Emerging Diseases:The Past and Future - Dr. Robert Desrosiers, Boehringer Ingelheim, from 2015 Summer Swine Health Seminar, August 22, 2015, Wrightsville Beach, North Carolina, USA. More presentations at http://www.swinecast.com/2015-boehringer-ingelheim-carolina-swine-health-seminar

1. Robert Desrosiers
North Carolina Health Seminar
August 21, 2015

2. Introduction
3 parts
Part 1: Transmission
Part 2: The past
Part 3: The future

3. Part 1: Transmission

4. Direct vs indirect
Direct contact → most important
Left source herd infected
Reality often different
Indirect transmission XXXX frequent

5. Pathogen Number of cases Indirect
transmission
FMD
(Gibbens, 2001)
1847 95%
CSF
(Elbers, 1999)
429 97%
PRRS
(Desrosiers, 2004)
44 100%
MH
(Desrosiers, 2004)
18 100%
PED in Quebec 9 89%

6. Transmission: Two types of pathogens
Mainly direct
Mange
Progressive atrophic rhinitis (PAR)
Swine dysentery (SD)
2) Frequently indirect
MH
PRRS
FMD

7. How to determine?
Remain negative in
Hog dense
Many herds infected
History tells us possible
Mange, PAR & SD
Quebec, 1979
Virtually disappeared

8. US situation
∼ Quebec, mange & PAR
SD, more cases late vs early 2000s
August 2014, 8 US practitioners
6 ≠ issue
1 minor
1 significant

9. Swine Dysentery
Animals & basic biosecurity (transport)
Difficulty determine status
Serological test
Low %
Duff, 2014
5 infected farms, 150 sows
0%, 0%, 0.67%, 0.67% and 1.33%

10. Danish SPF system (Desrosiers, 2011)
Year Swine
Dysentery
Atrophic
rhinitis
Mycoplasma
hyopneu.
PRRSV
2004-2005 4 7 171 269
2005-2006 7 4 161 297
2006-2007 11 8 163 235
2007-2008 0 5 196 305
2008-2009 3 6 160 226
Average 5 6 170.2 266.4

11. Hypothetical classification (?)
More easily indirectly = collective
approach
Individual appoach = Mange, PAR & SD
Individual approach ≠ MH, PRRS & FMD
MH in Switzerland, Finland & Norway

12. Pathogens easily indirectly
Collective approach
Existing, emerging or reportable
Centralized entity
If not government
Quebec EQSP ∼ $150,000
US National Swine Health Inf Center

13. ‘Insanity is doing the same thing over
and over again and expecting different
results.’

14. 0
5
10
15
20
25
30
35
40
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
%

15. # PRRS abortion diagnoses ISU
(Madson, personal communication, 2015)

17. SHMP – August 14, 2015
1,2 million sows, PRRS cumulative incidence
July 1 to June 30
2009-2010 29%
2010-2011 35%
2011-2012 42%
2012-2013 29%
2013-2014 23%
2014-2015 25%

18. Importance of time
Collective control program
Immediately; before first case
Quebec, every week
∼ 20,000 market hogs From Ontario
∼ 12,000 pigs From Ontario
∼ 1,000-1500 sows To Ontario &
US
Efforts before 1st PED case

19. Conclusions for Part 1
Today, many pathogens → indirect
↑ easily indirectly → ↓ individual efforts
Collective approach, coordinated
True for existing, emerging, reportable
Countries got rid of FMD, HC, PRV

20. Part 2: The past

21. Quotes
Bohr
‘Prediction is very difficult, especially about
the future.’
Desrosiers
‘If you don’t look behind, your behind may
suffer.’

22. Learn from the past
4 pathogens - 40 years
APP, PRRS, PCV2 & PED
2 questions
How infected?
Avoid infection, reduce spread?
PRRS & PED

23. How infected with APP?
1st report 1957 UK → 1959 US
Late 70s (Canada & US)
Don’t know
From UK or elsewhere?
Already here?
Present ∼ 20 years before

24. How infected with PRRS?
NA, Mystery Swine Disease → 1987
Ontario
1979 2/51
1982 10/56
US
Late 70s
Present before, evolved, became problem

25. How infected with PCV2?
Clark & Harding, 1996
Canada (Magar, 2000)
1985 sows 13.6%
1989 sows 72.4%
Two waves
PCV2a Present before, evolved
PCV2b From Europe (Vidigal,

26. How infected with PED?
China, major losses late 2010, new genotype
US, April 16, 2013
China, but don’t know
Canada, Jan 22, 2014 SDPP

27. Avoid infection, reduce spread of
PRRS?
Avoid infection
Not much
Reduce spread
5 years Prevention
20 years Aerosol transmission

28. PRRS – Can we get rid of it?
Chili, Sweden, Switzerland
US → $664 millions ($15 billions)
Nothing wrong reconsidering
How?
Collective, global approach
Elimination field strains first
Then decide on vaccines

29. Avoid infection, reduce spread of PED?
Avoid infection
Canada, no US SDPP (Ontario & PEI →
Quebec)
US, no import from China, but
Reduce spread
US → > 50%
Canada → < 2%
Quebec → 0.15% & no PDC

30. PED: Quebec vs US
Quebec US
Central entity at time
of first case
Yes No
Was initial source of
infection identified
Yes No
Were few herds
initially infected
Yes No
Diagnostic test at
time of first case
Yes No
Start testing before
first case
Yes No

31. Quebec vs US
Quebec
Benefited XXX from US & Ontario research
Some, before first Quebec case
Efforts triggered proximity
≠ thousands kms away
If Canada first…

32. Conclusions for Part 2
Emerging present way before → difficult
Prevention strategy ≠ great
Don’t know how any, or why
Have not gotten rid of any (APP, PCV2)
Adding diseases without
PED → Canada so far

33. Part 3: The future

34. Emerging: 4 different
categories
1) Known pathogens not here
2) Known pathogens, here, get worse
3) Harmless organisms, not here, become pathogens
4) Harmless organisms, here, become pathogens

35. 1) Known pathogens not here
PED
3 ways
Stop introducing
Continue, but make sure (products & processes)
Sterilize products
Diagnostic test available 1st case or before
Mandatory reporting to central entity
Closed herds (All 4 categories pathogens)

36. 2) Known pathogens, here, get worse
SIV
H1N1 from 1930s to 1980s; then 1998
Huge potential impact
Disease in pigs vs humans (pH1N1)
Surveillance, but control plan if?

