WPX – Pork Academy – Des Moines, IA (06/06/2013)
Food/Pork Safety Analysis
Marcos H. Rostagno, DVM, MPVM, PhD
USDA-ARS
West Lafayette, Indiana
Contemporary Challenges
in Animal Agriculture
• Food Security
• Food Safety
• Animal Welfare
• Environmental Impact
Food Security
Global Food Demand
1970s – 1990s:  50%
2000s
 60-70%
2050
Options:
 Productivity (Technology)
 Area/land
United Nations, FAO (2009)
Combination of both
 $$$ =  Consumption
Global Production Increase
from 2001 to 2011
Total Global Production
(2011)
50
45
43.7
Percentage Increase
40
Beef  56.8 M ton
Poultry  81.0 M ton
Pork  101.1 M ton
35
30
25
20
18.1
15
10
5
7.9
0
Beef
Pork
Poultry
Pork has been
the meat product
most consumed and
produced, since 1979!
USDA (2011)
Agricultural illiteracy
Technology rejection
Safe
Affordable
Nutritious
(56.87%)
Priorities driving consumer food choices
(Center for Food Integrity, 2012)
Environment
Welfare
(35.01%)
Productivity
Profitability
(8.12%)
Availability + Safety of the food supply
Food Safety Issues:
 Chemical hazards
 Physical hazards
Quality assurance
 Biological hazards
. Pathogens
. Antimicrobial Resistance
Complex challenges
On-farm (pre-harvest) focus
Pork Safety - Biological Hazards
(Pathogens)
Bacterial Pathogens:
Salmonella enterica
Campylobacter coli
Listeria monocytogenes
Yersinia enterocolitica
Parasites:
Taenia solium
Trichinella spiralis
Toxoplasma gondii
Emerging Pathogens:
Methicillin-resistant Staphylococcus aureus
Clostridium difficile
Hepatitis E virus
Caliciviruses
Noroviruses
Scallan et al. (2011)
According to USDA-ERS
$2.3 billion (in 1998 U$)
Medical costs and productivity losses
Frenzen et al.(1999)
Incidence of foodborne pathogens in the U.S.
30
Incidence per 100,000
25
20
Salmonella
15
Campylobacter
E. coli O157
10
5
2012
2011
2010
2009
2008
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
0
Healthy People 2010
Salmonella (6.8)
Campylobacter (12.3)
E. coli O157 (1.0)
Source: www.cdc.gov/foodnet/data/reports.html
Salmonella: a food safety priority for the pork industry!
Attribution: Pork products  5-30% Human salmonellosis
US (6-9%)
EU (15-25%)
Infected pigs (“carriers”)
Salmonella prevalence + levels in the GIT
(Determinants of the pork safety risk)
Salmonella contamination of pork occurs within abattoirs
(Harvest and processing line)
Berends et al.(1996):
Infected pig  Harvest line = 3 - 4x risk of Salmonella-contaminated carcass
Positive Salmonella tests in the PR/HACCP verification
testing program from 1998 to 2011
(Market hogs - All sizes)
10
9
8.7
8
Percent Positive Tests
7
6
5
4.3
3.7
4
4
3.3
3.1
2.8
3
2.6
2.3
2.4
2009
2010
2
1
0
Baseline 1998-2003
2004
2005
2006
2007
2008
www.fsis.usda.gov
2011
From Pig to Pork
Salmonella Prevalence and Levels in the GI tract
Farm
Transport
Lairage
Harvest &
Processing
Salmonella enterica prevalence:
First pull versus close out groups of market pigs
100
90
Prevalence (%)
80
31.3%
P<0.05
70
60
50
40
30
First Pull
9.2%
P<0.05
Close Out
20
10
0
Bacteriology
43/405 (10.6%, 95%C.I. 6.03–15.2%)
vs.
80/405 (19.8%, 95%C.I. 11.3–28.2%)
Serology
85/450 (18.9%, 95%C.I. 12.7–25.1%)
vs.
