Campylobacter : food safety aspects and interventions

Campylobacter: food safety aspects and

interventions

Prof. Jaap A. Wagenaar, DVM, PhD

Dept. Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands

Central Veterinary Institute, Lelystad, The Netherlands

[email protected]

Outline

Campylobacter: introduction

Control options in primary production

Control options in processing stage

Success stories

Future approach to reduce the human Campylobacter burden

Instructions for the consumer

WHO/FAO/OIE Expert Consultation (July 2012)

Campylobacter

Sensitive for heat, dryness, disinfection,... C. jejuni (92% of gastro-intestinal infections)

C. coli (5% of gastro-intestinal infections)

Many (all?) animal species are asymptomatic carrier of Campylobacter

Campylobacter and disease in humans Most common bacterial cause of foodborne disease in

Europe and the US. Europe: estimated at 10 million cases per year in EU27; costs 2.4

billion € Europe: 35-45 per 100,000 ill; 3.5-4.0 hospitalized; 0.15-0.30 fatal. Middle East?

Common cause of diarrhea in infants and young children in developing countries

Global burden ??

Campylobacter-induced clinical illness Acute phase: diarrheal disease (incubation time 2-5 days;

self limiting)

Sequelae: Guillain Barré Syndrome (damage of peripheral nervous system)

0.1% of campylobacter cases

Reactive arthritis: 1-5% of campylobacter cases

Post-Campylobacter Irritable Bowel Syndrome: 30% of the campylobacter cases

Campylobacteriosis

Outbreaks are rare compared to Salmonella

Even low doses has an high probability of

infection

Sepsis and extra-intestinal infections are rare

Campylobacter trend EU

Campylobacteriosis: sources of infection

Poultry meat Contaminated drinking water Travelling Raw milk Direct animal contact

Cross-contamination

Source attribution

Can we estimate the attribution from the different sources to human campylobacteriosis?

and estimate the expected impact of control

measures?

Human illness source attribution methods


Case control studies and outbreaks: 24-29% attributed to poultry meat


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Campylobacteriosis incidence in BelgiumCampylobacteriosis incidence in Belgium

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Avianinfluenzaoutbreak

data from Wilfrid van Pelt, RIVM

Source attribution based on different approaches


Intervention studies: 40% attributed to poultry meat


Multi Locus Sequencing Typing (MLST)

DNA-sequence based method

Strains from different sources (chicken, cattle, dog, human, pigs, environment)

All information in 1 database (Oxford, UK)

Mathematical modelling…..

Outcome: what strains in humans are most likely from…..




Microbial subtyping (MLST): 50-80% attributed to poultry





● The goal is to estimate the relative contribution (%) of different (amplifying) reservoirs for Campylobacter to human infections

● It provides no information on the transmission pathways by which Campylobacter arrives to humans from the different reservoirs

Case-control

information

Source attribution information

Results – Source attribution

Interventions

Intervention in the poultry meat production chain can prevent potentially 30-40% of the human infections at meat consumption level

Intervention in the primary production can prevent potentially up to 80% of the human infections

other sources

20-30%

50 - 80%

Campylobacter in poultry

Colonisation of Campylobacter in broilers

newly hatched chicks are Campylobacter free

colonisation < 14 days rare - maternal immunity?

colonisation is age dependent (organic production)

up to 109cfu per gram cecal contents

asymptomatic and lifelong for broilers, slight decline in older birds

almost 100% of birds in a flock become positive within a few days

Campylobacter and poultry meat

Contamination of carcasses during processing

organisms don’t grow but survive well to retail

cross contamination of other foods is common

a single drop of fluid from a positive bird can contain ~106 cfu

Interventions in the poultry meat production chain

What are we aiming for?

