Microbiological Risk Assessment, taking thermophilic Campylobacter spp' as an example

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Microbiological Risk Assessment,taking
thermophilic Campylobacter spp. as an example

• Edda Bartelt, Juliane Bräunig and Ekkehard Weise
• Federal Institute for Risk Assessment (BfR)

IUFoST Food Ingredients - Production and
Perception in a New European Environment Challeng
es of entering the Expanded European Market
Place Berlin, 25 - 26 May 2004
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Content

• I. Food Hygiene concepts
• II. Structure for Risk analysis in Germany
• III. Quantitative Risk Assessment of
  Campylobacter spp. in chicken

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Food Hygiene - former concept

• fixed requirements for equipments and
  facilities of food companies
• randomly official control by food authorities
  (control of hygienic conditions and of end
  products)
• systematically control on border lines of all
  imported food batches
• self control system in companies end
  products, sampling plans

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Food Hygiene - new concept

• "from farm to fork"
• more control of processes, less check of end
  products
• enforcement of responsibility of companies
• mandatory self control system in
• control of the control by food authorities

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HACCP- CONCEPT
1. Hazard analysis2. Determination of Critical
Control Points 3. Fixation of limits4.
Monitoring 5. Corrective actions 6.
Verification 7. Documentation
BfR/We/04.2003
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Risk Analysis

• Risk assessment ? Assessment
• Risk management ? Decision
• Risk communication ? Exchange of
  informations

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Risk Analysis in Foods in the EU

• Regulation (EG) Nr. 178/2002 of the European
  Parlament and the Council from 28. Januar 2002
  for general requirements for food regulations
  and for Establishment of the European Food Safety
  Agency

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Consumer protection in the EU
Risk Management
Risk Assessment
European Commission FVO
EFSA
Europ. Parl.
Europ. Council
EU
Ger. BMVEL BVL
Ger. BfR
Member States
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Federal Institute of Risk Assessment- Task -

• Detection and Assessment of Risks
• - on own inititative - on requirements of
  the risk managements (Ministries, Federal
  Office of Consumer Protection and Food Safety
  - BVL)
• Elaboration of management options
• National counterpart of EFSA
• Cooperation with other Risk Assessment
  institutions
• Research activities
• Risk Communication (PR, consulting of other
  institutions and interested groups)

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Why Risk Assessment?

• 1. FAO/WHO-Report (1995)
• It should be the role of official bodies to use
  risk analysis to determine realistic and
  achíevable risks levels for food-borne hazards
  and to base food safety policies on the practical
  application of the results of these analyses
• 2. SPS-Agreement (WTO, 1994)
• International Trade Agreement, ...For
  establishment of rational harmonised
  regulations and standards for food in
  international trade, a rigorous scientific
  process is required....
• 3. Elements of Food Safety Risk Analysis (RM, RA,
  RC)
• as a basis for elaboration of FSOs
• 4. RA-Principles of Codex Alimentarius
• 5. National task
• Research network Epidemiology of foodborne
  infections

