www.mpi.govt.nz • 1 www.mpi.govt.nz
The Campylobacter control
programme in New Zealand
Prof. Steve Hathaway
www.mpi.govt.nz • 2
MPI Campylobacter team
• Steve Hathaway and Peter van der Logt: Science and risk
assessment
• Judi Lee and Sharon Wagener: Standard development
• Gail Duncan: National microbiological database
• Sonja Taege and Catherine Sheerin: Verification
• Sharon Wagener and others: Compliance Response Team
• Craig Thornley: Public health
• Nigel French and Petra Muellner: Source attribution
www.mpi.govt.nz • 3
Campylobacteriosis in New Zealand
(all causes) at start of control programme
0
2,000
4,000
6,000
8,000
10,000
12,000
14,000
16,000
80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06
Year
No
tifi
ca
tio
ns
0
200
400
600
800
1,000
1,200
Ho
sp
ita
lisa
tio
ns
Notifications
Hospitalisations
Cases
= 380 / 100,000 pop.
www.mpi.govt.nz • 4
Campylobacter Risk Management Strategy
2007 -
• Source attribution studies
• Operational research for effectiveness of different interventions e.g.
freezing, and data gaps e.g. risk factors at farm level
• Develop Biosecurity Manual (growing farms)
• New code of practice for primary and secondary processing
• Establish National Microbiological Database (NMD) and test
different methodologies an monitoring strategies
• Review HACCP-based Risk Management Plans at premises level
• Establish five-year public health goal and reporting
• Develop regulatory performance target and response
• Develop risk assessment models to inform decision-making
www.mpi.govt.nz • 5
Development of the NMD
• 2007: Caecal sampling and carcass sampling;
proposal for mandatory target rather than
mandatory interventions (good performers
should not be penalised!)
• 2008: Performance target with escalating
(regulated) responses
• 2009: Caecal sampling ceases as limited value
• 2013: Revised performance target
www.mpi.govt.nz • 6
Testing programme
• Accredited laboratories
• Trained samplers
• Approved methods
• Regulator can see all premises’ results
• Each premises can only see own results
• Quarterly ranking and reporting
www.mpi.govt.nz • 7
Microbiological performance target
Represents an approximate one log reduction in level of hazard
control cf. 2007 national 80th percentile baseline (4.08 to 3.08 logs)
System accredited and verified by MPI
Moving window, high count limit and quarterly limit
Moving window failure when seven or more out of 45 samples from
three successive processing periods are greater than 3.78 log 10
cfu/carcass
Low throughput premises
Integrated industry and regulator response in case of non-
compliance, with possible escalation to premises closure
www.mpi.govt.nz • 8
Subsequent changes to target
• Moving window failures have effectively managed poor
performers Kept
• Hardly any failures against high count (> 5.88 log10 /
rinsate) or quarterly limits Removed
• Mandatory responses too restrictive:
– amended to be more flexible
– increased reporting
• Compliance Response Team visits very effective Kept
www.mpi.govt.nz • 9
Source attribution
www.mpi.govt.nz • 10
Approaches to attribution
• Analytical epidemiology
• Comparative exposure / risk assessment
• Expert opinion
• Molecular epidemiology
– microbial subtyping e.g. PCR, source tracking, population
genetics and epidemiological modelling add powerful tools
– rMLST (new generation) uses high throughput sequencing of
whole genomes to analyse many more genomic loci
www.mpi.govt.nz • 11
Modelling approach
www.mpi.govt.nz • 12
Massey University EpiLab 2005 -
• Manawatu sentinel
site
• Identify genotypes
common to
particular sources
www.mpi.govt.nz • 13
Campylobacter source attribution
www.mpi.govt.nz • 14
Attribution 2011/12
Attribution 2005/6
???
