VETERINARY PUBLIC HEALTH CENTRE FOR ASIA PACIFIC

Joint Master of Veterinary Public Health_5th Batch, 2011-2013

QUANTIFYING S l ll IN PIG

VIETNAM

QUANTIFYING Salmonella spp. IN PIG

SLAUGHTERHOUSES AND PORK MARKETS

ASSOCIATED WITH HUMAN HEALTH IN HUNG YEN,

VIETNAM

MVPH student: Sinh Dang Xuan (student ID: 541435808)

Advisors: Prof. Dr. Reinhard Fries (FUB)

Dr. Tongkorn Meeyam (CMU)

9/10/2013 1

1. Rational and background

2. Objectives

3. Materials and Methods

4. Results

5. Discussions

6. Conclusions

2

Contents

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39/10/2013

Gram-negative Family Enterobacteriaceae2 Species: S. enterica and S. bongoriSerotypes: > 2,600 (Guibourdenche et al., 2010),

• Typhoidal Salmonella (S.Typhi, S.Paratyphi A, B, C)• Non-typhoidal Salmonella (Food borne pathogens)

Picture source: http://www,odec,ca/projects/2005/qiuc5c0/public_html/Untitled-12,htm 4

Salmonella Microbiology

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-Humans: as a foodborne disease, in the world

93.8 million cases/year

155,000 deaths/year (Majowicz, 2010)

-Health care costs, loss or reduce livestock and

food production

5

Human Salmonellosis

9/10/2013

6http://www.cdc.gov/foodnet/data/trends/tables/2012/table2a-b.html#table-2a

121

155

193

1,082

1,234

2,138

6,793

7,800

0 2,000 4,000 6,000 8,000 10,000

Listeria

Yersinia

Vibrio

STEC

Cryptosporidium

Shigella

Campylobacter

Salmonella

, , , , ,

Human Salmonellosis

Figure 1 Number of laboratory-confirmed bacterial and parasitic infections by pathogens (FoodNet) in 2012

9/10/2013

7

Human Salmonellosis

http://www.cdc.gov/foodborneburden/trends-in-foodborne-illness.html

Figure 2 Changes in incidence of laboratory-confirmed bacterial infections, United States, 2010 compared with

1996–19989/10/2013

Contaminated food/vegetables/fruits (Hughes et al., 2007; Hendriksen et al., 2004; Barber et al., 2002)

Pork: one of major sources of human foodborne after egg and poultry meat (EFSA, 2008)

8

Salmonella in food

Picture source: http://vietpress.vn/201301290235670p46c76/giam-gia-thit-ga-truoc-va-sau-tet.htmhttp://www.xaluan.com/modules.php?name=News&file=article&sid=5272749/10/2013

9

Figure3Estimatedcontributionofbroilers,porkandtableeggsinSalmonellainfectionsinthegeneralpopulation(casesper

100,000)inDenmarkintheperiod1988– 2004

Salmonella in food and Pork

Source: The EFSA Journal (2006), 341, 1-1319/10/2013

10

Table 1 Causes and outbreaks of food poisoning in Vietnam, 2007-2011

Food poisoning outbreaks in Vietnam

Source: VFA, Vietnam, 20129/10/2013

YearCauses for food poisoning outbreaks (in %)

Micro-biological Chemi-cals Natural

toxinsNon-Iden-tification

2007 15 (6.1) 2 (0.8) 54 (21.9) 176 (71.3)2008 16 (7.8) 1 (0.5) 52 (25.4) 136 (66.3)2009 45 (29.6) 8 (5.2) 37 (24.7) 62 (40.5)2010 52 (30.1) 13 (7.8) 59 (35.0) 49 (28.5)2011 40 (28.2) 8 (5.8) 38 (26.8) 56 (39.4)

Average 34 (18.3) 6 (3.5) 48 (21.6) 96 (52.1)

11

Pig slaughterhouses, pork markets and Salmonella contamination

Photo by: Sinh DX9/10/2013

Slaughter equipments

Pigs from farm

Workers/ peopleSH Environment

Market environment

Transportation

Sellers/people

Slaughter water

Water at shop

Shop equipments

Carcass from SH

Transportation

Transportation

FARM

SLA

UG

HTER

HO

US

EM

AR

KET

HOME

-15% - 95%: on carcasses

-16% - 62%: in water, on the floor, weighting

bowls, cutting boards

-33% - 69%: in pork at market

(Le Bas, 2006; Takeshi K,2009)

12

Salmonella contamination in slaughterhouses and market in Vietnam

9/10/2013

139/10/2013

To detect the Salmonella spp. prevalence and concentration on pig carcass at slaughterhouse and pork at market

To identify risk factors of Salmonella spp. contamination in the pork production chain

To explore people’s and relevant stakeholders perception related to Salmonella contamination with the potential risks in practice

14

Objectives of study

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159/10/2013

Hung Yen province

16

Map of Vietnam

Source: http:/www, trelangkienviet,com

5

Study location

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179/10/2013

Study location

18

Study scope

Datacollection‐ Checklist‐ Questionnaire‐ Focusgroupdiscussion(FGD)‐ In‐depthinterview(IDI)

Dataanalysis

Samplecollection

Salmonella identification(ISO6579:2002/Amd

1:2007)

Salmonellaquantification(3‐TubeMPNmethod)ISO21528‐1:2004

Carcass Pork Environmentalswabs(Ccuttingboard,Hands)

3PigSlaughterhouses&Markets(4visitseach)