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Definitionen
Codex Alimentarius
Risk Assessment - A scientifically based process
consisting of the following steps (i) hazard
identification, (ii) hazard characterization,
(iii) exposure assessment, and (iv) risk
characterization.
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Definitions hazards vs. risk
Hazard
a biological, chemical or physical agent in, or
condition of, food with the potential to cause an
adverse health effect
Risk
a function of the probability of an adverse
health effect and the severity of that effect,
consequential to a hazard(s) in food
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Definition Risk assessment
Codex Alimentarius Quantitative Risk Assessment
A Risk Assessment that provides numerical
expressions of risk and indication of the
attendant uncertainties (stated in the 1995
Expert Consultation definition on Risk
Analysis). Qualitative Risk AssessmentA Risk
Assessment based on data which, while forming an
inadequate basis for numerical risk estimations,
nonetheless, when conditioned by prior expert
knowledge and identification of attendant
uncertainties permits risk ranking or separation
into descriptive categories of risk.
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Infektionsepidemiological Network Foodborne
Infections in Germany Campylobacter
LGL Bayern
Bremen / Hannover / Münster
Prevalence of C. spp. in Poultry Products
Strains from Human Infections in
Bavaria (Sub-Typing)
Rural Urban C.spp. Infections in Lower Saxony
Hamburg
RKI (Coordination)
Identification of Outbreaks (Fast Sub-typing
Method)
Incidence Data (IfSG)
BfR Quantitative Risk Assessment of Human
Campylobacteriosis Associated with Campylobacter
jejuni in Chickens Interdisciplinary Team
Veterinarians, Biologists, Physicians,
Mathematitians
Survey Handling of chicken in German Homes
Impact of Cross-Contamination and Undercooking on
the Risk
Prevalence Concentration of C. spp. on Chicken
Drumsticks
Quantitative Data C. spp. in chicken
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QRA Campy Models
Canada Fazil, A.M., R. Lowman, N. Stern, A.M.
Lammerding A Quantitative Risk Assessment Model
for C. jejuni in Fresh Poultry Draft Document,
Dezember 1999 Denmark Christensen, B., H. Sommer,
H. Rosenquist, N. Nielsen Risk Assessment on
Campylobacter jejuni in Chicken Products Danish
Veterinary and Food Administration, Januar
2001 FAO/WHO Hartnett, E., G. Paoli, A. Fazil, A.
Lammerding, S. Anderson, H. Rosenquist, B.
Christensen, M. Nauta Hazard identification,
hazard characterization and exposure assessment
of Campylobacter spp. in broiler chickens 2001
Preliminary Report Joint FAO/WHO Activities on
Risk Assessment of
Microbiological Hazards in Foods A
Draft Risk Assessment of Campylobacter spp. in
Broiler Chickens Autoren wie
oben, Erstautor Anderson, S. 2002- Risk
assessment of Campylobacter spp. in broiler
chickens and Vibrio spp. in seafood. Report of a
Joint FAO/ WHO Expert Consultation , Bangkok 5-9
August 2002 2003 Interpretative Summary - A
draft Risk Assessment of Campylobacter spp. in
Broiler chickens Joint FAO/WHO Activities on
Risk Assessment of Microbiological Hazards in
Foods
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Framework

• 4 elements of Risk assessment
• Hazard identification Identification of the
  hazard Campylobacter in chicken as a risk factor
  for Campylobacteriosis
• Hazard charakterisation Assessment of the
  illness, Assessment of the relation between the
  foodborne exposition u and the probability of
  human health effects
• Exposure assessment Probability and degree of
  exposition to C. Due to consumption of chicken
• Risk characterisation Estimation of the Risk
  of illness in an given population and exposition
• Model Farm-to-Fork-chain

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Material and Methods

• 1) Surveillance-Systeme(e.g., Surveillance
  programs) and/or international studies
• 2) distribution function, no point estimation
• 3) Program for probabilistic estimation using
  Monte-Carlo-Simulation (_at_risk)

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Hazard Identification
1. Campylobacteriosis in Germany 2. Risk factors
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Incidence

• The second most important foodborne infection in
  Germany (after Salmonellosis )
• 2002 56.365 per reference definition,
  68,4 cases per 100.000 inhabitants
• 2001 54.410 66,2 Fälle per 100.000 inhab.
• Reference definition confirmed by clinical and
  microbiological detection
• plus clinical-epidemiological illness

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Involved Species

• 2002 in 46.876 Campylobacteriose cases
• 39.999 (84) C. jejuni
• 6338 (13,5) C.coli
• 1023 (2,2) C.lari
• 116 (0,2) C. fetus supsp. fetus
• 2001 in 46.635 Campylobacteriose cases
• 39.395(84,5) C. jejuni
• 6123 (13,1) C.coli
• 892 (1,9) C.lari
• 225 (0,5) C. fetus supsp. fetus