Campylobacter source attribution
2005 / 2006
2011 / 2012
www.mpi.govt.nz • 15
0
1
2
3
4
5
6
7
00 00 00 00 01 01 01 01 02 02 02 02 03 03 03 03 04 04 04 04 05 05 05 05 06 06 06 06 07 07 07 07 08 08 08 08 09 09 09 09
1 3 5 7 9 11 1 3 5 7 9 11 1 3 5 7 9 11 1 3 5 7 9 11 1 3 5 7 9 11 1 3 5 7 9 11 1 3 5 7 9 11 1 3 5 7 9 11 1 3 5 7 9 11 1 3 5 7 9 11
Urban
Rural no cattle
Rural high cattle
Poultry intervention
2000 2001 2002 2003 2004 2005 2006 2007 2008 2009
Dynamic changes in source attribution
www.mpi.govt.nz • 16
Operational research
www.mpi.govt.nz • 17
Operational research on-farm
• On-farm risk factors for Campylobacter infection of
broilers under New Zealand conditions
• Potential dissemination of Campylobacter by farmers’
overalls in broiler farms
• Effect of caprylic acid on Campylobacter concentration
in broiler caeca
www.mpi.govt.nz • 18
On-farm
Risk factors Voluntary Biosecurity Manual
Environment
Pests
People
Equipment
Cross contamination
during live bird
transport to
processing
Contaminated birds
• Environmental hygiene
• Entry procedures
• Minimise partial depopulations
• Catching procedures
• Crate washing, drying and
sanitation
• Education and commitment of
growers
www.mpi.govt.nz • 19
Live
birds
On-farm biosecurity; Campylobacter cf.
Salmonella
Production
(on farm)
Primary Processing
Secondary Processing
Distribution and Sale
Preparation and
Consumption
Feed
Drinking
water
Environment
Pests
People
Equipment
Minimise Campylobacter on Farm:
- farm biosecurity
Break Salmonella cycle on-farm:
- heat treat feed
- treat drinking water
- controls for grandparents, parents, hatcheries
- strict farm biosecurity
Manage Campylobacter at Primary Processing
-
www.mpi.govt.nz • 20
Code of practice for primary processing
www.mpi.govt.nz • 21
Operational research at primary processing
• Surveys: Broilers, end-of-lay, breeders, turkeys, ducks,
free-range poultry
• Quantification of Campylobacter from internal and
external carcass rinses
• Longitudinal mapping of Campylobacter on carcasses
• Campylobacter recovery from carcasses
• NMD: Investigation of “Not Detected” rinsates
• Chlorinated compounds formed during chlorine wash
of chicken meat
• Immersion chilling: Effect of washing and chlorination
www.mpi.govt.nz • 22
Operational research: Effect of temperature
• Effect of low temperature on Campylobacter on poultry
meat e.g. crust freezing
• Domestic food practices: Refrigerator survey and meat
handling survey
• Domestic food practices: Quantifying the reduction of
Campylobacter on skin-on chicken breasts frozen and
stored up to 10 weeks at -12oC
www.mpi.govt.nz • 23
Primary processing
Post-mortem
examination
Defeathering
Evisceration
Initial chilling
(immersion chillers)
New equipment / equipment set up
Equipment rinse
Post-defeathering rinse (total bird)
Equipment set up (bird size dependent if automated)
Equipment rinses
Multiple bird rinses (total bird)
Pre-chill tank (remove organic matter) Effective immersion chiller operation
•High flow rate (counterflow) •Chlorine control •pH correction •Contact time
Additional post-chill antimicrobial dips
Risk factors Industry actions / Control measures
Personal hygiene
Hand and knife wash stations
www.mpi.govt.nz • 24
Primary processing
• Free-range birds have higher initial levels of
Campylobacter than fully housed birds
• In-line washing and immersion washing decreases
loads by at least one log
• Chlorine immersion decreases loads by at least a
further log
