Foot-and-Mouth Disease Foot-and-Mouth Disease

Texas A&M University Texas A&M University College of Veterinary MedicineCollege of Veterinary Medicine

Jeffrey MusserJeffrey Musser DVM, PhD, DABVPDVM, PhD, DABVP

Suzanne Burnham, DVMSuzanne Burnham, DVM

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Foot-and-mouth DiseaseFoot-and-mouth Disease

Disease BasicsDisease Basics

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Foot-and-mouth DiseaseFoot-and-mouth DiseaseContentsContents

Definition and EtiologyDefinition and Etiology

Host rangeHost range

Incubation Incubation

Clinical signsClinical signs

TransmissionTransmission

Diagnosis Diagnosis

Differential DiagnosisDifferential Diagnosis

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Foot-and-mouth DiseaseFoot-and-mouth Disease

Known around the world asKnown around the world as

Afta epizotica Afta epizotica

Bek-en-klouseer Bek-en-klouseer

Fiebre AftosaFiebre Aftosa

Fievre aphteuse Fievre aphteuse

Maul-und-KlauenseucheMaul-und-Klauenseuche

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Foot-and-Mouth DiseaseFoot-and-Mouth Disease Foot-and-mouth Foot-and-mouth disease is a highly disease is a highly contagious, viral contagious, viral disease of domestic disease of domestic cloven-hoofed and cloven-hoofed and many wild animals many wild animals characterized by characterized by erosions in the erosions in the mucosa of the mouth mucosa of the mouth and hooves.and hooves. Image courtesy of Dr Tom McKenna

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

This devastating disease is considered to This devastating disease is considered to be the most important livestock disease in be the most important livestock disease in the world.the world.

It is It is THETHE most contagious virus disease of most contagious virus disease of animals.animals.

It has not occurred in the US since 1929.It has not occurred in the US since 1929.

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Worldwide Occurrence of Worldwide Occurrence of FMDFMD

Worldwide Occurrence of Worldwide Occurrence of FMDFMD

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Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Countries that are foot-Countries that are foot-and-mouth disease-free and-mouth disease-free do do NOTNOT want to re-import want to re-import the diseasethe disease

FMD free countries have FMD free countries have instituted embargoes on instituted embargoes on agricultural imports from agricultural imports from countries where effective countries where effective control is not practicedcontrol is not practiced

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Important factorsImportant factors

Short incubation periodShort incubation period

Release of virus prior to appearance Release of virus prior to appearance of clinical signsof clinical signs

Massive quantities of virus releasedMassive quantities of virus released

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Extended survival in the environmentExtended survival in the environment

Multitude of routes of virus transmissionMultitude of routes of virus transmission

Minimal size of the infective doseMinimal size of the infective dose

Aerosol transmission possible up to 250 Aerosol transmission possible up to 250 km depending on strain and km depending on strain and

environmental conditions (10km, environmental conditions (10km, 170km, 250km reported over water)170km, 250km reported over water)

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Foot-and-Mouth DiseaseFoot-and-Mouth Disease Although not very lethal to Although not very lethal to adult animals, it causes adult animals, it causes serious production losses.serious production losses.

FMD is a major FMD is a major constraint to international constraint to international trade in livestock and trade in livestock and livestock productslivestock products

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Foot-and-mouth Disease:Foot-and-mouth Disease:

EtiologyEtiology

Host rangeHost range

Incubation Incubation

Clinical signsClinical signs

TransmissionTransmission

Diagnosis Diagnosis

Differential DiagnosisDifferential Diagnosis

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

EtiologyEtiology

The virion is non-enveloped, small,The virion is non-enveloped, small,(about 23-25 nm in (about 23-25 nm in Diameter), and hasDiameter), and has icosahedral symmetry. icosahedral symmetry. It is composed of a It is composed of a single-stranded RNA single-stranded RNA genome of about 8,000genome of about 8,000nucleotides.nucleotides.

