43. Foot and mouth disease (diagnosis, differential diagnosis, prevention, control).

Question 1

Diagnosis: Clinical signs?

Answer 1

Diagnosis: clinical signs

• Fever + salivating + lame + vesicles- Suspect FMD!
• Notifiable disease - veterinary administration rules
• Sampling: 1 g of vesicular wall and fluid, OP fluid, saliva (swab, probang) > buffered transport
• medium (pH 7.2-7.6) > refrigerated or iced > submit ASAP!

Question 2

Direct virus detection?

Answer 2

Direct virus detection

• virus or parts of virus, clinical phase:
• Virus isolation on cell culture: 48 hr later CPE or blind passage
• ELISA: Ag detection, indirect sandwich
• Complement fixation: Ag detection
• RT-PCR, qRT-PCR, sequencing: nucleic acid detection

Question 3

Indirect virus detection?

Answer 3

Indirect virus detection:

• Ab - recovered or vaccinated animals
• VNT, ELISA

Question 4

Differential diagnosis?

Answer 4

Differential diagnosis:

• Bo: pox, BVD, IBR, bluetongue (no ulceration), malignant catarrhal fever (more respiratory
• signs, nasal discharges and not salivation)
• Ov, Cap: ovine parapox, capripox, bluetongue (no ulceration)
• Sus: SVD, VES, vesicular stomatitis

Question 5

Treatment?

Answer 5

Treatment:

• Europe (FMD free-don’t vax)
• Endemic regions - hyperimmune serum, clean environment, soft litter and feed, gentle milking,
• treatment of lesions

Question 6

Prevention?

Answer 6

Prevention:

• FMD free countries: control measures, restriction of movement (early recognition, culling, disposal,
• cleaning and disinfection), protection zones (3 km), surveillance zones (10 km),slaughterhouses
• Endemic areas: movement restriction, vaccination
• Ban on all live animals and raw products of animal origin from infected countries, preventive rules,
• proper state veterinary services and diagnostic laboratory network, contingency plan, exercise from
• time to time, vaccine reserves (deep frozen raw virus)

Question 7

Vaccines?

Answer 7

Vaccines:

• even if vaccinated,
• can still get the infection,
• ONLY protected from clinical signs
• Bo: inactivated, aluminium-gel absorbed, mono-, bi-, trivalent, protection for 6-12 months,
• 2X/year,
• then 1X/year
• Sus:
• inactivated,
• oil adjuvated,
• protection for 3-6 months

Question 8

Public health Humans moderately susceptible?

Answer 8

Public health: humans - moderately susceptible

• Rare, work-related cases (lab, contact with animals, epidemic control)
• seroconversion without clinical signs
• Mild fever, general symptoms, vesicles at nails and oral mucosa, benign
• Diagnostic: direct/indirect virological methods, full recovery
• Prevention: protective clothing, pasteurized milk
• UK 2001: Heddon-on-the-Wall, Northumberland, swine - over 6 million animals killed
• UK 2007: virus escaped from laboratory, control measures were successful