudden-onset severe lameness in several animals at one time is suspicious.
      • Sudden death in apparently health lambs, abortions, and adult sheep which are listless and off their food may also be suspicious signs, particularly during an FMD outbreak.
      • In goats, reduced milk yield and abortions are common signs; appetite may be unaffected and lameness may not be obvious.
    • IN PIGS: clinical signs may not be so clear-cut as in cattle, but they show fairly typical signs. The occurrence of a sudden-onset severe lameness in several animals at one time is suspicious, and animals may also have high temperatures and be off their feed. Animals frequently lie down.
      • Lameness is more likely to be obvious if the pigs are on concrete or other hard surfaces than if they are on straw or similar soft bedding.
      • Piglets may die suddenly without previous clinical signs.
      • Vesicles may be variable in size, from small to quite large, and may develop on the coronets, mouth and snout and the teats of recently-farrowed sows.
      • FMD should always be suspected in pigs with vesicular lesions.
  • N.B.  Initial diagnosis may be difficult if strains produce unusual disease pictures: this is not uncommon with FMD.
  • It is important to remember that clinical signs vary between species and that signs in small ruminants may be subtle.
(J3.102.w6, J63.14.w1, J112.25.w4, B47, B58, B209, B210.89.w89, B495.7.w7 -full text provided, W16, W32.Apl01.sib1, D36.Appendix I).)
Associated techniques linked from Wildpro

Return to top of page

Other diseases that look like FMD

A variety of other diseases may produce signs similar to those which may be seen in animals with FMD. In particular, there are three other viral diseases which cause vesicles. Two of these are seen in pigs only, and one affects horses as well as cloven-footed animals.

FMD lesions are not always seen at the vesicle stage, and the disease does not always cause obvious vesicles. Depending on the circumstances and the species concerned, lesions may be noticed at the stage when they are already erosions or scabbed over, or when secondary bacterial infection has occurred. For these reasons there are a wide variety of other diseases which may, in one species or another, cause clinical signs which could also be caused by FMD.

PLEASE REMEMBER: an animal can have more than one disease active at one time.

  • Diseases producing vesicles which may affect the mouth and feet
    • Vesicular stomatitis (cattle, pigs, horses, sometimes sheep/goats)
    • Swine vesicular disease (pigs only)
    • Vesicular exanthema (pigs only)
    • Sunlight-induced dermatitis causing snout and sometimes foot vesicles in white-skinned pigs fed parsnips or celery
    • Rarely, fungal lesions may produce confusing skin lesions
    • (In humans, hand, foot and mouth disease)
  • Diseases which may produce lesions affecting the mouth and feet, but not vesicles
    • Mucosal disease (BVD/MD) (no vesicles, lesions begin as erosions)
    • Bluetongue (sheep, goats, rarely cattle)
    • Orf (Contagious pustular dermatitis)
    • Malignant catarrhal fever (foot lesions rare)
  • Diseases which may produce mouth lesions, but not vesicles and not foot lesions:
    • Rinderpest (no vesicles, lesions begin as erosions)
    • Bovine papular stomatitis
    • Epizootic haemorrhagic disease of deer
    • Infectious bovine rhinotracheitis
    • Lumpy skin disease (Bovine herpesvirus 2: Allerton strain)
      • In African buffalo in East Africa. Well-defined ulcers on the tongue, palate and buccal mucosae.
  • Diseases which may produce foot lesions, but not vesicles and not mouth lesions
    • Foot rot
    • Interdigital dermatitis (scald)
  • Diseases which may produce udder lesions
    • Pox infections of the udder (e.g. Cowpox, Pseudocowpox, Orf)
    • Bovine herpes mammilitis
  • Disease producing skin lesions, in elephants
    • Elephantpox
  • Disease producing neonatal mortality
    • Enterotoxaemia
    • Bluetongue
    • Encephalomyocarditis virus disease

N.B.

  • Cattle fed grain treated with caustic soda may salivate profusely.
  • Ingestion of any caustic material may result in salivation and oral blisters (vesicles).
  • Trauma may cause lesions similar to those seen with FMD.
  • Abscesses, e.g. at the coronary band, may appear similar to FMD vesicles.
  • Idiopathic mouth ulcers may be seen in both sheep (particularly on the gums below the incisors) and, more rarely, cattle (e.g. on the tongue, or on the gum as in sheep), as were noted during the 2001 FMD outbreak in the UK. (J3.148.w10, J3.148.w11, J3.148.w12, J3.148.w13, J3.149.w9).