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

EtiologyEtiologyFoot-and-mouth Disease virus (FMDV)Foot-and-mouth Disease virus (FMDV)

FamilyFamily Picornaviridae,Picornaviridae, genusgenus Aphthovirus Aphthovirus

7 serological types: 7 serological types: – Type A Type A – Type O, Type O, – Type C, Type C, – South African Territories (SAT) 1, South African Territories (SAT) 1, – South African Territories (SAT) 2, South African Territories (SAT) 2, – South African Territories (SAT) 3, South African Territories (SAT) 3, – and Asia 1and Asia 1

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

EtiologyEtiologyFoot-and-mouth Disease virus (FMDV)Foot-and-mouth Disease virus (FMDV)

Over 60 subtypesOver 60 subtypes

Antigenic variation seems Antigenic variation seems

to be greatest for Serotype A.to be greatest for Serotype A.

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Foot-and-mouth Disease: Foot-and-mouth Disease:

EtiologyEtiology

Host rangeHost range

Incubation Incubation

Clinical signsClinical signs

TransmissionTransmission

Diagnosis Diagnosis

Differential DiagnosisDifferential Diagnosis

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Host RangeHost Range

All cloven-hoofed All cloven-hoofed domestic animalsdomestic animals::

Cattle and BuffaloCattle and BuffaloSheep Sheep GoatsGoatsSwineSwine

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Host RangeHost Range

Most cloven-footed Most cloven-footed wild animalswild animals::

Deer Deer Bison Bison Feral hogsFeral hogsAntelopeAntelope

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Host RangeHost Range

Water buffalo Water buffalo can be carriers forcan be carriers for5 years5 years

Llamas and alpacasLlamas and alpacasare susceptible, butare susceptible, but

of no epidemiologicalof no epidemiologicalsignificancesignificance

African water buffalo

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

GiraffesGiraffes

ElephantsElephants

Host RangeHost Range

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Host RangeHost Range

ArmadillosArmadillosArmadillos are not only Armadillos are not only susceptible but are susceptible but are capable of transmitting the capable of transmitting the disease to each other and disease to each other and possibly to other speciespossibly to other species

USAHA Proceedings 1974:USAHA Proceedings 1974:““Clinical and serological response of the Nine-banded armadillo (Dasypus Clinical and serological response of the Nine-banded armadillo (Dasypus novemcinctus) to viruses of African Swine Fever, Hog Cholera, Rinderpest novemcinctus) to viruses of African Swine Fever, Hog Cholera, Rinderpest Vesicular Exanthema of Swine, Vesicular Stomatitis and Foot-and-mouth Vesicular Exanthema of Swine, Vesicular Stomatitis and Foot-and-mouth disease”disease”

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Host RangeHost Range

HedgehogsHedgehogs

NutriaNutria

CapybarasCapybaras

Rats, Mice andRats, Mice andGuinea pigs can Guinea pigs can be infected be infected experimentallyexperimentally Capybara

http://www.hedweb.com/animimag/capybara.htm

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Host RangeHost RangeNot seen in odd-toedNot seen in odd-toedanimals such as animals such as horses, zebras or rhinoshorses, zebras or rhinos

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Old World CamelOld World Camelis resistant to is resistant to natural infectionnatural infection

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Host RangeHost Range

indicatormaintena

nce

amplifier

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Foot-and-mouth Disease: Foot-and-mouth Disease:

EtiologyEtiology

Host rangeHost range

Incubation Incubation

Clinical signsClinical signs

TransmissionTransmission

Diagnosis Diagnosis

Differential DiagnosisDifferential Diagnosis

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

IncubationIncubation

Incubation period depends on which strain of Incubation period depends on which strain of FMD virus (7 serotypes), dosage, FMD virus (7 serotypes), dosage,

and the route of entry.and the route of entry.