37. 3) Harmless organisms, not here,
become pathogens
Harmless organism, foreign country, introduced
here & become pathogens
Costly retrospective studies
2 ways
Forbid introduction
Sterilize products

38. 4) Harmless organisms, here, become
pathogens
PRRS
Rapidly
Realize & identify
Develop diagnostic & apply control
Even best scenario, months or years
≠ prevent emergence
Can we reduce diffusion?

39. Multiple site system (?)
≥ 90%
↑↑↑ geographic spread (states or countries)
Davies, 2012
Minnesota
∼10,000 pigs /day
> 30 states & Canada
If new bug in the US (humans)

41. Multiple site system (?)
↑↑↑ transmission opportunities
Quebec → 9/10 PED → 1 transport
Weaning 2 or 3 times/week 104 or 156
days
Gilt introductions, culled removals, nursery to
finishers, market hogs to slaughter
∼ 150 to > 200 days

42. Consider hypothetical alternative
FF on one site, 4 week batch farrowing
Closed herd
Empty finishing units 1 day
Culled animals same day
13 days (MS with WTF = 13 + 13)

43. Reasons
FF operation → Multiple site
Maintain health
Difficult to eliminate
Others

44. Examples of FF → Healthy
(Paboeuf F, personal comunication, 2014)
Ploufragan, populated 1979
25 sows, research
HEPA filters, heated feed, etc.
No antibiotics
∼ no mortality
After 36 years, negative most swine pathogens
SIV & PCV2

46. Size of sow herds
Early 90s, 369 herds ∼ 400 sows
Goede 2014, 2.1 million sows ∼ 2,700
sows
In 20 years ∼ 18,000 sows
Larger herds more likely to
Become infected
Infect other

47. Size of sow herds
Wei, 2014 pH1N1 9 passages
Norway (50-80 vs 18,000 sows)
12 years SIV-free
∼ Salmonella-free
∼ lowest ABC
Harding, IPVS 2014 → Sustainability

48. Sustainability
1. Producers, decent living
2. Consistently, safe/healthy food
3. Minimal antibiotics
4. High consideration welfare
5. Least negative environmental impact
6. Reduce contamination/spread pathogens
7. Economically get rid pathogens
8. Reduce risk harmless organisms →
pathogens
9. Reduce risk swine bugs → humans

49. Sustainability
Basis for discussion
Experts: veterinarians, physicians, economists,
welfare specialists, environmentalists, producers,
packers, retailers, consumers
∼ 75% emerging human diseases are zoonotic
Define which points, grade

50. 8 veterinarians – Vast experience
No pigs in the US
110,000,000 pigs
Optimal production system vs sustainability
Consideration 9 points

51. 8 questions
1. Which system
2. How ‘clean’ animals
1. A. suis, H. parasuis, S. suis, M. hyosynoviae,
M. hyorhinis
3. Size sow herd
4. How frequently wean
5. AI-AO by room, building, site
6. Closed herd
7. Minimal distance
8. Other comments

52. Questions Answers
What system 6/8, Multi, wean-finish
How ‘clean’ animals 7/8 ‘cleaner’
Size sow herd 1,200 to 5,000
How frequently wean Twice/week to 4 weeks
AI-AO, room, building, site 5/7 by site
Closed herd 5/8
Minimal distance 1.6 to 50 km
Other comments Many

53. Start with sow herd - New
Well located/protected → Laws/directives
‘Cleaner’ animals
More robust animals
Nielsen, 2006
∼1,000 pigs/boar 2% vs 10%
Closed, batch farrowing
Wean-to-finish, AI-AO by site
Still weaknesses

54. Start with sow herd - Existing
Increase cost-effectiveness air filtration
HEPA vs current
Consider other ways
EPI → ↓ SIV & PRRS
Mass vaccination → 4 vs 21 & 6 vs 36d
Filtering exhaust air, etc.
Once aerosol taken care of
Consider depopulation, cleaner, more robust

55. Réseau Cristal
(Marchand D, personal communication, 2014)
Depopulation/repopulation SPF
10 years
2 years before vs 2 years after
Pregnant females
∼ $21/pig
∼ 2 years
1/3 antibiotic-free
↓ 16.8Kg CO2 eq

56. North America is vulnerable
2 or 3 PED strains, porcine deltacoronavirus,
mutant PCV2
Asia (China)
China
PRV, CSF, FMD, Japanese encephalitis
ASF, Highly Virulent AIV
FMD revenue losses (10 years) → $57 billion

57. We, also, are a danger!
Singh Brar, 2014
PRRS North America → China (Mid 90s)
US PED → South Korea & Taiwan (Late 2013)
US PED → Canada (Early 2014)
Not only vulnerable, making others vulnerable

58. Time to reconsider

59. Summary comments
1) NA - Persistent vulnerability
2) Will be more – Already here
3) ↓ diffusion - Reconsider
4) Indirect transmission – Collective approach (or)
5) LT sustainability vs ST profitability