1. Foot-and-Mouth Disease Attack on the Midwest U. S.

2. Purpose
To develop and evaluate a plausible scenario for an attack on the Midwest United States using Foot-and-Mouth disease virus.
The scenario is designed to facilitate discussions on broad agricultural preparedness and response issues
To develop and evaluate a plausible scenario

3. Foot-and-Mouth Disease
Foot-and-mouth disease (FMD) is an extremely contagious, viral disease of domestic cloven-hoofed and many wild animals, characterized by fever, vesicular lesions and, subsequent erosions of the epithelium of the mouth, tongue, nares, muzzle, feet, and teats.
Definition:
If have one infected or exposed animal in a herd, can expect all animals in herd to develop disease within few days.
Extremely contagious – the most contagious disease we know –moves like wildfire through herd.
Viral – caused by a virus
Cloven hoof – two toed domestic animals – cattle, sheep, goats, pigs. Wildlife – affects two-toed animals bison, deer, antelope. Some other wild animals such as elephants could be affected by some of the strains in Asia.

4. Availability of FMD Virus
FMD Virus is easily obtained in many countries of the world
Distribution and Recent Activity
Present
Recent Activity
Free
1999
2000
2001
(Rev. 3 - 27
01)

5. FMD Virus Stability pH Sensitive: <6.5 or >11.0
UV Sensitive: (sun light)
Survives in moist, organic-rich materials
It is important to understand virus stability to understand what happens to contamination on the farm and beyond.
Virus very sensitive to pH – either low pH or high –below 6.5 or higher than 11.
Disinfectants that have a low pH such as ordinary vinegar or acetic acid can inactivate virus. Alkaline solutions also good. Approved list is available.
Sunlight can inactivate virus quickly.
If have bedding or feed that has been contaminated and circumstances are cool and moist such as inside a barn in winter, virus can last a long time even weeks or months. Depends on weather and conditions.

6. FMD Transmission Aerosols Direct contact Meat products Fomites
1. Aerosols. Transmission for the most part is by aerosols. Infection is in lungs, when animals exhale it is sent airborne in large amounts, especially with pigs. Estimated that for each liter of air that a pig exhales, there is enough virus to infect 10,000 pigs. Farm with a lot of pigs – form a cloud of virus – cloud can move with the wind. When have low temperature, high humidity and lack of sunlight virus can move from farm to farm.
Direct contact of animal-to-animal.
Meat Products. Virus is in all organs of body. Does not survive in meat because change in pH is in muscle, but it will survive in bone marrow and internal organs. Risky – sausage where organs are included with meat. If sausage is contaminated and leftovers are fed to pigs, pigs can get FMD.
Fomites. Inanimate objects such as barn, cars, boots which can carry virus farm to farm. Biosecurity/animal health precautions needed.

7. FMD - Epidemiology Morbidity: >95% Mortality:
Adults <1%
Neonates >50%
Carrier state: in cattle (6-24 months)
Morbidity
Close to 100% of animals on a farm will be affected.
Mortality
Less than 1% of animals will die, but they will be less productive than they were. Doubtful that dairy cows will produce milk. Economic losses for producers are tremendous.
In young animals between 50 to 100% will die. Calves 50%; lambs 60-70%; piglets 100%.
Carrier State
If recover, carry virus in throat for up to two years. Even if vaccinated, could carry virus. Vaccination prevents clinical manifestation, but still could carry.
If, for example, we would vaccinate, would have to mark cattle so they are not in national herd, otherwise have potential to circulate virus.

8. FMD- Cattle Tongue Lesions
Tongue in cattle most dramatic for lesions.
Bumps form first, then blisters.
Blisters fuse together – oval and white.
When this whole blister breaks –a sheet of epithelium falls off, and leaves raw bleeding tongue that is extremely painful, and animal cannot eat. To help animal, water/feed are placed under its head.

9. FMD – Swine Feet & Snout Lesions
Pigs are “factory” of the virus. Exhale a lot of virus. Pigs have visible lesions.
Foot lesions so painful that pigs walk on knuckles and squeal.
Blisters on snout.

10. APHIS Response
Goal: To detect, control and eradicate the disease agent as quickly as possible to return the United States to free status
The scope of the disaster will vary by the speed of the response
Multiple foci
Real time exponential growth

11. Risk Factors for Spread of FMD
Animal density
Animal concentration points
Livestock movements
Livestock markets
Sale Barns
Fairs and shows
People movements
Wildlife
Climate

12. Population at Risk

13. Model Assumptions Limited to one location
11 days from exposure to detection
For 60 day period
Limited livestock movement
No climatic factors
No wildlife spread
No people spread

14. Introduction of FMD
Single foreign operative introduces FMD virus into a single cattle herd in the United States Midwest

16. Day 1
Total = 13 Farms Affected

17. Quarantined States

18. National Activities
Movement controls (temporary) animals in transit continue to destination, no further movements allowed
Intensive surveillance
National and international communications

19. Zones of Control Infected zone Surveillance zone
Quarantined area around the infected or presumed infected premises, (10km – 6mi as starting point)
May be alter based on weather, terrain, wildlife, livestock concentrations, etc
Surveillance zone
Restricted area around the infected zone
May initially include the entire affected state and those in close proximity to infected zone
Will be modified pending tracing and surveillance results

20. Infected Zone Activities
Intensive epidemiological investigations of farmed animals and wildlife
Perimeter movement controls of roads
Animals or animal products stopped
Conveyances and people decontaminated
Depopulation and decontamination of infected farms

21. Surveillance Zone Activities
Case finding
Livestock concentration points
Sick calls
Awareness campaign
Tracing contacts with infected animals and premises
We presume 8 contacts per farm per week
Livestock, vehicles, people and materials
Vaccination of a buffer zone around infected farms if efficacious

22. Appraisal – Depopulation - Disposal
Appraise affected animals and dispose of them as close to the affected premises as possible – within hours of culling
Estimated requirements are 5 workers per herd of 40 animals per day for depopulation and disposal
Average herd size = 200 animals

23. Decontamination of Premises
Thorough cleaning and disinfecting of facilities, products and equipment
3 people per farm per day for each 40 animals in herd

24. Day 5 All
Total = 64 Affected Farms

25. Day 25
Total = 3091 Affected Farms

26. Day 60
Total = 5844 Affected Farms

27. Analysis
Scenario suggested a single operative infecting a single farm but multiple farms would be more likely and could effectively spread FMD nationwide
Computer model showed that with the single introduction there would be 5844 affected farms within 60 days

28. Analysis 200 animals on each farm $350 to appraise each farm
$5.50 euthanasia for each animal
$325 indemnity for each animal
$15 to dispose of each animal
$8,000 to clean and disinfect each farm
$3,200 further surveillance cost from each affected premises

29. Analysis Appraise $ 2.04M Euthanasia $ 6.43M Indemnity $379.86M
Disposal $ 17.53M
Clean/Disinfect $ 46.75M
Surveillance $ M
Total for ONE incident $471.32M

30. Analysis Export Losses with our markets closed Live Animals Germplasm
Animal Feed
Human Food
Animal Byproducts
$Millions?? $Billions??