(B47, B58, B100, B207, B209, B211, B210.89.w89, B212, J3.102.w6, J3.148.w10, J3.148.w11, J3.148.w12, J3.148.w13, J3.149.w9, J64.7.w2, W18.Apl01.sib1)

Associated techniques linked from Wildpro

Return to top of page

How to make a definite diagnosis

Making a definitive diagnosis of FMD usually depends on laboratory tests which can identify the virus in material from the animal (e.g. skin from vesicles, fluid from vesicles, blood from animals in the early stages of the disease). In a country which is normally free from FMD and does not use vaccination against FMD, detection of antibodies to the virus in a blood sample could also be used to indicate contact with the virus.

Initial differential diagnosis from other vesicular diseases affecting livestock (swine vesicular disease, vesicular stomatitis, vesicular exanthema) depends on history including the species affected, clinical signs and laboratory tests. Of these four diseases, only vesicular stomatitis affects horses, cattle may be affected by both FMD and vesicular stomatitis, while only pigs are affected by swine vesicular disease and vesicular exanthema. If a vesicular disease is seen in pigs, all four diseases must be suspected until a definitive diagnosis is made.

(In circumstances such that laboratory tests were not available, field diagnosis distinguishing between the four vesicular diseases could be carried out by inoculating horses and cattle with fresh field material. N.B. This must be carried out under biosecure conditions. See: Foot-and-Mouth Disease - Diagnostic Criteria for further details.)

Note: A study found that during the 2001 FMD epidemic in the UK, sensitivity and specificity of clinical diagnosis was found to be high. Some premises with only sheep and goats were detected only later, by serosurveillance; these may have shown few or no clinical signs. (J67.78.w1) However, another study commented that there was no evidence of FMDV virus, FMDV nucleic acid, or antibodies to FMDV, on 23% of samples premises designated as Infected Premises. While some of these may have been false-negatives, due to e.g. inappropriate samples, it is also possible that the true incidence of FMD may have been over-reported. (J3.159.w1)

Definitive diagnosis depends on virus identification

This usually involves detecting the presence of the virus, but on occasion (where samples for virus detection are not available) may be based on the presence of specific antibodies in serum samples (J64.11.w2). 

The OIE's "Manual of Diagnostic Tests and Vaccines for Terrestrial Animals" Part 2 Section 2.1 Chapter 2.1.1 Foot and Mouth Disease"  states: "Diagnosis of FMD is by virus isolation or by the demonstration of FMD viral antigen or nucleic acid in samples of tissue or fluid. Detection of virus-specific antibody can also be used for diagnosis and antibodies to viral nonstructural proteins (NSPs) can be used as indicators of infection, irrespective of vaccination status. " (W31.Sept07.w4)