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Sources of sporadic infections C. jejuni
Chicken meat
poultry
poultry
men
pets
Raw milk, meat
Wild birds
cattle
water
Aus Nachamkin 2000 Friedman et al.
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Hazard identification

• 2. Risk factors
• chicken
• DK There is no C.-case, directly or
  indirectly linked with chicken (Germany 2
  outbreaks (Thurm u. Dinger 1997))
• high Prevalence rate in retail samples
• Case-control-studies worldwide Handling of
  raw meat and consumption of chicken products

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Hazard Identification

• other Risk factors
• Consumption of other types of meat
• insufficiently cooked or barbecued meat
• Seafood raw
• Consumption of untreated Surface water
• Consumption of raw milk
• Consumption of (cooked) meat in restaurants and
  unsufficient kitchen hygiene (cross
  contamination)
• travelling
• contact with pets
• recreational activities in nature

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Data sources in D- Prevalence

• 1. Surveillance German Zoonosen-Trendbericht
  2002)
• positive Broiler flocks
• 2002 2,76 (n181)2001 45,6
• positive Broiler
• 2002 27,36 (n859)
• 2001 5,93
• 2. Publications, e.g. 88,9 positive flocks
  (n9) ?
• ) German Zoonosis-Trend Report

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Data sources in D - Prevalence
1. Zoonosen-Trendbericht 2002chicken meat
2002 25 2. Publications high prevalence 80,
but saisonal variations, no comparable data,
depending on products, method etc. 3.
Campylobacter-Monitoring?? Coordinated programs
of food authorities 4. Studies, retails samples,
fresh chicken drum sticks, sampling plan
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Hazard characterisation
1. Illness, severity 2. Dose-response-relation
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Campylobacteriosis - Symptoms
Therapy symptomical, (antibiotical)
Aus Nachamkin 2000 Skirrow and Blaser
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Campylobacteriose - sequelae

• Reaktive Arthritis 1-7, after 1-2 weeks

Reiters-Syndrom Arthritis plus Urethritis,
Conjunktivitis/Iritis, Reiters-Dermatosis

• Guillain-Barré-Syndrom 0,4-5/100 000

• Haemolytic Anaemia, HUS, Carditis, Encephalopathy

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Hazard characterisation

• 2. Dose-response-Relation
• Robinson (1981) 500 Bacteria (?) in milk
  illness in 1 voluntary
• Black et al. (1988) 111 voluntaries, USA
  (Baltimore), ingestion of 8x10E2 - 2x10E7 KBE,
  Infektion f(dosis), but no clear dose relation
  to disease
• Rosenfield et al. (1985) outbreak, restaurant,
  C. in chicken meal 53-750 KBE/g detected
• MID may be relatively low

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Hazard characterisation

• 2. Dose-Response-Relation
• DK for establishment of dose-response-Model
• Data of Black et al.(1988) for estimation of
  probality of Infection and of disease

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Exposure assessment
2 mathematic models Modul 1 Slaughter and
Processing Modul 2 handling and
consumption AIM Estimation of probability and
high of of exposure to Campylobacter due to
consumption of chicken meal Prevalence and
concentration von C. in the farm-to-fork-chain No
model to growth!
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QRA Campy
Steps of Exposure assessment in
thefarm-to-fork-continuum
Slaughterhouse-Model Consumer-Model Prevalence
Pf Pp Pr Exposition probability far
m processing retail household
Risk Cf Cp Cr Infektion probabil
ity Concentration
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Data

• Denmark only use of Campy-Data
• Canada results of other bacteria
• WHO only experimentel Data (qualitativ and
  quantitativ) of Campy