As short as As short as 2-3 days2-3 days in close contact in close contact

As long as As long as 10-14 days10-14 days from windborne infection

Experimentally shown to be as short as 18-24 Experimentally shown to be as short as 18-24 hours hours

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Minimum doses of FMD virus to Minimum doses of FMD virus to initiate infectioninitiate infection

RespiratoryRespiratory OralOral

Route RouteRoute Route

CattleCattle 1212 TCID50 1X 10 1X 106 6 TCID50

PigsPigs 2020 TCID50 8X 108X 1033TCID50

SheepSheep 10 10 TCID50

ImpalasImpalas 11 TCID50

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

PathogenesisPathogenesis

Most animals acquire virus usually by Most animals acquire virus usually by inhalationinhalation

Humans and pigs are more susceptible to Humans and pigs are more susceptible to infection by oral routeinfection by oral route

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Initial replication Initial replication in terminal in terminal bronchioles, 24hpibronchioles, 24hpi

Subsequent Subsequent viremia with viremia with spread to stratified spread to stratified squamous squamous epitheliumepithelium

H&E

ISH

PathogenesisPathogenesis

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Cytolytic replication in stratum Cytolytic replication in stratum spinosum cells, creating vesiclespinosum cells, creating vesicle

ISHISHH&EH&E

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Foot-and-mouth blisters on a pig's snout

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

24 hrs after infection, virus begins 24 hrs after infection, virus begins replicatingreplicating

Virus is excreted in high quantities in Virus is excreted in high quantities in expired air, in all secretions including expired air, in all secretions including milk, and from ruptured vesicles.milk, and from ruptured vesicles.

Pigs can excrete up to 400 million Pigs can excrete up to 400 million infective virus particles a dayinfective virus particles a day

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Excretion of FMD virus can begin up Excretion of FMD virus can begin up to 14 days BEFORE clinical disease to 14 days BEFORE clinical disease becomes apparent. becomes apparent.

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

PathogenesisPathogenesis

Virus replication in respiratory epithelium Virus replication in respiratory epithelium and lymphoid tissueand lymphoid tissue

In domestic ruminants pharynx and dorsal In domestic ruminants pharynx and dorsal soft palate are predilection site for soft palate are predilection site for replication of FMDvreplication of FMDv

Virus persists there for prolonged periodsVirus persists there for prolonged periods

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Replication in lymphoid tissue, tonsils Replication in lymphoid tissue, tonsils mucosa of soft palatemucosa of soft palate

Virus can be recovered from Virus can be recovered from retropharyngeal, mandibular, and parotid retropharyngeal, mandibular, and parotid lymph nodes in more than 50% of cattle in lymph nodes in more than 50% of cattle in pre-viremic stagepre-viremic stage

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

High virus levels may occur in organs and High virus levels may occur in organs and tissues which do not generally develop tissues which do not generally develop gross changes including unaffected skin gross changes including unaffected skin areasareas

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Characteristic Blister FormationCharacteristic Blister Formation

Epithelial lesions of FMD are initiated by Epithelial lesions of FMD are initiated by infection of single cells in the stratum infection of single cells in the stratum spinosum. spinosum.

Following infection, bullae develop by lysis Following infection, bullae develop by lysis of cell swollen by degeneration and of cell swollen by degeneration and release of intracellular fluid or focal release of intracellular fluid or focal intercellular edemaintercellular edema

Bullae coalesce and ruptureBullae coalesce and rupture

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Characteristic Blister FormationCharacteristic Blister Formation

Development of characteristic vesicular Development of characteristic vesicular lesions depends on 2 factors: lesions depends on 2 factors:

– Infection of epitheliumInfection of epithelium

– Persistent local irritation or frictionPersistent local irritation or friction

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

This explains why the mouth, feet and This explains why the mouth, feet and teats are predilections sites for blisters teats are predilections sites for blisters in cattle; in cattle;

the dorsum of the snout in pigs from the dorsum of the snout in pigs from snuffling, snuffling,

on the knees of warthogs that kneel on the knees of warthogs that kneel when feedingwhen feeding

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Foot-and-mouth Disease: Foot-and-mouth Disease:

EtiologyEtiology

Host rangeHost range

Incubation Incubation

Clinical signsClinical signs

TransmissionTransmission

Diagnosis Diagnosis

Differential DiagnosisDifferential Diagnosis

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

General Clinical SignsGeneral Clinical Signs

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

General Clinical SignsGeneral Clinical Signs

Vesicles and erosions in the mucosa of the Vesicles and erosions in the mucosa of the mouth, and skin-hoof junctionmouth, and skin-hoof junction

Excessive salivationExcessive salivation

LamenessLameness

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

General Clinical SignsGeneral Clinical Signs

ListlessListless

Lifting feet alternatelyLifting feet alternately

Lameness Lameness

Clear nasal discharge Clear nasal discharge progressing to progressing to mucopurulent mucopurulent

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

General Clinical SignsGeneral Clinical Signs

Blisters in the mouthBlisters in the mouth

Blisters on the muzzleBlisters on the muzzle

Blisters on the tongueBlisters on the tongue

Excessive SalivationExcessive Salivation

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Signs develop rapidly in cattle and Signs develop rapidly in cattle and are more severe than lesions in pigs, are more severe than lesions in pigs, sheep or goats.sheep or goats.

If all species are exposed together, If all species are exposed together, cattle will show signs first. cattle will show signs first.

Some serotypes of FMDV affect Some serotypes of FMDV affect particular species more than others.particular species more than others.

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Clinical Signs in CattleClinical Signs in Cattle

Fever (103Fever (103°°-106-106°F)°F)

DepressionDepression

AnorexiaAnorexia

Milk production Milk production ceasesceases

Blisters start to form Blisters start to form in the mouth in the mouth

Excessive ropy, Excessive ropy, viscous salivationviscous salivation

Blisters rupture within Blisters rupture within 24 hrs leaving raw, 24 hrs leaving raw, painful ulcerspainful ulcers

Mouth lesions usually Mouth lesions usually heal in 10 - 14 daysheal in 10 - 14 days

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Clinical Signs in CattleClinical Signs in Cattle

Feet Inter-digital space

Coronary band

Teats

Blisters form on: Mouth Tongue Dental pad Gums Soft palate

MuzzleNostrils

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Clinical Signs in CattleClinical Signs in Cattle

Body tremors from Body tremors from painpain

Lameness from Lameness from developing lesions developing lesions on feeton feet

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Clinical Signs in CattleClinical Signs in Cattle

Lameness

•Coronary band lesion first appears blanched•Blisters form between the digits•Stamping and shaking of feet•Trembling

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Clinical Signs in CattleClinical Signs in Cattle

Smacking of the lips Smacking of the lips and sucking of the and sucking of the sore tongue is sore tongue is characteristiccharacteristic

Secondary Bacterial Secondary Bacterial infectionsinfections

Mastitis –permanent Mastitis –permanent damage to udderdamage to udder

Pregnant cows may Pregnant cows may abortabort

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Progression of diseaseProgression of disease

Blisters at infection site initially appear as Blisters at infection site initially appear as blanched area in the epitheliumblanched area in the epithelium

Area fills with serous fluid forming a Area fills with serous fluid forming a vesiclevesicle

Vesicles enlarge and coalesceVesicles enlarge and coalesce

Vesicles crack or rupture leaking fluidVesicles crack or rupture leaking fluid

The epithelium necroses off leaving raw The epithelium necroses off leaving raw ulcer or erosionulcer or erosion

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Progression of diseaseProgression of disease

Grey fibrinous coating forms over lesionsGrey fibrinous coating forms over lesions

The coating becomes discolored, yellow, The coating becomes discolored, yellow, brown, greenbrown, green

As epithelium is restored, lines of As epithelium is restored, lines of demarcation are evidentdemarcation are evident

Sometimes but not always, permanent Sometimes but not always, permanent scars formscars form

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Progression of diseaseProgression of disease

When blisters are present, cattle salivate When blisters are present, cattle salivate profusely with ropy viscous material profusely with ropy viscous material hanging from mouthhanging from mouth

Also see severe lacrimation and nasal Also see severe lacrimation and nasal dischargedischarge

When vesicles rupture, fever ends When vesicles rupture, fever ends followed by end of viremiafollowed by end of viremia

Start to finish, signs last 15-30 days.Start to finish, signs last 15-30 days.