Samples taken
  • The ideal samples for virus detection are skin/mucous membrane from intact or freshly-ruptured vesicles (blisters) or fluid from intact vesicles.
  • Other samples which can be used include whole blood (contains virus in the early stages of the disease, including before the appearance of vesicles), milk (also contains virus before clinical signs are visible), bits of skin/epithelium from older lesions and samples from the back of the throat (oesophageal/pharyngeal fluid samples). From dead animals, tissue samples may be taken from the heart (particularly in juveniles), and lymph nodes.
  • Throat (oesophageal/pharyngeal fluid) samples are particularly useful for the detection of subclinically infected animals (e.g. sheep).
  • Milking herds which are considered to be "at-risk" based on risk assessments including models indicating possible windborne spread to farms downwind of an infected farm, can be monitored for infection by testing of bulk milk samples. This may allow diagnosis BEFORE any disease is visible in the herd. (J3.87.w1)
  • Blood for serology should be taken from as many individuals as possible.
    • Serology (detection of antibodies) is used for diagnosis if the disease has been in progress for longer than two weeks (B210.89.w89).
  • In sheep in particular, in which infection is often subclinical, blood should be taken for both virus detection and antibody detection. (J64.21.w23)
(B209, B210.89.w89, J3.87.w1, J64.21.w23)
Tests for presence of virus
  • Tests for the presence of virus/viral antigen may be carried out directly on samples (such as skin/mucous membrane from intact or freshly-ruptured vesicles (blisters) or fluid from intact vesicles) which may contain large amounts of virus.
  • N.B. Tests are available which, when performed on fresh material from vesicles (blisters) or vesicular fluids, allow a definitive diagnosis within a few hours if sufficient virus is present. This means a POSITIVE diagnosis may be given very quickly, within about half a day of a suitable sample arriving at the laboratory.
  • If tests are negative, the samples are used to infect cell cultures to increase the amount of virus. If no infection is obvious in the cultured cells, the culture can be used to infect a fresh culture. Only if no virus can be detected after two or three attempts to grow and detect the virus can it be said that the sample was negative. This means that a while a POSITIVE diagnosis is sometimes given very quickly a NEGATIVE diagnosis takes longer to confirm and there is sometimes a delay before a POSITIVE diagnosis can be given.
  • N.B. The speed with which samples could be examined would vary depending on the distance from an appropriate laboratory.
  • In a large outbreak, a very high laboratory capability may be needed to process multiple samples required for both diagnosis and surveillance purposes.
  • Note: Pen-side test kits have been developed which, subject to satisfactory validation, could be used for rapid pen-side testing for FMD virus and minimise the time required for confirmation of the disease.
(J3.87.w1, J3.148.w9, J64.11.w2, J71.144.w1, J217.50.w1, J217.96.w1, P22.2000App18.w1, B58, B209, B210.89.w89, B211, B495.7.w7 -full text provided, D320.App17.w18)
Serological tests for presence of antibodies
  • "The demonstration of specific antibodies to structural proteins in nonvaccinated animals, where a vesicular condition is present, is sufficient for a positive diagnosis." (W31.Sept07.w4)
    • Appropriate tests are the virus neutralisation test or ELISAs.
  • If vaccination has been used, the presence of antibodies to structural proteins of the virus cannot distinguish between animals which have been vaccinated and those which have been infected with live virus.
  • Serological tests for structural antigens are generally serotype-specific. (J3.160.w1, J19.81.w2, W31.Sept07.w4)
Tests for antibodies to non-structural proteins
  • In recent years tests have been developed to detect antibodies to non-structural proteins of FMDV. These tests can distinguish between animals which have been vaccinated but not exposed to the foot-and-mouth disease virus (FMDV), and those which (whether or not they have been vaccinated) have been infected with the virus (J35.167.w2, J69.20S2.w1, J71.142.w1, J71.143.w1, J71.145.w1).
    • "At present [2002] it is accepted that the use of NSP can be used to verify absence of infection in vaccinated cattle on a herd basis." (J64.21.w25)
    • The OIE has accepted that serological tests for non-structural proteins can be used to distinguish between animals which have been infected and those which have been vaccinated and have not been in contact with the virus. (W31.Sept07.w2)
      • "Tests for antibodies to some NSPs of FMD virus are useful in providing evidence of previous or current viral replication in the host, irrespective of vaccination status. " (W31.Sept07.w4)
  • Serological tests for non-structural proteins are not serotype-specific. (J35.167.w2)
  • Antibodies to non-structural proteins develop from about 7-10 days post infection in cattle and pigs but may not be detectable in sheep until 14-22 days (depending on the NSP being tested for). Antibodies to NSP decline earlier after infection than do antibodies to structural proteins (J35.167.w2)
  • While no serological test is 100% sensitive, so some individuals could be NSP-antibody negative despite having been infected, on a herd basis the absence of antibodies to NSP can be accepted as showing that viral activity is not present. The presence of antibodies to NSP provides evidence of exposure to FMD Virus (J35.167.w2).
(B209, J35.167.w2, J64.21.w25, J69.20S2.w1, J70.16.w1, J71.142.w1, J71.143.w1, J71.145.w1, D35.w1, D35.w2, W31.Sept07.w4)
Associated techniques linked from Wildpro