• Higher levels of organic contamination lessens effect
of chlorine (value of pre-chill tank wash)
www.mpi.govt.nz • 25
Operational research: Secondary processing
and consumer
• Effect of secondary processing on
contamination
• Contamination of offal and mechanically
separated meat products
• Contamination on carcasses and portions at
retail
• Campylobacter in drips trapped in leak-proof
packaged retail poultry
• Burden of disease and cost-benefit
www.mpi.govt.nz • 26
Results
www.mpi.govt.nz • 28
Percentage > 3.78 log 10 cfu/carcass
Monthly percentage of samples > 3.78 log10 CFU
0%
5%
10%
15%
20%
25%
30%
35%
2007
4
2007
6
2007
8
2007
10
2007
12
2008
2
2008
4
2008
6
2008
8
2008
10
2008
12
2009
2
2009
4
2009
6
2009
8
2009
10
2009
12
2010
2
2010
4
2010
6
2010
8
2010
10
2010
12
2011
2
2011
4
2011
6
2011
8
2011
10
www.mpi.govt.nz • 29
The premises effect: % positive rinsates
0%
10%
20%
30%
40%
50%
60%
70%
80%
Feb-11 Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan-12
A
B
C
D
E
F
G
7 ST premises
Campylobacter positive rinsates of different poultry premises
www.mpi.govt.nz • 30
Variable performance at processing steps
0
1
2
3
4
5
6
7
Before evisceration After evisceration After immersion chilling
log
10 C
FU
/ rin
sate
Mean counts (log10 CFU/rinsate) of the outside of the carcasses
Premises A
Premises B
NZ MPI Campylobacter in poultry programme
www.mpi.govt.nz • 31
-
0,10
0,20
0,30
0,40
0,50
0,60
0,70
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200
400
600
800
1000
1200a
vr.
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Notifications
Variable Association between human cases and % positive
carcasses
www.mpi.govt.nz • 32
Variable Association between human cases and % > 3.78
log 10 cfu/carcass
-
0,05
0,10
0,15
0,20
0,25
0,30
0,35
0
200
400
600
800
1000
1200
avr.
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avr.
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janv.-
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14
Notifications
www.mpi.govt.nz • 33
Examples: Compliance Response Team
Issue
Regulatory action
Higher loading (free range), gut breakage, insufficient carcass
washing, sub-optimum management of chemical decontamination
steps
Follow up by VA
Large bird contamination (line speeds), sub-optimum management of
chemical decontamination steps
Follow up by VA
Poor separation between kill and EV rooms, plucker splatter, organic
so needed extra wash steps and use of approved chemical in multiple
decontamination steps
CRT visit
Direction to freeze product,
CRT visit
CRT visit
General hygiene issues, line speed too high, lack of staff, poor
evisceration equipment set up, lack of washing (post pluck, post EV)
/chemical decontamination steps
CRT visit
Direction to freeze product
Direction to add chemical
intervention
General hygiene issues, poor evisceration equipment set up, lack of
control of salting, lack of washing (post pluck, post EV) /chemical
decontamination steps
CRT visit
Direction to freeze product
Insufficient samples, incorrect testing, lack of washing (post pluck,
post EV), poor separation between kill and EV rooms, plucker splatter,
poor control of chemical decontamination steps
CRT visit
www.mpi.govt.nz • 34
Progress against public health goal
www.mpi.govt.nz • 35
Risk management
www.mpi.govt.nz • 36
• Increased stringency could focus on a further
improvement in national performance and/or an
improvement in poorest performing premises
• Target could incorporate tighter acceptance
number, tighter limit etc.