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Progression of diseaseProgression of disease

Recovered animals are permanently Recovered animals are permanently unthriftyunthrifty

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Aging lesions in cattleAging lesions in cattle

Day One

Formation of fluid-filled blister, or vesicle 2 mm-10 cm on the dorsal surface of the tongue

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Aging lesions in cattleAging lesions in cattle

Day Day FourFour

Day Day SixSix

Salivation increases as vesicles form and rupture. Symptoms increase in intensity.

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Aging lesions in cattleAging lesions in cattle

Lines of demarcation

Days 8-14Days 8-14

Animals may recover in 2 weeks. Only 1-5% die from FMD

High morbidity, Low mortality

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

FMD – Brazil, Argentina, Uruguay.

2000

Clinical Signs in CattleClinical Signs in Cattle

Morbidity approaches 100% in a Morbidity approaches 100% in a susceptible herd. susceptible herd.

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Clinical Signs in CattleClinical Signs in Cattle

Low MortalityLow MortalityRarely fatal except in young animalsRarely fatal except in young animals

Extra-epithelial replication limited to myocardium, immature animals only

USDAUSDA

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Clinical Signs in CattleClinical Signs in Cattle

Young calves may die Young calves may die without showing any without showing any clinical signsclinical signs

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

In young animals there is focal necrosis In young animals there is focal necrosis of cardiac muscle. “Tiger heart”of cardiac muscle. “Tiger heart”

50-80% 50-80% youngyoung animals die (calves, lambs, etc) animals die (calves, lambs, etc)USDAUSDAUSDAUSDA

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

RecoveryRecovery

Recovered animals are “poor doers”Recovered animals are “poor doers”

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

“More than 200 cows infected in Cambodian foot-and-mouth disease outbreak”

Time is GMT + 8 hours

Posted: 25-Jul-2005 12:19 hrs A cow stands on a bank of the Tonle Sap River. More than 200 cattle in Cambodia have been infected with foot-and-mouth disease since an outbreak last month northwest of the capital, but have since recovered. http://www.todayonline.com/articles/63247.asp

Recovery

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Up to 50% of recovered Up to 50% of recovered

ruminants continue ruminants continue

to shed the virus sporadically, to shed the virus sporadically,

6-24 months post-infection.6-24 months post-infection.

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Water buffalo can be carriers for 5 yearsWater buffalo can be carriers for 5 years

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Clinical Signs in SwineClinical Signs in SwineFeverFeverNo appetiteNo appetite

Reluctant to moveReluctant to moveWorst blistering is Worst blistering is on the feeton the feetMay slough the May slough the hoofhoof

AbortionAbortionSuckling piglets die Suckling piglets die suddenly – even suddenly – even before blisters before blisters developdevelop

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Clinical Signs in SwineClinical Signs in Swine

Mastitis Mastitis Blisters on teats and udders

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Clinical Signs in SwineClinical Signs in Swine

Pigs –Reluctance to move, painful toes

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Clinical Signs in Sheep and Clinical Signs in Sheep and GoatsGoats

•Vesicles on dental pad and between toes•Prone to develop secondary foot-rot•Lamb death, 50-90%•Sheep can be carriers for up to 9 months

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Clinical Signs in Sheep and GoatsClinical Signs in Sheep and Goats

When sheep or goats become infected with FMD, the disease may notnot be diagnosed for a considerable time because the clinical signs may be very mild.

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Sheep may appear healthy but will be producing infectious aerosols or spreading the virus via urine, feces or direct contact.