Return to top of page

How to tell if an animal is carrying FMD Virus

Animals are defined as FMD Virus carriers if they still have FMD Virus detectable more than 28 days after infection. However, such animals do not necessarily fit the normal epidemiological definition of a carrier [for diseases in general] as an individual not showing symptoms of disease but able to disseminate infection, since they are not necessarily contagious (J249.91.w2).
  • Syncerus caffer - African buffalo may carry FMD Virus for up to five years; cattle may carry the virus for as long as three years, and sheep and goats for up to nine months. Deer also may develop the carrier state. Pigs have never been recorded to develop the carrier state.
  • If present, the virus is usually found in the oesophageal/pharyngeal area (specifically the tonsillar area in sheep and goats).
Detection of carrier status
  • Samples of fluid and cells from the back of the throat (oesophageal/pharyngeal) are taken and tested for the presence of the virus/virus antigen. If the virus is detected, it confirms that the virus is present in the throat of the animal at that time. The test only detects virus in carriers about 50% of the time, so repeated tests must be carried out to confirm that a single animal in NOT a carrier. Testing of samples from a percentage of animals in a herd or flock can be used to detect whether carriers are present in the herd/flock.
  • Note: There is the possibility that vaccinated animals may occasionally become carriers without developing detectable antibodies to the virus; however used on a herd basis it is possible to distinguish by serological tests for non-structural proteins between vaccinated herds in which the virus has circulated (and in which there might be carriers) and those which have never encountered the virus (in which there cannot be any carriers). (J69.20S2.w1, J70.17.w2, J71.142.w1, J71.143.w1, J71.145.w1)
  • Note: The epidemiological importance of FMDV carrier animals in the spread of this disease is disputed. It is probable that, with the possible exception of Syncerus caffer - African buffalo, transmission of virus from carriers to susceptible animals is a very rare event, and the risk of transmission from a vaccinated carrier "is probably considerably lower and close to zero" (J249.91.w2).

(J3.77.w3, J19.64.w1, J19.66.w1, J19.68.w1, J35.149.w1, J35.158.w1, J42.118.w1, J249.91.w2, B207, B209, B210.89.w89)

Associated techniques linked from Wildpro

Return to top of page

How to tell if FMD Virus is cycling in a population of animals

Foot-and-mouth disease, by its nature as a highly contagious disease, is generally a disease of herds/groups of animals rather than individuals. For this reason, testing of a representative sample of the population should detect the presence of the disease. Care must be taken in the interpretation of test results, for example if serological testing for antibodies shows that all animals in a particular population are positive for the same three strains, the antibodies may be associated with the use of a trivalent vaccine containing those strains of the virus. Of particular use is the detection of antibodies in animals which were previously seronegative, which confirms the continued presence of the disease in the population. In a vaccinated populations, in which the detection of structural antibodies in standard tests cannot distinguish whether animals have been vaccinated or infected, tests which detect antibodies to non-structural proteins of the virus (which will only be present following active multiplication of the virus in the host, not after the use of an inactivated/killed vaccine) are important tools for the detection of previous infection.
Surveillance

Surveillance is the detection of evidence that animals are, or have been infected. It involves clinical examination of animals to detect disease as well as sampling for laboratory testing. In laboratory tests detection of virus/virus antigen indicates that an animal is infected at present (active infection or carrier status), while detection of antibody indicates that an animal has been infected at some time in the past (or has been vaccinated) but not that is necessarily infected at the time the sample was taken.

Routine surveillance measures (e.g. detection and investigation of suspicious disease) should be in place at all times.

During a disease outbreak epidemiological monitoring is important both for tracing the origin of the outbreak and for determining the animals which are likely to be infected. Epidemiological studies in a Foot-and-Mouth Disease outbreak may include tracing back from the first known case in order to try to determine the source of the infection (time, place and original virus source) and tracing forward of animals which may be at risk (using data such as animal, person and vehicle movement records and models of possible airborne spread).

The form of surveillance required will vary depending on the situation and may change considerably during the course of an outbreak and in response to particular events or new information. For example, it has been suggested that following an outbreak of FMD in a large pig unit, models of airborne spread could be used to determine which premises were under the virus plume and at high risk of being infected. Surveillance could then be focused on these farms. It has also been suggested that in such a situation an effective and economical method of early detection of infection in dairy herds would be by testing of bulk milk samples, since virus is shed in milk in sufficient quantities to allow virus detection before clinical signs are seen (J3.87.w1).

Although specific surveillance and laboratory testing is concentrated on animals and premises at the highest risk of infection, it is important during an outbreak of FMD to ensure that all persons involved with livestock play a role in surveillance as the disease may occur in places which have not been forecast as being at high risk (i.e. premises with no known direct or indirect contact with an Infected Premises and not known to be exposed to windborne virus).

In general, surveillance should begin as soon as infection may be detectable following possible exposure to the virus. For FMD this usually means any time from two days after possible exposure, since this is the earliest time at which clinical signs may be seen, although the incubation period (time before clinical signs are seen) may sometimes be much longer (e.g. 14 days or more), for example after exposure to only a low dose of the virus.

