Surveillance and the Early Detection of Foot and Mouth Disease

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Surveillance and the Early Detection of Foot
and Mouth Disease

• Melissa McLaws DVM PhD Candidate, Dept of
  Population Medicine, University of Guelph
• Carl Ribble DVM, MSc, PhD Advisor
• Craig Stephen DVM, PhD Member of advisory
  committee
• Bruce McNab DVM, PhD Member of advisory
  committee

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Foot and Mouth Disease (FMD)

• Highly contagious disease of cloven-hoofed
  animals (including cattle, sheep, pigs)
• Re-emerging disease?
• Large outbreaks of disease have recently occurred
  in areas that had been free of disease for a long
  time (UK, Taiwan)
• High profile
• Concern as agent of bio-terrorism

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From FAO website
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FMD Epidemiology

• Infection by inhalation or ingestion of the virus
• Spread on farm
• direct contact, mechanical
• Spread between farms
• animal movements, fomites
• (people,vehicles, wildlife)
• Wind-borne transmission (spread esp. by pigs,
  cattle esp. susceptible)

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FMD Clinical Signs

• Fever, depression, milk-drop
• Lameness
• Salivation
• Vesicles in mouth, coronary band, teats
• Ruptured vesicles/- secondary infection
• Sudden death young animals
• Species differences (maybe subtle and transient
  in sheep/goats)

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FMD Diagnosis

• Currently, case identification is dependent on
  recognition of clinical signs (rather than
  screening with a lab test)
• Non-endemic situation passive surveillance
• Epidemic (and endemic) situation- active and
  passive surveillance

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Non-Endemic Situation
HIGH RISK PERIOD
Disease circulating in endemic area
Introduction to non-endemic area
Detection of disease in non-endemic area
Control Procedures
Time
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Non-endemic Situation

• Identified outbreaks of FMD in countries where
  the disease is not endemic from 1992-2002
• Literature review
• Little information about how the outbreaks were
  found
• Identify and describe factors that contributed to
  the final epidemic size

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(No Transcript)
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Taiwan 1997
UK 2001 Uruguay 2001
Yugoslavia 1996 Greece 1994
Infected Premises
Italy 1993
Greece 1996
Netherlands 2001 Brazil 2000
S. Korea 2000 2002 Greece 2000
Japan 2000 S. Africa 2000 Swaziland 2000
Botswana 2002 2003 France 2001 Ireland 2001
Uruguay 2000 Argentina 2000 Bulgaria 1993
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Discussion

• Most incursions of FMD virus lead to a relatively
  small outbreak, but on 3 occasions there was a
  big one WHY?
• Late detection?
• Animal movement?
• Virulent strain?
• Animal density?

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Relationship Between Epidemic Size and Time to
Report
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Time since previous outbreak
Education
Veterinary Infrastructure
Awareness
Time from Infection to Detection
Livestock demographics (density, type, husbandry)
Unrestricted Animal Movement
Level of Viral Shedding
EPIDEMIC SIZE
Species Affected
Control - Methods and Effectiveness
Viral Strain