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Lesions in giraffeLesions in giraffe

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Foot-and-mouth Disease: Foot-and-mouth Disease:

EtiologyEtiology

Host rangeHost range

Incubation Incubation

Clinical signsClinical signs

TransmissionTransmission

Diagnosis Diagnosis

Differential DiagnosisDifferential Diagnosis

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

TransmissionTransmissionAerosols/Airborne, Inhaled Aerosols/Airborne, Inhaled

Direct or indirect contact-droplets, Direct or indirect contact-droplets,

IngestionIngestion

Artificial InseminationArtificial Insemination

Vectors (vehicles, equipment, or humans)Vectors (vehicles, equipment, or humans)

Carrier stateCarrier state

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

TransmissionTransmission

AerosolSpread of aerosols from infected animals, given the right temperature and humidity can travel 250km on the wind

Aerosols transmission via dust storms in Africa spread FMD to England

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

TransmissionTransmission

Airborne on the windAirborne on the wind

Airborne from burning Airborne from burning pyres suspectedpyres suspected

Airborne from infected Airborne from infected milk transportmilk transport

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

TransmissionTransmission

Sheds 400,000,000 virus particles per day

Aerosol droplets spread from infected animal

Only takes 10-12 virus particles to infect one cow

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

TransmissionTransmission

Direct or indirect contact with infected animals

If infected feral hogs come into contact with domestic livestock in the US, it will affect the whole world!

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

TransmissionTransmission

Foot and mouth disease Foot and mouth disease virus can be transmitted virus can be transmitted via: via:

Milk Milk Semen Semen Saliva Saliva FecesFeces UrineUrine BreathBreath

“Supersoaker fights on the dairy farm”

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

TransmissionTransmission

Ingestion- Feeding contaminated garbage (meat, milk, glands, bones, cheese, etc)

Intraocular

Artificial insemination, or natural reproduction

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Vectors

Contact with contaminated objects (equipment, footwear, clothing)

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Transmission by humansTransmission by humans

A person in contact with infected animals may retain and exhale virus for up to 36 hours and serve as source of infection.

Humans serve as a mechanical vector when moving from infected animals to susceptible animals.

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

TransmissionTransmission

Birds can be mechanical vectors and can pass Birds can be mechanical vectors and can pass viable FMD virus after ingestion, but are not viable FMD virus after ingestion, but are not considered a factor in the spread of the diseaseconsidered a factor in the spread of the disease

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Birds can also be infected with FMD virus and shed virus in feces

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Courtesy Maryland Dept of Agriculture Public Affairs

www.skysailing.com/ images/nzcropduster.jpg

Intentional act ofBioterrorism

Effective if humidity is>60%

Can travel 60km overland or 300km over water

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Foot-and-mouth Disease: Foot-and-mouth Disease:

EtiologyEtiology

Host rangeHost range

Incubation Incubation

Clinical signsClinical signs

TransmissionTransmission

Diagnosis Diagnosis

Differential DiagnosisDifferential Diagnosis

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

DiagnosisDiagnosis

Serum neutralization testSerum neutralization test

Complement fixation testComplement fixation test

Enzyme-linked immunosorbent assayEnzyme-linked immunosorbent assay

Field diagnosisField diagnosis

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

FMD TestingFMD Testing

TissuesVesic. Fluid

ProbangSwab

Virus isolationVirus isolation>> 7days 7days

RT-PCRRT-PCR6 hr6 hr

Realtime PCRRealtime PCR2 hr2 hr

Virus ID

Electron Microscopy

TissuesVF

Ag-ELISAAg-ELISA5 hr5 hr

CF-AgCF-Ag3hr3hr

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Laboratory DiagnosisLaboratory Diagnosis

For virusFor virus For antibodiesFor antibodies

ELISAELISA Virus Virus neutralizationneutralization

Virus isolationVirus isolation Agar gel Agar gel immunodiffusionimmunodiffusion

PCR*PCR*

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Foot-and-mouth Disease: Foot-and-mouth Disease:

