VFD standard skabelon

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Transfer and survival of Campylobacter in the
consumer phase Bjarke Christensen, Helle Sommer,
Niels Nielsen, Hanne Rosenquist and Birgit
Nørrung. Danish Veterinary and Food
Administration Division of Microbiological Safety

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Objectives
Provide guidelines to set up risk management
options

• Performing a quantitative risk assessment
  provides
• an overview of the spread of Campylobacter from
  slaughterhouse to consumer
• an overview of the data availability, data gaps
  etc.
• An idea about the relative importance of
  different steps at the production, retail and
  consumer level on the risk of getting ill after
  consumption of a chicken serving
• Mitigation strategies (relative risk estimates)
• An estimate

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Outcome of the Danish risk asssessment

• Consider the following strategies
• Reduce flock prevalence
• Reduce numbers on chicken carcasses
• Improve kitchen hygiene
• Young adults are at higher risk
• Logistic slaughter problably not important.

- Reduce numbers on chicken carcasses
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Preparation and consumption of meals
Microorganism
Transfer/survival
Numbers
Raw chicken
Meal
Hygiene
Freguencies
Individuals
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Transfer and survival in the kitchen environment
Heat treatment-
Raw chicken
Hands
Exposure
Cutting board, Utensils etc.
Ready-to-eat food (salad, bread etc.)
Storage
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• Fraction transferred (k)
• Numbers transferred depends on mechanical
  parameters
• e.g. liquids excreted
• size of contact areas.
• May vary significantly from one handling event to
  the next.
• For some processes the distribution may be broad
  and for others relatively narrow.
• Frequency (f)
• Depends on status of individuals
• Hygiene habits
• Frequency of preparing a meal

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Preparation processes
f1k1 f2k2 fxkx fn-1kn-1 fnkn
Numbers on chicken
Dose in meal
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Hygiene
Bad Not washing cutting board fncbkncb
Better Washing cutting board, but using same
cutting board fcb kcb
kcb
Log10 fraction transferred
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Preparation processes
f1k1 f2k2 fxkx fn-1kn-1 fnkn
Numbers on chicken
Dose in meal
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Reduce number of Campylobacters on chicken
carcasses
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Effect of reducing Campylobacter load on raw
chicken products
Relative change in positive meals
Change on chickens (Log10 cfu/chicken)
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Effect of reducing Campylobacter load on raw
chicken products
Change on chickens (Log10 cfu/chicken)
Log10 fraction transferred
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Changing accetable minimum load in a meal
Log10 fraction transferred
Change on chickens (Log10 cfu/chicken)
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Guidelines to risk managers Reduction
strategies can be very efficient But The
effect will be less efficient in cases
with extremely bad kitchen hygiene (High
transfer rate) Significant effect for good, but
not perfect hygiene (Medium transfer rate) Less
efficient for highly susceptible people
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Conclusions Combine reduction strategy with
education Data gap Preparation habits related
to incidence. Quantitative measures on raw
products not enough True estimates not
considered Major disadvantage Do not produce
safe meals in a controlable manner
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(No Transcript)
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Prevalence of positive meals
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Quantitative transfer DATA

• Chen et al. (2001)
• Zhao et al. (1998)

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Preparation hygiene in private kitchens
(Yang et al. 1998)
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Consumption patternsUse of diatary surveys

• Food preferences
• Size of meals
• Where is the food ingested
• Restaurants
• At home
• Who prepare the food
• Sub populations
• Age
• Gender
• Ethnic
• Education

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Link between consumer and person preparing the
food in private homes
Preparation (preparer)
Consumer
Kitchen hygiene Who prepare the food
Chicken meals ingested Meals ingested at home
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DATA (I)

• The consumer
• Frequency of ingesting chicken meals
• Frequency of ingesting meals at home
• Household/family relationships
• Who prepare the food
• Who prepare for who
• Family/household types
• Family size

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DATA (II)
Danish Dietary Survey (Andersen et el.
1996) National demographic data (Statistics
Denmark)
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Results
Frequency of ingesting chicken meals at home
where the cutting board has not been washed
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• Pointer der skal frem
• Hovedformål er at give guidelines til risk
  managers
• Estimater er ikke vigtige
• Det samlede antal sygdomstilfælde er
  kendt/fixeret.
• D.v.s. hvis f høj så er k lav og omvendt
• F høj k lav ? mindre effekt ved at reducere antal
  på carcass
• F lav k høj ? stor effekt ved at reducere antal
  på carcass