Robert Desrosiers

North Carolina Health SeminarAugust 21, 2015

Introduction

3 parts

Part 1: Transmission

Part 2: The past

Part 3: The future

Part 1: Transmission

Direct vs indirect

Direct contact most importantLeft source herd infected

Reality often differentIndirect transmission XXXX frequent

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%

Transmission: Two types of pathogens

Mainly directMangeProgressive atrophic rhinitis (PAR)Swine dysentery (SD)

2) Frequently indirectMHPRRSFMD

How to determine?Remain negative in

Hog dense Many herds infected

History tells us possibleMange, PAR & SD

Quebec, 1979Virtually disappeared

US situation Quebec, mange & PAR

SD, more cases late vs early 2000s

August 2014, 8 US practitioners6 issue1 minor1 significant

Swine DysenteryAnimals & basic biosecurity (transport)

Difficulty determine statusSerological testLow %

Duff, 20145 infected farms, 150 sows0%, 0%, 0.67%, 0.67% and 1.33%

Danish SPF system (Desrosiers, 2011)

Year SwineDysentery

Atrophic rhinitis

Mycoplasmahyopneu.

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

Hypothetical classification (?)

More easily indirectly = collective approach

Individual appoach = Mange, PAR & SD

Individual approach MH, PRRS & FMD

MH in Switzerland, Finland & Norway

Pathogens easily indirectlyCollective approach

Existing, emerging or reportableCentralized entity

If not governmentQuebec EQSP $150,000US National Swine Health Inf

Center

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

05

10152025303540

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

%

# PRRS abortion diagnoses ISU

(Madson, personal communication, 2015)

SHMP – August 14, 20151,2 million sows, PRRS cumulative

incidenceJuly 1 to June 302009-2010 29%2010-2011 35%2011-2012 42%2012-2013 29%2013-2014 23%2014-2015 25%

Importance of timeCollective 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

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

Part 2: The past

Quotes

Bohr‘Prediction is very difficult, especially

about the future.’

Desrosiers‘If you don’t look behind, your behind

may suffer.’

Learn from the past4 pathogens - 40 years

APP, PRRS, PCV2 & PED

2 questionsHow infected?Avoid infection, reduce spread?

PRRS & PED

How infected with APP?1st report 1957 UK 1959 US

Late 70s (Canada & US)

Don’t knowFrom UK or elsewhere?Already here?

Present 20 years before

How infected with PRRS?NA, Mystery Swine Disease 1987

Ontario1979 2/51 1982 10/56

USLate 70s

Present before, evolved, became problem

How infected with PCV2?Clark & Harding, 1996

Canada (Magar, 2000)1985 sows13.6%1989 sows72.4%

Two wavesPCV2a Present before, evolvedPCV2b From Europe (Vidigal, 2012)

How infected with PED?

China, major losses late 2010, new genotype

US, April 16, 2013China, but don’t know

Canada, Jan 22, 2014 SDPP

Avoid infection, reduce spread of PRRS?

Avoid infectionNot much

Reduce spread5 years Prevention20 years Aerosol transmission

PRRS – Can we get rid of it?Chili, Sweden, SwitzerlandUS $664 millions ($15 billions)Nothing wrong reconsidering

How?Collective, global approachElimination field strains firstThen decide on vaccines

Avoid infection, reduce spread of PED?

Avoid infectionCanada, no US SDPP (Ontario & PEI

Quebec)US, no import from China, but

Reduce spreadUS > 50%Canada < 2%Quebec 0.15% & no PDC

PED: Quebec vs USQuebec 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

Quebec vs USQuebec

Benefited XXX from US & Ontario research

Some, before first Quebec caseEfforts triggered proximity

thousands kms away

If Canada first…

Conclusions for Part 2Emerging present way before difficult

Prevention strategy greatDon’t know how any, or why Have not gotten rid of any (APP, PCV2)

Adding diseases without

PED Canada so far

Part 3: The future

Emerging: 4 different categories1) Known pathogens not here

2) Known pathogens, here, get worse

3) Harmless organisms, not here, become pathogens

4) Harmless organisms, here, become pathogens

1) Known pathogens not herePED3 ways

Stop introducingContinue, but make sure (products &

processes)Sterilize products

Diagnostic test available 1st case or beforeMandatory reporting to central entity

Closed herds (All 4 categories pathogens)

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?

3) Harmless organisms, not here, become pathogens

Harmless organism, foreign country, introduced here & become pathogens

Costly retrospective studies

2 waysForbid introductionSterilize products

4) Harmless organisms, here, become pathogensPRRSRapidly

Realize & identifyDevelop diagnostic & apply control

Even best scenario, months or years prevent emergence

Can we reduce diffusion?

Multiple site system (?) 90% geographic spread (states or countries)

Davies, 2012Minnesota10,000 pigs /day> 30 states & Canada

If new bug in the US (humans)

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

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)

Reasons

FF operation Multiple site

Maintain health

Difficult to eliminate

Others

Examples of FF Healthy(Paboeuf F, personal comunication, 2014)

Ploufragan, populated 1979

25 sows, researchHEPA filters, heated feed, etc.No antibiotics no mortalityAfter 36 years, negative most swine

pathogensSIV & PCV2

Size of sow herdsEarly 90s, 369 herds 400 sowsGoede 2014, 2.1 million sows 2,700 sowsIn 20 years 18,000 sows

Larger herds more likely toBecome infected Infect other

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

Sustainability1. Producers, decent living2. Consistently, safe/healthy food3. Minimal antibiotics4. High consideration welfare5. Least negative environmental impact6. Reduce contamination/spread pathogens7. Economically get rid pathogens8. Reduce risk harmless organisms

pathogens9. Reduce risk swine bugs humans

SustainabilityBasis for discussion

Experts: veterinarians, physicians, economists, welfare specialists, environmentalists, producers, packers, retailers, consumers

75% emerging human diseases are zoonotic

Define which points, grade

8 veterinarians – Vast experience

No pigs in the US

110,000,000 pigs

Optimal production system vs sustainability

Consideration 9 points

8 questions1. Which system2. How ‘clean’ animals

1. A. suis, H. parasuis, S. suis, M. hyosynoviae, M. hyorhinis

3. Size sow herd4. How frequently wean5. AI-AO by room, building, site6. Closed herd7. Minimal distance8. Other comments

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

Start with sow herd - NewWell located/protected

Laws/directives‘Cleaner’ animalsMore robust animals

Nielsen, 20061,000 pigs/boar 2% vs 10%

Closed, batch farrowingWean-to-finish, AI-AO by site

Still weaknesses

Start with sow herd - ExistingIncrease cost-effectiveness air filtration

HEPA vs current

Consider other waysEPI SIV & PRRSMass vaccination 4 vs 21 & 6 vs 36d Filtering exhaust air, etc.

Once aerosol taken care ofConsider depopulation, cleaner, more robust

Réseau Cristal (Marchand D, personal communication, 2014)

Depopulation/repopulation SPF10 years2 years before vs 2 years afterPregnant females $21/pig 2 years

1/3 antibiotic-free 16.8Kg CO2 eq

North America is vulnerable2 or 3 PED strains, porcine deltacoronavirus,

mutant PCV2Asia (China)

ChinaPRV, CSF, FMD, Japanese encephalitisASF, Highly Virulent AIV

FMD revenue losses (10 years) $57 billion

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

Time to reconsider

Summary comments1) NA - Persistent vulnerability

2) Will be more – Already here

3) diffusion - Reconsider

4) Indirect transmission – Collective approach (or)

5) LT sustainability vs ST profitability