EtiologyEtiology

Host rangeHost range

Incubation Incubation

Clinical signsClinical signs

TransmissionTransmission

Diagnosis Diagnosis

Differential DiagnosisDifferential Diagnosis

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Differential DiagnosisDifferential Diagnosis

As a vesicular type disease:As a vesicular type disease:– Vesicular stomatitis, Vesicular stomatitis, – swine vesicular disease of pigs, swine vesicular disease of pigs, – vesicular exanthema of pigsvesicular exanthema of pigs

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Differential DiagnosisDifferential Diagnosis

Based on ulcerative lesions in the mouth Based on ulcerative lesions in the mouth or on the muzzle:or on the muzzle:– BVD/MDBVD/MD– MCFMCF– Bluetongue and other orbivirusesBluetongue and other orbiviruses– LSDLSD– IBRIBR– RinderpestRinderpest

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Differential DiagnosisDifferential Diagnosis

Based on foot lesions:Based on foot lesions:– DermatophilosisDermatophilosis– Foot-rotFoot-rot– MCFMCF

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Differential DiagnosisDifferential Diagnosis

Vesicular StomatitisVesicular Stomatitis

Bovine MammilitisBovine Mammilitis

Bovine Viral DiarrheaBovine Viral Diarrhea

Bovine Papular StomatitisBovine Papular Stomatitis

Mucosal Disease (foot Mucosal Disease (foot lesions)lesions)

Infectious Bovine Infectious Bovine RhinotracheitisRhinotracheitis

RinderpestRinderpest

Bluetongue (foot lesions)Bluetongue (foot lesions)

Peste des Petits Peste des Petits RuminantsRuminants

Foot RotFoot Rot

Chemical IrritantsChemical Irritants

Swine Vesicular DiseaseSwine Vesicular Disease

Vesicular Exanthema - Vesicular Exanthema - swineswine

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

FMD or VS?FMD or VS?

CannotCannotdistinguishdistinguishclinicallyclinically

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

FMD vs VSFMD vs VS

VS is not as contagious as FMD VS is not as contagious as FMD FMD does not affect horsesFMD does not affect horsesVS - Domestic animals are probably not primary VS - Domestic animals are probably not primary hosts.hosts.VS - Vector-borne disease.VS - Vector-borne disease.

VS - No effective vaccines available in US.VS - No effective vaccines available in US.

VS - Requires specific ecological conditions.VS - Requires specific ecological conditions.

VS - Infects large number of wild species.VS - Infects large number of wild species.Both are zoonotic diseases Both are zoonotic diseases

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Rapid spread of foot-and-mouth disease world-wide….

FMD Type O 1990

FMD Type O 1994

FMD Type O 1997

FMD Type O 1999

FMD Type O 2000

FMD Type O 2001

Foot-and-Mouth DiseaseDistribution and Recent Activity

Present

Recent Activity

Free

1999 2000 2001(Rev. 5-05-01)

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Images AcknowledgementImages Acknowledgement

Capybaras: David Pearce, BLTC Research, Capybaras: David Pearce, BLTC Research, http://www.hedweb.com/animimag/capybahttp://www.hedweb.com/animimag/capybara.htm accessed 8/22/06ra.htm accessed 8/22/06..

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Image Watermark Image Watermark

““KAW” images by Dr. Ken A. WaldrupKAW” images by Dr. Ken A. Waldrup

““MvanVuuren” images used with MvanVuuren” images used with permission by Dr. Moritz van Vuurenpermission by Dr. Moritz van Vuuren

““LLogan” images by Dr. Linda LoganLLogan” images by Dr. Linda Logan

““Suz” images by Dr Suzanne BurnhamSuz” images by Dr Suzanne Burnham

““USDA” images by staff at PIADCUSDA” images by staff at PIADC

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

BibliographyBibliography

Committee on Foreign Animal Diseases of the United States Animal Committee on Foreign Animal Diseases of the United States Animal Heath Association, “Foreign Animal Diseases” 1992, Ch. Vesicular Heath Association, “Foreign Animal Diseases” 1992, Ch. Vesicular Diseases, p. 368-382.Diseases, p. 368-382.

