Microbiological Risk Assessment: Meat and Poultry Products

I Microbiological Risk
V Assessment: Meat and Poultry

Products

R K.N. Bhilegaonkar
I
Division Of Veterinary Public Health
Indian Veterinary Research Institute

Izatnagar

™ Introduction: Microbial food safety

™ Microbial Risk assessment steps with examples

–Hazard identification
–Hazard characterization
–Exposure assessment
–Risk characterization

™ Appropriate level of protection, Food safety
Objective

™ Avian influenza

Food Safety

I ¾ Increased global Important issue
trade

V ¾ Discerning and
knowledgeable
consumer

R
¾ BSE & nv CJD: UK

I ¾ Melamine in milk/milk products: China
¾ Pesticide residues in cold-drinks: India

¾ Avian Influenza: India and Asian countries

Microbial Food Safety

I ™ Foodborne illness : Global magnitude difficult to
V assess
R
I ƒ Deaths due to diarrhoeal diseases in 2005: 1.8 million
ƒ Developed countries: 30% population

(INFOSAN WHO 2008)

ƒ USA: 76 million cases of foodborne diseases

ƒ 325,000 hospitalizations
ƒ 5,000 deaths

ƒ India: Magnitude is unknown
ƒ Diarrhoeal diseases (Food and waterborne) :

18.6 million children under age of 5
ƒ 3,86,000 deaths in children (1 in every 5 global

deaths in children)

Transmission of Foodborne Diseases

I Animal feed/environment/protozoans

Food animals Manure

V Animal derived food products Plant derived products

R Food Processing Plants

I RTE Foods

Humans



Microbial Risk Assessment

I • A powerful tool for management of food safety
• Properly designed MRA: Objective and systematic

V evaluation of information
• Helps risk manager to take informed decision on food

R safety issue
• 1999: CCFH adopted principles and guidelines for
the conduct of MRA

I • Several Pathogen: commodity MRA : FAO & WHO,
developed nations
– Salmonella in eggs
– Listeria monocytogenes in cheese

MRA: India

I • No systematic MRA studies : Meat and
V poultry products

• Authentic and exhaustive base line data not

R available
• Vast country: Diverse culture/ethnicity

I • Tremendous variations in eating habits and
preferences
• Variations in risk patterns

HHaazzaarrddIIddeennttiiffiiccaattiioonn I
V
Hazard MEAT Food Intaket/ R
Characterization & Exposure I
assessment
POULTRY
PRODUCTS

Risk Characterization

HHaazzaarrdd

I IIddeennttiiffiiccaattiioonn
™ What are agents present in food?
V • Salmonella spp.
R • Listeria monocytogenes
I • Aeromonas spp.
• STEC
• Campylobacter spp.
• Staph. aureus
• Rotavirus

Food-agent relationship

Food-agent relationship!
™ Campylobacter Jejuni- Poultry
™ Listeria monocytogenes: Cheese/milk products
™ Clostridium perfringens: Meats
™ Aeromonas: Fish

™ No systematic surveillance studies in India
™ Several scattered reports: but gives fair idea

™ Prevalence in meat and poultry: 5 - 7%
™ RTE meats and poultry products: 0 - 3%

Western World: Important pathogen
Indian context: Prevalence of non-typhoidal
Salmonella less

™ 2541 serotypes
™ > 128 serotypes present in India

™ New added every year

Salmonella from food of animal origin

Agarwal (2009)

Type of food sample No. of No. positive (% ) positive
samples
Pork sausage examined 15 6.22
Cocktail sausage 241 9 4.32
Oxford sausage 208 1 3.03
Cooked ham 20 6.26
Ham garlic (salami) 33 18 5.20
Hot dog 319 3 2.18
Frankfurter 346 7 0.03
meat pie 137 8 10.66
Pork kebab 218 2 1.24
beacon 75 3 2.05
Luncheon meat 161 2 1.34
Fresh pork meat 146 12 9.09
Kofta 149 2 7.4
Total 132 102 4.86
27
2096

Foods Samples Samples Percent positive
examined positive 0
Goat
Liver 50 0
Spleen
Lymph node 50 0 0
Fresh muscle 52 0 0
662 18 2.89
Total : 814 40 4.91