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PrevalenceDK (2/98-1/99) 1 Slaughterhouse flock
prevalence N1/flock (n10) flock size sequenz
of slaughter AssumptionIn-flock-Prevalence0 or
100
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Retail DK 26 chilled (D 32, ZMP-Marktbilanz,
2002) C constant
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Contamination - directly (Schmierinfektion) -
insufficient cooked - cross contamination
during preparation of meals
Transfer by cutting board to the meal (Salad and
chicken meal)
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Data sources for consumption in Germany
How many of the population eat chicken? Who
eats chicken? How often (frequence)? How much is
eaten per meal? Etc. Data sources -
consumption studies -
ZMP (Käuferreichweite für Hähnchen, Kauf von
Hähnchen) - Questionaires (Emnid,
2001 CMA, 2000) -
Verzehrs- und Convenience- Monitor (Produkt und
Markt) - Monika Mengenliste - Nationale
Verzehrsstudie (Erhebungszeitraum 1985 -1989, N
20 000 Personen) - Bayrische Verzehrsstudie
(Erhebungszeitraum 1995, N 543 Personen) -
Ernährungssurvey des RKI (Erhebungszeitraum 1998,
N 4030 Personen) - Sächsische Verzehrstudie
(Erhebungszeitraum 1999, N1309 Personen)
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Risk characterisation
1. Risk estimation (risk estimate) d.h. the
estimated exposition will be integrated into
the Dose-Response-Model 2. Influence of
mitigation strategies
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Risk estimation
DK1 case / 14.300 chicken meal Basis 201
Mio. meals cases 4386 in 2000, estimated
30.000-400.000 age relation
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Risk estimation
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Influence of mitigation measures
1. Reduction of flock prevalence 2. Reduction of
Campylobacter on carcasses 3. Reduction of
crosscontamination between the flocks during
slaughter 4. Reduction of crosscontamination
during preparation DK Simulation of influence
of measures on (i) number of positive animals
in retail (ii) Campylobacter per positive
animal (iii) Incidence of Campylobacteriosis
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1. Reduction of flock prevalence
Relation between flock prevalence and A part
of pos. Chicken at end of slaughter
B Campylobacter on pos. chicken
C Incidence of Campylobacteriosis
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2. Reduction of Campylobacter on carcasses
Relation between chnage of Campylobacter (log
KbE/Tier) and
A part pos. Chicken at end of slaughter
B Campylobacter per positive animal
C Incidence of Campylobacteriosis
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3. Reduction of crosscontamination between flocks
during slaughter
Simulation of distribution of number of C. on
positive chicken of positive flocks (black) and
the number of C. On crosscontaminated chicken of
negative flocks (grey).
1. The Campylobacter on this cross contaminated
chicken from negative flocks was lower than in
chicken from C.-positive flocks, despite the
number of positive animals raised with
increaseing level of crosscontamination.
2. The probability, that C. Of crosscontaminated
chicken up to the ready to eat chicken meal is
due to crosscontamination by the consumer is also
low, and so the probability of Exposition and
disease
Logistic slaughter? low effect!
Bhalf Verdünnungseffekt zur Halbierung der
Campylobacter im Schlachtprozess, d.h. die
Anzahl der Karkassen, die geschlachtet werden
müssen, um die Campylobacter auf einem Tier um
50 zu reduzieren B half-Annahmen 1000 (A),
3000 (B)
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4. Reduction of crosscontamination during kitchen
preparation
Linear relation between unwashed cutting and
diseases !
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Conclusion

• Simulation DK(1) Incidence of
  Campylobacteriosis can reduced 30-x if,
• Campylobacter-Reduction by 2 log,
• Flock prevalence - Reduction by 30 x (e.g. from
  60 to 2)
• improvement of kitchen hygiene 30x, (e.g. part
  Dont wash cutting board von 21 auf 0,7)
• (2) effective Risk-Management-Options z.B.
• Log-Reduction, e.g. by freezing
• consumer education, mainly Risk people 18-29
  Jahre
• flock prevalence - Reduction, e.g. by hygiene
  barriers or Biosecurity zones Vaccination?
  CE?

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Conclusion

• (3) limits of modelling
• only part of population,
• chilled products from one country,
• only preparation at home,
• limited Input-Data, no quantitative data in
  slaughter and household
• not all assumption validated,
• only one study of Dose-response-relation
• simplification of modules
• ?