W. A. Geering, et.al, Exotic Diseases of Animals: a field guide for W. A. Geering, et.al, Exotic Diseases of Animals: a field guide for Australian veterinarians, 1995, Ch Foot-and-mouth disease, p.112-Australian veterinarians, 1995, Ch Foot-and-mouth disease, p.112-131131

Ninth Edition of Merck Veterinary ManualNinth Edition of Merck Veterinary ManualM. Van Vuuren, Foot-and-mouth Disease, an Overview, University of M. Van Vuuren, Foot-and-mouth Disease, an Overview, University of

Pretoria 2005, Presentation given at Knoxville, Tenn. FEAD course.Pretoria 2005, Presentation given at Knoxville, Tenn. FEAD course.Thomson, G. R. and Bastos, A. D. S. “Foot-and-mouth disease” Ch 125 Thomson, G. R. and Bastos, A. D. S. “Foot-and-mouth disease” Ch 125

of Infectious Diseases of Livestock, Volume 2. Ed. J. A. W. Coetzer of Infectious Diseases of Livestock, Volume 2. Ed. J. A. W. Coetzer and R. C. Tustin. Oxford University Press, second edition, 2004, and R. C. Tustin. Oxford University Press, second edition, 2004, 1324-1365.1324-1365.

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

BibliographyBibliography

Tomasula, P.M. and R.P. Konstance. “The Survival of Foot-and-Mouth Tomasula, P.M. and R.P. Konstance. “The Survival of Foot-and-Mouth Disease Virus in Raw and Pasteurized Milk and Milk Products”.Disease Virus in Raw and Pasteurized Milk and Milk Products”. Journal of Dairy Science, Journal of Dairy Science, 2004; 87:1115-1121. 2004; 87:1115-1121.

Callis, J.J. et al. “Foot-and-mouth Disease – A Review”. Callis, J.J. et al. “Foot-and-mouth Disease – A Review”. JAVMA,JAVMA, 1968; 1968; 153:12, 1798-1802.153:12, 1798-1802.

Musser, J.M.B. “A practitioner’s primer on foot-and-mouth disease”. Musser, J.M.B. “A practitioner’s primer on foot-and-mouth disease”. JAVMA, JAVMA, 2004; 224:8, 1261-1268.2004; 224:8, 1261-1268.

Alexandersen, S., et al. “The Pathogenesis and Diagnosis of Foot-and-Alexandersen, S., et al. “The Pathogenesis and Diagnosis of Foot-and-Mouth Disease”. Mouth Disease”. J. Comp. Path. J. Comp. Path. 2003; 129:1-36.2003; 129:1-36.

O.I.E.O.I.E.

USDA, APHIS, VS, The Grey Book. And associated websites.USDA, APHIS, VS, The Grey Book. And associated websites.

Personal interviews with Dr Logan, Dr McKenna, Dr Coetzer, Dr Personal interviews with Dr Logan, Dr McKenna, Dr Coetzer, Dr VanVuuren and Dr WaldrupVanVuuren and Dr Waldrup

Foot-and-Mouth DiseaseFoot-and-Mouth Disease

Foot-and-mouth DiseaseFoot-and-mouth Disease

AcknowledgementsAcknowledgementsSpecial thanks to Special thanks to Linda Logan, DVM PhDLinda Logan, DVM PhDKen Waldrup, DVM PhDKen Waldrup, DVM PhDJeffrey Musser, DVMJeffrey Musser, DVMProfessor Moritz van VuurenProfessor Moritz van VuurenKelsey Pohler- Research AssistantKelsey Pohler- Research AssistantCharles Swanson - Dairy Science studentCharles Swanson - Dairy Science studentJoe Stevens – Dairy Science studentJoe Stevens – Dairy Science studentTom McKenna, DVM PhDTom McKenna, DVM PhDCorrie Brown, DVM PhDCorrie Brown, DVM PhD