Foods Samples Samples Percent positive
examines positive
8.75
Sheep 80 7
Mutton, shammi 4.76
kebab 1 0
0
Mutton keema 21 8 6.72

Other products 18

Total : 119

Agarwal (2009)

Foods Samples Samples Percent
examined positive positive

Poultry 76 7 9.21
Dressed frozen
chicken 21 10.04
3 2.52
Poultry meat 209 0
0 0
Chicken-N-ham 119 3 0
0 4.41
Chicken sausage 75 0
2
Chicken salami 81 2 0.62
39 4.76
Chicken kebab 68 3.67

Chicken 37 Agarwal (2009)
frankfurter

Egg 319

Other products 42

Total : 1061

Foods Samples Samples Percent
examined positive positive
Milk/milk product
36 0 0
Raw milk
Dry milk powder 83 3 3.61
Milk chocolate 140 1 0.07
Khoya sweet 5 0
Cheese 51 0 0
315 4 0
Total : 0.12

Agarwal (2009)

E. Coli Prevalence

™ Numerous reports
™ One of the most Important foodborne pathogen in Indian
context

™ Meat and poultry products : 20-50%; up to 100%
™ Human diarrhoea
™ Animal diarrhoea

™STEC (EHEC): Isolations in recent years
™ Animals : Important reservoirs
™ Isolations from meats : Buffalo, sheep, goat, kebabs,
sausages

L. monocytogenes

Source Prevalence Place Reference
Buffalo meat
< 10% Gujarat Brahmbhatt and
Goat meat Anjaria (1993)
< 10% Bareilly Banurekha et al.,
Goat meat (1998)
6.66% Bareilly
Sheep meat 7.4% Bareilly Barbuddhe et al.,
3 - 8% Bombay (2000)
Various meats 8.5% Nagpur Barbuddhe et al.,
produts (2000
Poultry meat Waskar (2005)

Kalorey et al.,
(2005)

I Poultry : Most important transmitters
V ™ Isolations from poultry meat: 20 - 50% up to 100%
R ™ Other meats: 3 - 5%
I

•Pathogen found in aquatic environment

¾Saline & brackish water
¾Drinking water
¾Treated & un-treated sewage
¾ Abattoir waste water
¾Colonize slow sand filters

¾ Fish – Major source

¾ Poultry, Mutton, beef, milk, etc. are also
found to be contaminated

Aeromonas: Prevalence in meats

Source Prevalence Place Reference
Mutton
24-37% Hisar Khurana and
Poultry Kumar (1997)
32-38% Hisar Khurana and
Poultry meat Kumar (1997)
Poultry meat 16% Bareilly Kumar (1998)
Eggs 16% Bareilly Ghatak (2005)

Goat meat 12-22% Bareilly Agarwal (1997)
Various RTE meat Kumar (1998)
products 12% Bareilly Kumar (1998)
14% Bombay
Waskar (2005)

I Hazard
V Characterization
R
I Describes adverse effects of Estimates
particular organism dose –response
relationship
Severity of illness
Morbidity
Fatalities

Scattered reports: No systematic studies on disease
occurrence

™ Prevalence in human (non typhoid) : 1 - 5%
™ Prevalence in healthy carriers: 1 - 2%

L. monocytogenes :
Prevalence in Human

Source Prevalence Place Reference

Abortion (150 patients) 14% Mumbai Krishna et
al., (1966)
Abortion still births 3% -
Bhujwala et
Abortion 3.3% Northern al., (1973)
Abortion 10% India
Kaur et al.,
Nagpur (2007)

Abortion 6% Goa Kalorey
(2008)

Barbuddhe
(2008)

Prevalence of STEC in Human

Source No. of STEC Place Reference
E. coli 9 New Delhi
Diarrhoeal 1338 Pamchandran
patients 19 New Delhi and Verghese
25 18 Bareilly (1987)
HUS patients 240 15 Bareilly Kishore et al.,
67 (1992)
Haemorrhagic Kapoor et al.,
enteritis (1995)
Diarrhoea and Banerjee et al.,
UTI infection (2001) &
Ratore (2000)

I ™ Human diarrhoea: 10 - 15%
V ™ Many asymptomatic carriers
R
I ™ Industrialized countries: Manifestations are severe
™ In Asian countries: Symptoms are milder.