Early detection of disease is extremely important to allow rapid initiation of appropriate control measures against this extremely contagious disease.

It is important to ensure that:

  • Sufficient numbers of samples are taken (too few samples may not allow confirmation of negative results as being meaningful).
  • The correct samples are taken, depending on whether detection of antigen or antibody is required. Taking of both samples for antigen detection and samples for antibody detection from the same animal may be useful to avoid duplication of effort or loss of potential data if the test for either antigen or antibody is negative or inconclusive. N.B. once an animal has been culled and the carcass disposed of, it is not possible to repeat-sample to confirm or refute original results.
  • A sufficient quantity of the appropriate tissue or blood is taken to allow the tests to be performed and completed satisfactorily with minimal delay.
  • Samples are correctly labelled with all the information required to maximise the information they can provide (e.g. date, place and identity of the individual animal, vaccination status if appropriate etc.).
  • Samples are handled and transported correctly to ensure that they do not themselves present a means by which the virus can be spread and to ensure that samples reach the laboratory in a state allowing the required tests to be carried out.
  • Samples are processed by an appropriate laboratory, capable of carrying out the required tests.
  • There is sufficient laboratory capacity to handle potentially extremely large numbers of samples during an outbreak.

It is also important to consider what actions should follow detection of disease, e.g.:

  • a "stamping out" policy (including appropriate culling, quarantine and disinfection) if monitoring indicates a limited outbreak;
  • additional limited-area vaccination if sampling and the use of epidemiological models indicate that the rate of disease spread threatens to overwhelm local capabilities for rapid slaughter and disposal of carcasses;
  • emergency mass vaccination if tests show that infection is already widespread or is likely to become widespread in the near future.

On individual premises, surveillance is extremely important following re-stocking, so that recurring disease can be detected at the earliest possible opportunity.

Once an outbreak of FMD has been controlled, additional surveillance is required to confirm which populations have and have not been exposed to the disease. In this situation, detection of antibodies indicating previous infection (non-structural antibodies if vaccination has been practised in the region on either a routine or an emergency basis) is generally required, although sampling for the detection of antigen in carrier animals may also be carried out. Once more, it is necessary to decide what is the objective of surveillance and what action is to be taken depending on the results of surveillance. Depending on the region in which the outbreak has occurred, the pre-outbreak FMD-status (OIE) of the country and the disease control measures which have been used, post-outbreak surveillance may be intended to confirm freedom of the area/national herd from infection (following "stamping out), detect viral activity in a vaccinated population or establish whether or not a vaccination campaign has been effective.

N.B. Ongoing adequate surveillance is a condition of the granting of any type of "FMD-free" status by the OIE for the purposes of international trade and is an important requirement to regain an "FMD-free" status following an outbreak of FMD. Complete documentation is needed if the results of surveillance are to be acceptable internationally as confirming freedom from FMD.

Surveillance of wildlife

Detection of the presence of disease in a wild population may be difficult, particularly if only a small proportion of animals are affected at any one time and/or the disease is not generally fatal.

It is important to consider carefully which animals should be sampled (e.g. samples to be taken from freshly-dead carcasses, sick animals to be culled and sampled or a proportion of apparently healthy animals to be culled for surveillance purposes).

Monitoring of wildlife during an outbreak of FMD may provide important information about the spread of disease. It has been suggested that wild susceptible animals such as deer, because they may move over large areas and come into contact with a variety of premises, may act as sentinels for the presence FMD Virus. This may be particularly important in situations where (a) all livestock in an area have been slaughtered as part of disease control operations, so that there are no domestic animals left to act as sentinels or (b) all susceptible domestic livestock have been vaccinated so that it is only in wild animals that clinical disease is likely to be detected.

Additionally, information about the disease status of wildlife populations may be required for decision-making for disease control: control of FMD by "stamping out" without vaccination is unlikely to be effective if there is a continuing reservoir of virus circulating in an infected wildlife population.

(J3.87.w1, J69.20S2.w1, J71.145.w1, B127, P5.40S.w3, W18.Apl01.sib1, V.w23).

Associated techniques linked from Wildpro

Return to top of page

Authors & Referees

Authors Dr Debra Bourne MA VetMB PhD MRCVS
Referee Suzanne I Boardman BVMS MRCVS

Return to top of page