226/450 (50.2%, 95%C.I. 12.7–25.1%)
Rostagno et al. (2009)
Effect of transport and lairage
on Salmonella prevalence
Prevalence (%)
(Field Study)
a,b,c: P<0.05
Rostagno & Richert (2010)
Salmonella levels in market-weight pigs
subjected to feed withdrawal and/or transport
Log10 CFU/g of sample
5
b
4.5
b
4
3.5
3
a
a
a
a
b
a
2.5
2
a
1.5
a
a
a
1
0.5
0
Ileum
Ctr: Control
FW: Feed Withdrawal (12 h)
T: Transport (2 h)
FWT: Feed Withdrawal + Transport
Cecum
Rectum
a,b: P<0.05
Rostagno et al. (2012)
Effect of stress on the susceptibility
of market-age pigs to Salmonella
(Transport and/or mixing)
c
b
b,c
b
a
a
a
a
a,b,c: P<0.05
C = Control
M = Mixing w/ unfamiliar pig (6 h)
T = Transport (1 h)
T+M = Transport + Mixing
a,b: P<0.05
Rostagno & Lay (in preparation)
www.fsis.usda.gov
What???
Pork Safety - Biological Hazards
(Antimicrobial Resistance)
Antimicrobial Resistance: Food Animals  Humans
Phillips et al.(2004)
Potential Routes of Antimicrobial Resistance
Transmission From Pigs to Humans
Residues
Resistant Pathogens
Resistant Commensals
Environmental
Contamination
USDA – NARMS (2010)
CDC – NARMS (2010)
CDC – NARMS (2010)
“Alternative” Pork Production Systems
Assumption: Happy Pigs = Safe Pork
“Alternative” Production Systems
Key changes:
 Housing facilities/conditions
 Management practices
Effects on
ecology and epidemiology
of pathogens
???
“All Natural”
“Free-Range”
“Organic”

Outdoor access
Foodborne (bacterial) Pathogens
 Limited data available
 No clear pattern (Conventional x Alternative)
However…
Proportion of Salmonella and Campylobacter isolates recovered
from pigs originating from indoor and outdoor production systems
Pathogen
Salmonella*
Campylobacter**
Location
Sample source
Indoor
Outdoor
Farm
Feces
99.6%
0.4%
Slaughter
Carcass pre-evisceration
10.4%
89.6%
Slaughter
Carcass post-evisceration
14.1%
85.9%
Slaughter
Carcass post-chill
37.5%
62.5%
Farm
Feces
55.7%
44.3%
Slaughter
Carcass pre-evisceration
9.4%
90.6%
Slaughter
Carcass post-evisceration
44.2%
55.8%
Slaughter
Carcass post-chill
0%
100%
Adapted from Gebreyes et al. (2005)** and Thakur et al. (2007)*.
Antimicrobial Resistance
Tadesse et al. (2011)
Quintana-Hayashi & Thakur (2012)
Biological Hazards: Pathogens
Parasites
Trichinella spiralis
Toxoplasma gondii
Taenia solium
Occurrence of helminths in different types of pork production systems
Helminth
Outdoor*
Indoor (Extensive)**
Indoor (Intensive)***
Ascaris
+
+
+
Oesophagostomum
+
+
(+)
Trichuris
+
+
(+)
Strongyloides
+
+
Hyostrongylus
+
(+)
Metastrongylus
+
Stephanurus
(+)
Ascarops
(+)
Physocephalus
(+)
Macracanthorhynchus
(+)
Trichinella
(+)
Taenia
(+)
Schistosoma
(+)
Fasciola
(+)
Dicrocoelium
(+)
(+)
(+)
Adapted from Nansen and Roepstorff (1999)
Toxoplasma gondii in the U.S.
Reference
Davies et al.(1998)
Wang et al. (2002)
Gebreyes et al. (2008)
Production Stage
Free-range
Prevalence
19%
Total confinement
0.01%
Sows (Not confined)
20.2%
Sows (Confined)
11.6%
Market hogs (Not confined)
4.4%
Market hogs (Confined)
2.3%
Outdoor
6.8%
Indoor
1.1%
Pork-associated outbreaks???
Oh, yeah!
I’m safe!!!
Complexity = Risk of Unintended Consequences
Does the pork industry have a problem???
Yes!
But, it’s not about safety!!!
Where does the consumer get
information from???
The (mis)information era!!!
“Super Bugs”
“Super Bacteria”
“Antibiotic Apocalypse”
“Factory Farm”
The world is changing…
SCIENCE
(Facts & Data)
CONSUMER
(Perception)
Consumer education is urgently needed!!!
“Given the central role
that food plays in
human welfare and
national stability, it is
shocking – not to
mention short-sighted
and potentially
dangerous – how little
money is spent on
agricultural research.”
Bill Gates
Acknowledgements
USDA-ARS Scientists
Purdue University Faculty
Gary Nowling
Rita Lockeridge
Lots of Students!!!
Thank you!!!