Role in GB syndrome : needs to be explored

• Emerging pathogen of importance : Dairrhoea
• Implicated in extra intestinal infections

Source Prevalence Place Reference
Diarrhoea
Diarrhoea 6.5% Chennai Komathi et
Diarrhoea al., (1998)
8% Kolkata Chaterjee and
Diarrhoea Neogy (1972)
0.2% Vellore Jesudasan and
koshi (1990)
6.5% Bareilly
Ghatak (2005)

• Major cause infant and children diarrhoea
• 100,000 to 150,000 deaths in children

(Broor et al., 2003)

• Prevalence in diarrhoeal cases: 5-71%

– In acute diarrhoea : 20-30%

(Incidence in animal diarrhoea: 10 -50%
( Cattle, goats, sheep, pigs

• Source studies in relation to food: Lacking

– Occurrence in food : difficult to study

Salmonella: Zero Environment:
tolerance in 25 g or Food matrix
ml
L. monocytogenes:
Zero tolerance in 25 g
or ml in USA,
0 –100 in EU/Canada

Dose-response
relationship

Pathogen: Host factor:
Virulence susceptibility
characteristics Immune status

Food Matrix

• Type of food, properties of food, storage conditions
affects growth and survival of pathogen

Salmonella
™ The pH optimum : around neutrality (6.8-7.5).
™ Above 9.0 and below 4.0 being bactericidal.
™ pH values > 10 Salmonella rapidly die.
™ Temperature for optimum growth is 35°C-37°C

ranging between 5°C and 46°C.
As low as 2°C : reported for S. Typhimurium.
™ Freezing arrests growth, but not bactericidal.

Listeria : Relatively sturdy to temperature and pH changes,
survives various processes

Salmonella Characterization

Singh, 2004

Ot hers (75 S. Typ himurium
Sero vars ) 14 %

56 % S. Vircho w
10 %

S. Ent erit id is
5%

S. Welt evred en

5%
S. 3 ,10 :r:-

S. B4a%reilly

S. Anat um 3%

3%

Salmonella serovars in buffaloes

Weltevreden Rough
20% 8%

Typhimurium Bareilly Anatum
8% 45%
2%
Stanley Singh, 2004

2%

Saintpaul

5%

Orion

3%

Lagos

3%

4, 12:i:-

2%

Dublin

2%

Salmonella serovars in Cattle

Weltevreden Rough Adelaide
1% 9% 1%

Typhimurium var Anatum
copenhagan 1%
1%
Berta
Typhimurium 1%
25%
Chester
6%

Drogana
3%

Saintpaul
1%

Rostock
1%

Paratyphi B
1%

Muenchen Dublin
1% 29%

Mbandaka 3, 10 : r : - H3a%vanaEnte4r%itidis Singh, 2004
4% 1%

Heidelberg
1%

Salmonella serovars in Goats

Other 27 serovars Rough
24% 22%

Weltevreden Bareilly
9% 3%

Virchow Dublin
7%
Typhimurium 4%
11%
28 : b : enx
5%

Infantis 4%

Paratyphi B
5%
Saintpaul
Stanley 3%
3%

Singh, 2004

Salmonella serovars in birds

Singh, 2004

Other 34 serovars R1o%ugBhovis2m%orbificaCEnhsaesstbteorur1n%e
1% Enteritidis
12%

Weltevreden 8%
1%

Virchow
14%

Typhimurium Gallinarum
11% 43%

Stanley
2%
Lille
2%Indiana
2%

•Virchow and Typhimurium are more common than Enteritidis.

