campylobacter: is there light at the end of the...

Campylobacter: is there light at the end

of the tunnel?

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

WHO-Collaborating Center for Campylobacter/OIE Reference Laboratory for Campylobaceriosis

[email protected]

Outline

Campylobacter - some facts

Source attribution

Control options and expected effects

Campylobacter in Europe

Potential approach to reduce the burden

Take home messages

The importance of Campylobacter for humans

Campylobacter jejuni/coli is the most common cause of

bacterial intestinal disease in Europe Estimated at 10 million cases per year in EU (costs: 2.4 billion)

Serious outcome 35-45 per 100,000 ill (EU); 3.5-4.0 hospitalized; 0.15-0.30 fatal

Sequelae Guillain Barré Syndrome, Irritable Bowel Syndrome, Reactive Arthritis

=> contributing heavily to the burden of illness

Largest part of the world: no data

Campylobacter in poultry

Campylobacter in poultry

newly hatched chicks are Campylobacter free

colonisation < 10 days rare - maternal immunity?

colonisation is age dependent (organic production)

up to 109 cfu per gram cecal contents (amplification vessel)

asymptomatic and lifelong for broilers, slight decline in older birds

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

strong seasonality

only decline of counts after slaughterhouse

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

0

100

200

300

400

500

600

700

800

900

1000

April May June July

Re

gis

tere

d c

as

es

1998 1999

Dioxin crisis

Campylobacteriosis incidence in Belgium

0

20

40

60

80

100

120

140

jun

jul

au

g

sep

ok

t

no

v

de

c

jan

feb

mrt

ap

r

mei

jun

jul

au

g

sep

ok

t

no

v

de

c

jan

feb

mrt

ap

r

mei

jun

jul

au

g

sep

ok

t

2002 2003 2004

Weekly

nu

mb

er

of

cases c

am

pylo

bac

teri

osis Observed Expected Tolerance

Avian

influenza

outbreak

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…..

Source attribution based on different approaches



Intervention studies: 40% attributed to poultry meat

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

othersources

20-30%

50 - 80%

Interventions in the poultry meat production chain

What are we aiming for?

Preferably absence in flocks, second best:

reduced cecal concentration at slaughter

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”

What measures in primary production?

Prevention of introduction of Campylobacter into the

broiler houses

reduced fraction of positive flocks

Increased resistance of broilers to become colonized

reduced fraction positive flocks and (potentially) decreased

Campylobacter counts/gram cecal contents

Decreased concentration of Campylobacter in intestines

just before slaughter

Decreased concentration in gut contents associated with lower

carcass counts.

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

Positive association with colonization

Thinning

Other animals

Other poultry houses

Age

Water supply

Negative association with colonization

Implementation of biosecurity measures

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

Dr. Ruff Lowman

Ruff Biosecure Inc.




Vaccination

Phage therapy

Genetic resistance

Bacteriocines

1,00E+00

1,00E+01

1,00E+02

1,00E+03

1,00E+04

1,00E+05

1,00E+06

1,00E+07

1,00E+08

1,00E+09

1,00E+10

0 5 10 15 20 25 30 35 40 45

day

cfu

/g p

fu/g

Average CFU

Average PFU

Campylobacter inoculation

Campylobacter colonization: bacteria only

1,00E+00

1,00E+01

1,00E+02

1,00E+03

1,00E+04

1,00E+05

1,00E+06

1,00E+07

1,00E+08

1,00E+09

1,00E+10

0 5 10 15 20 25 30 35 40 45

day

cfu

/g p

fu/g

Average CFU

Average PFU

Phage dosage

Campylobacter inoculation

Campylobacter colonization: therapeutic treatment




Vaccination

Phage therapy

Genetic resistance

Bacteriocines

Quantification of measures

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

39

Economic aspects

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

Costs and benefits analysis

Campylobacter in Europe: EU data

EFSA-ECDC Zoonoses report 2011

Campylobacter trend EU

EU – baseline study in 2008

Includes flocks and carcasses of broilers

Objectives:

'baseline' prevalence in all member states in ceca and

carcasses (neck skins)

Enumeration of Campylobacter from neck skins

Inclusion: 10,132 flocks in 561 slaughterhouses

in 26 EU member states (+NO&CH)

Luxembourg

Luxembourg

FranceUK

Dutch approach: process hygiene criterion

To control contamination of end-products in industrial

slaughter plants for broiler chickens (carcasses after chilling)

Treshold based on risk assessment models

1000 cfu/gram neck/breast skin

Not complying is a sign that hygiene of the slaughter plant

should be improved (=> develop and implement a plan for

improvement)

Not complying batches will not withdrawn

Discussion about introduction at EU-level

CONTROLLING CAMPYLOBACTER ON BROILER MEAT:THE DUTCH APPROACH | March 13, 2013

51

FSA- UK

The FSA expects industry to focus its actions to:

continue to improve the effectiveness of biosecurity

measures on farms to prevent flock colonisation with

campylobacter

ensure that steps involved in slaughter and processing are

effective in preventing contamination of carcasses

continue to work on packaging and other initiatives that

reduce cross contamination in the consumer and food

service kitchen

develop and implement new interventions that reduce

contamination when applied at production scale

The role of the consumer!!!

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

Take home messages Up to 80% of human campylobacteriosis 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!)

Efforts on primary production AND postharvest

Elimination of the highly contaminated carcasses reduces the human burden

considerably

Potential approach: process hygiene criterium

To survive as risk manager: do not make any promise for reduction for the

future!

Thanks to...

Albert de Boer

Ria van der Hulst

Frans Putirulan

Fimme Jan van der Wal

Peter Willemsen

Conny van Solt

Miriam Koene

Rene Achterberg

Dik Mevius

Kees Veldman

Marga Japing

Marcel van Bergen

WHO Global Food borne Infections Network

Eelke Pothoven

Wilma Jacobs

Nico Bolder

Birgitta Duim

Linda van der Graaf

Paulo de Boer

Esther Gaasbeek

Ellard Kruijt

Alan Rigter

Jeroen Dijkstra

Arie Havelaar

Joost Smid

Twan van Gerwe

Wilfrid van Pelt

Hubert Endtz

Diane Newell

Lapo Mughini Gras

Ingrid Friesema

Nigel French

Rob Tauxe

Charles Hofacre

Irving Nachamkin

Ruwani Kalupahana

Rob Lake

Patrick McDermott

Shaohua Zhao

April 2002…..

92 children and 3 teachers visited a farm

57 children and 3 teachers drunk fresh milk from

the milktank

Six days after the farm visit…..

28 children ill (watery diarrhoea, some with blood

and fever >40°C)

common exposure: farm visit

questionnaire: milk

Relationship milk/case

Case: Yes No total

Milk: Yes 28 29 57

No 2 33 35

Total 30 62 92

Dose-respons relation

Case: yes no total %-case rel.risk

Milk: No 2 33 35 6 1.0

1 swig 2 10 12 17 2.9

1/2 cup 7 11 18 39 6.8

1 cup 13 8 21 62 10.8

2 cups 6 0 6 100 17.5

total 30 63 92

Culture of Campylobacter

17 days after the visit 18 samples:

11 positive direct (all patients)

1 positive after enrichment (control)

6 negative (all controls)

no sample from the milktank

Discussion

Farmer was not convinced

Milk can be contaminated with feces

Many outbreaks described

Consumption of raw milk?

The importance of Campylobacter

Campylobacter jejuni/coli is the most common cause of

bacterial intestinal disease in Europe

Estimated at 10 million cases per year in EU27; costs 2.4 billion €

Incidence and consequences of infection are high

35-45 per 100,000 ill; 3.5-4.0 hospitalized; 0.15-0.30 fatal.

Underreporting is common

true rates 10-100X

EFSA Journal 2010; 8(1):1437

campylobacter: is there light at the end of the...

Documents