Preferably absence If colonization cannot be prevented in primary

production, the processing plant is in charge Eliminate the heavily contaminated carcasses

Quantitative risk assessment models indicate that “the incidence of campylobacteriosis associated with consumption of chicken meals could be reduced 30 times by introducing a 2 log reduction of the number of Campylobacter on the chicken carcasses”

Risk factors for farms to be Campylobacter positive (input for intervention)

Increased Thinning Other animals Other poultry houses Age Water supply

Decreased Implementation of biosecurity measures

On-farm interventions: 3 approaches

Prevent Campylobacter entering broiler houses during primary production

Increase resistance of broiler chickens to colonisation

Reduce the concentration of Campylobacter in chicken intestines before slaughtering

Prevention of introduction of Campylobacter: biosecurity

poultry farm

Prevention of introduction of Campylobacter

farm

Prevention of introduction of Campylobacter

farm

25 gram cecal content x 109 x 50,000 broilers =

1015 campylobacters/day

1 broiler can be become colonised with 50 campylobacters

On-farm interventions

Biosecurity (including fly screens) Thinning, consistently & rigorously applied, only indoor!

Feed and water additives (acids, competitive exclusion, probiotics)

Vaccination

Phage therapy

Genetic resistance

Bacteriocines




Vaccination

Phage therapy

Genetic resistance

Bacteriocines

Dr. Ruff Lowman

Ruff Biosecure Inc.




Vaccination

Phage therapy

Genetic resistance

Bacteriocines




Vaccination

Phage therapy

Genetic resistance

Bacteriocines




Vaccination

Phage therapy

Genetic resistance

Bacteriocines




Vaccination

Phage therapy

Genetic resistance

Bacteriocines




Vaccination

Phage therapy

Genetic resistance

Bacteriocines

Quantification of measures

Quantitative effect of interventions

Study by European Food Safety Authority

Description of risk factors and interventions (based on literature review and EU baseline study)

Estimation of effect of interventions on risk reduction of human campylobacteriosis and ranking (based on quantitative mathematical model)

Description of advantages and disadvantages of potential interventions and time scale for availability

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Selected interventions to be analysed by mathematical model

Biosecurity

Fly screens

Discontinued thinning

Reduction of slaughter age

Reducing colonization by different approaches

Decontamination

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Effect of interventions based on QMRA (request from EFSA)

100% risk reduction can be achieved by irradiation/cooking

> 90% risk reduction can be achieved by freezing for 2-3 weeks or reduction

of the concentration in intestines at slaughter by > 3 log units;

50-90% risk reduction can be achieved by freezing for 2-3 days, hot water or chemical carcass decontamination with lactic acid, acidified sodium chlorite or trisodium phosphate

50-90% risk reduction by fly screens on farms (based on data from Denmark only)

Up to 50% risk reduction by modifications of primary production, restriction of slaughter age to a max 28 days (only indoor flocks) discontinued thinning

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Economic aspects

http://ec.europa.eu/food/food/biosafety/salmonella/other_act_en.htm

Costs and benefits analysis

Success stories

Landspítali-háskólasjúkrahús. Sýklafræðideild

Verified Human Campylobacter Cases

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Verified human Campylobacter cases

Iceland

Freezing campy pos carcasses

New Zealand data

Data Sources: ESR Ltd notification data; NZHIS hospitalisation data (filtered)Data Sources: ESR Ltd notification data; NZHIS hospitalisation data (filtered – thanks to Nigel French, Rob Lake and A. Sears)

Future control options for Campylobacter

EU: targets (counts per gram product)

Take home messages Campylobacter is the leading cause of bacterial enteric illness

and associated with considerable morbidity

Up to 80% is poultry derived with 20-40% through poultry meat

Options for intervention in primary production are still (economically) limited and restricted to indoor production (animal welfare conflicting with food safety!)

Aiming for Campylobacter negative flocks arriving at slaughterhouse; if not, go for the low counts per gram.

The public health benefits of controlling Campylobacter in primary broiler production are expected to be greater than control later in the chain (due to non-poultry meat transmission routes)

Instructions for the consumer!!!

Dr. Henk van der Zee, Food Inspectorate, the Netherlands

Source attribution

Can we estimate the attribution from the sources for human campylobacteriosis?






Data: Dr. Frank van Loock

0100200300400500600700800900

1000

April May June July

Reg

iste

red

cas

es

1998 1999

Dioxin crisisDioxin crisis

Campylobacteriosis incidence in BelgiumCampylobacteriosis incidence in Belgium





Documents

Campylobacter : food safety aspects and interventions