E. coli

™ Different virulence types

¾ EPEC Frequently reported
¾ ETEC
¾ EIEC Several isolations
¾ EAggEC in recent times
¾ EHEC
¾ DAEC
¾ CDTEC

™ Majority STEC are non O 157: H 7
™ O 157: H 7 : Rare

™ Goat Isolates lack EAE gene: Significance not elucidated

Listeria monocytogenes

• Virulence depends on strain
• Studies on strain/serotype: virulence are available
• 1/2a, 4b serotypes: Implicated in > 90% outbreaks

• Animal Human : Evidence of Zoonoses

Bovine- human reassortants

Porcine –human reassortants

Atypical strains

Antibiotic Resistance

Increased antibiotic resistance of foodborne
pathogens

™ Health related issues associated with resistant
bacteria

¾ Treatment failures
¾ Reduced therapeutic options
¾ Increased severity of symptoms

Resistance profile of Salmonella Virchow

100.00%
90.00%
80.00%
70.00%
60.00%
50.00%
40.00%
30.00%
20.00%
10.00%
0.00%
Ac Cs Ca Ci Do Tr Ak Ce T G Cf N S C K Fr

1986-1990 1991-1995 2001-2005

Cs: Cefoperazone; Ci: Ceftriaxone; Do: Doxycycline; Ce: cephotaxime; T: N= 109
Tetracycline; Cf: Ciprofloxacin; N: Neomycin; K: Knamamycin; Fr: furazolidone

Host Susceptibility

• Exposed population status

– Normal adult
– Infant
– Elderly
– Immuno-suppressed/diseased

• Severity of disease and dose required will
vary

Food Intake/
Exposure Assessment

To consider appropriate food to include in model
Eg: Listeria monocytogenes:

Not linked Low risk Likely risk
Meat/sea foods
Bread, Cookies,
cakes, soft drinks

Cheese/ milk products

Salmonella

I ™ Eggs, poultry meat, pork and other meats and products
V are the common vehicles
R
I ™ Improperly pasteurized fluid milk, ice-cream cheese
and other milk products.

™ Unpasteurized orange juice, uncooked tomatoes, raw
alfa-alfa sprouts, etc.

Characterize range of pathways
by which food is contaminated

I Sources of Salmonella in foods

V ¾ Infected animals
R ¾ Animal excreta, cross-contamination in slaughter houses
I ¾ Contaminated water
¾ Contaminated soil
¾ Rodents, lizards and avifauna

¾ Insects

Prevalence of Salmonellae in common house-
pests/synanthropic animals.

` Agarwal (2009)

I Sources No. examined No. positive (%)
V
R Cockroach 254 4 (1.57)
I House-mouse 97 8 (8.24)
Shrew* 122 12 (9.83)
Fly 31
Bat 48 0
Ant 30 3 (6.25)
Wall-lizard 328 2 (6.66)
910 69 (21.03)
Total :
98

*Triple infection of S. Anatum, S. Hvittingfoss and
S. Saintpaul in one shrew. Double infection of
S. Saintpaul and S. Bareilly in one shrew and that of
S. Typhimurium and S. Paratyphi-B in an another shrew.

Prevalence of Salmonellae in amphibians

Agarwal (2009)

I Sources No. examined No. positive (%)
V
R Snake* 187 16 (8.55)
I
Turtle 26 1 (3.84)

Toad 733 78 (10.64)

*Besides water snakes, these also include 20 cobra
and other land snakes where form no Salmonella
was isolated.

Hazard

+ +identification
Hazard Exposure
characterization assessment

Mathematical models

Risk Characterization

Risk Characterization

• Integration of Hazard identification, Hazard
characterization and exposure assessment
using mathematical models

• To obtain Risk estimates: Qualitative and
Quantitative

• Severity of the adverse effects

• Uncertainties associated with estimates
(biological variations s/a differences in
virulence, susceptibility of population, etc.)

• Based on MRA set the public health goals
and targets

• Appropriate level of Protection (ALOP) is
to be decided by authorities: Eg. Reducing
incidence of Salmonellosis

from To
100 per 1,00,000 10 per 1,00,000

population population

ALOP

• Food Safety Objectives (FSO): The Maximum
frequency and concentration of hazard in food at
the time of consumption that provides ALOP to
consumers
To Achieve ALOP of 10 per 1,00,000 Population
of Salmonellosis

The incidence of Salmonellosis in a particular food
should be brought down to 5% from 10% level

FSO

Avian Influenza

I Hazard Risk
identification Characterization

V
Hazard

R characterization
I Exposure

assessment