• Risk assessment needed to inform decision but
note that a target does not represent actual
performance of industry
Risk management option: Tightening performance target
www.mpi.govt.nz • 37
• Simple pathway model: Estimates changes in
NMD results with different interventions at the
premises level
• Simple regression model: Estimates human
health risk using NMD data at national level
(noting that it is not possible to directly model the
CPT)
• Alert tool: Simulates alerts and responses for
individual premises using retrospective data and
different inputs to the CPT)
Risk assessment tools
www.mpi.govt.nz • 38
Simple pathway model: Screen shot
Data entry
Changes to routine process
Level immediately after processing step
Unit Distribution
On farm (Caecal prevalence) 50% Percentage
Change
50%
Pre scalding 8.21 CFU log10 \ rinsate Triangular
Additional Change CFU log10 \ rinsate
Scalding and defeathering Effect -1.67 CFU log10 \ rinsate Triangular
Additional Change CFU log10 \ rinsate
6.54
Evisceration Effect -0.18 CFU log10 \ rinsate CDF-Based independent samples
Additional Change 0.00 CFU log10 \ rinsate
6.36
Spin chilling Effect -2.71 CFU log10 \ rinsate CDF-Based independent samples
Additional Change CFU log10 \ rinsate
3.65
www.mpi.govt.nz • 39
Regression model for human illness (1)
NMD % samples
> 3.78 log 10 cfu /
carcass
20%
15%
10%
5%
3%
1%
Campylobacteriosis
notification rate
(per 100,000)
208
187
166
146
135
129
Feb 2011 to
Jan 2012:
8%
April 2007 –
March 2008:
22%
Feb 2007 – Jan
2012: 8%
www.mpi.govt.nz • 40
Regression model for human illness (2)
NMD % positive
samples
70%
60%
30% 25%
20%
Campylobacteriosis
notification rate
(per 100,000)
April 2007 to
Mar 2008:
50%
Feb 2011 to
Jan 2012:
39%
35%
40%
45%
50% 55%
65%
75%
268
236
141 125
109
157
173
188
204 220
252
283
April 2007 –
March 2008:
50%
Feb 2011 – Jan
2012: 39%
www.mpi.govt.nz • 41
Alert modelling tool: screen shot
NMDxyz
0
0.5
1
1.5
2
2.5
3
3.5
2007 5
2007 8
2007 1
2
2008 3
2008 5
2008 8
2008 1
0
2009 1
2009 3
2009 5
2009 8
2009 1
0
2010 1
2010 3
2010 6
2010 8
2010 1
0
2011 1
2011 3
2011 5
Pos_alert
>3.78_alert
Combined
Acceptance number 20 6
MW_Positives MW_>3.78
www.mpi.govt.nz • 43
Revised performance standard: 2013 -
Premises Enumeration
Failure (EF)
Detection
Failure (DF)
Escalation of
Responses
Clearance
ST:
> 1,000,000
birds per
annum
When 7 or more
out of 45
samples are >
3.78 log10CFU/
carcass
When 30 or
more out of 45
samples are ≥
2.30 log10CFU/
carcass)
If the premises
has an EF, a DF
or both it is
counted as one
non-compliant
window.
Responses
escalate
according to the
number of
consecutive non-
compliant
moving windows.
To clear the
non-compliance
a moving
window without
an EF and
without a DF is
required. The
database then
resets to zero to
show that the
premises is
compliant.
VLT:
All others
When 2 or more
out of 9 samples
are > 3.78
log10CFU/
carcass.
When 6 or
more out of 9
samples are ≥
2.30 log10CFU/
carcass.
www.mpi.govt.nz • 44
Campylobacteriosis cases per quarter
www.mpi.govt.nz • 45
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Notifications
Variable Association between human cases and % positive
carcasses
www.mpi.govt.nz • 46
Variable Association between human cases and % > 3.78
log 10 cfu/carcass
-
0,05
0,10
0,15
0,20
0,25
0,30
0,35
0
200
400
600
800
1000
1200
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Notifications
www.mpi.govt.nz • 47
Changing epidemiology presents challenges
www.mpi.govt.nz • 48
Changing epidemiology presents challenges
www.mpi.govt.nz • 49
Discussion
• Achieving gains based on biosecurity is a challenge
• New Zealand control programme focuses strongly on
controlling contamination at primary processing by use of
a mandated target rather than mandated interventions
• Working closely with industry to improve situation
• Must be a consequence for poor performance
• Washing of carcasses has demonstrable effect and
chemical decontamination used where necessary
• Further stringency in performance target must be driven
by transparent risk management decisions
www.mpi.govt.nz • 50
Campylobacteriosis: A prime example for a risk-
based approach!
Thank you
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