Study duration: From January to May, 2013

9/10/2013 Figure4Studyscopeandprocess

19

Sampling site

Lairage

Evisceration

Restrain & Bleeding

Cut pork at market

9/10/2013

Scalding & Dehairing

Transportation

FARM

SLAUGHTER-HOUSE

MARKET

Washing & wiping

Splitting

Transportation

Carcass

Workers hands

Cutting board

Cutting board

Pork

Sellers hands

HOME Pork at household

Transportation

Sample collection

20

Sample types Unit/sample n

Carcass surface 400 cm2 47Belly skin 25 g 16

Workers’ hand 2 hands 12

Cutting board 25 cm2 12Pork 25 g 63Sellers’ hand 2 hands 12Cutting board 25 cm2 12

Total 174

Table 2 Number and types of sample collection

9/10/2013

25gBellyskinorPork

CarcassorEnvironmentalswabs

Homogenization+225mlBPW +100mlBPW

InterpretationofResult

Suspectedcolonieson

NA

Biochemical&SerologicalConfirmation

Microbiological Analysis

21Figure 5 Salmonella identification and quantification

Salmonella quantification

10‐1 10‐2 10‐31ml

9mlMKTTn

3drops

MSRV MSRV

Salmonella identification

XLT4 BGA XLT4 BGA

3‐tubeMPNmethod

9/10/2013

Questionnaire: - No. of pigs- Transport time, duration, distance- Time in lairage, …

Checklist: - Hygienic practice/measures- Biosecurity

22

Data collection

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23

Data collection

9/10/2013

Qualitative tools

Focus group discussion Key topics

Slaughter workers (2 FGD)

- Hygienic practice in slaughtering - Perception, knowledge about pork borne diseases

Pork sellers (3 FGD) - Pork selling practice- Pork borne diseases (knowledge, awareness, perception)

In-depth interview

People living around slaughterhouse (9 IDI)

- Advantages and disadvantages of slaughterhouse

Pork consumer (9 IDI) - Criteria for selecting pork - Pork borne diseases (knowledge, awareness, perception)

Public health staff (3 IDI) Food safety and zoonotic management & collaboration

Veterinary staff (3 IDI) Food safety and zoonotic management & collaboration

FGD = Focus Group Discussion; IDI = In-depth interview

- Descriptive statistic

- OR and χ2 test for risk factors

- Significant consideration at p<0.05

Using R Studio (0.96.316) and MS Excel-2007

24

Data analysis

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259/10/2013

General information of slaughterhouses

Table 3. Mean of variables recorded from pig transportation and lairage time (n=12 visits)

Variables Unit Mean ± SD Range

No. of pig transport/time Head 23 ± 7 17 - 40

Transport duration Hour 1.76 ± 1.24 0.5 – 4.17

Transport distance Km 60.8 ± 50.4 15 – 150

Resting time in lairage Hour 13.1 ± 4.17 5 - 17

SD= Standard deviation

Capacity: 10-40 pigs/day; 4-6 workers; slaughter: 1-5 a.m

269/10/2013

27

SampletypesPrevalence_%

(No. positve result/n)SHA SHB SHC Overall

Carcass(*) 23.8(5/21)

38.1(8/21)

42.9(9/21)

34.9(22/63)

Workers’ hand 25.0(1/4)

100(4/4)

25.0(1/4)

50.0(6/12)

Cuttingboard 25.0(1/4)

50.0(2/4)

25.0(1/4)

33.3(4/12)

Overall 24.1(7/29)

48.3(14/29)

37.9(11/29)

36.9(32/87)

Table 4. Salmonella prevalence from different sample types in 3 slaughterhouses

Salmonella prevalence

(*) include swab and belly skin, SH= Slaughterhouse

9/10/2013

Fig 6. Overall Salmonella prevalence from 3 slaughterhouses

24.1

48.3

37.9

0

10

20

30

40

50

60

SHA SHB SHC

Percent

Slaughterhouse

28

Salmonella prevalence

No significant difference (p=0.403, χ2 test) among 3slaughterhouses

9/10/2013

29

Table 5. Salmonella prevalence from different sample types in markets

Salmonella prevalence

9/10/2013

Sample type% Prevalence (No. Salmonella positve/n)

District A District B District C Overall

Pork 14.3 (3/21)

47.6 (10/21)

66.7 (14/21)

42.9 (27/63)

Sellers’ hands 25.0 (1/4)

0.0(0/4)

75.0 (3/4)

33.3 (4/12)

Cutting board 25.0 (1/4)

25.0 (1/4)

75.0 (3/4)

41.7 (5/12)

Overall 17.2(5/29)

37.9 (11/29)

69.0 (20/29)

41.4 (36/87)

30

Fig 7. Salmonella prevalence from different sample types in markets

Salmonella prevalence

9/10/2013

17.2

37.9

69.0

01020304050607080

District A District B District C

Pork markets

Perc

enta

ge

Statistically significant difference about Salmonella prevalence on pork samples among 3 districts (p-value=0.0018, Fisher’s exact test)

23.5

46.7

53.3

34.9

14.3

47.6

66.7

42.9

0

10

20

30

40

50

60

70

District A District B District C Overall

Carcass Pork

31

Fig 8. Salmonella prevalence on carcass in slaughterhouses and on pork in markets in 3 districts

Salmonella prevalence

9/10/2013

Perc

enta

ge

Salmonella prevalence

Salmonella number

Table 6. Salmonella number from different sample types in 3 slaughterhouses

Sample types Unit No. of Salmonella 95% CI

Carcass surface MPN/cm2 <0.075 0.0-0.24

Belly skin MPN/g <0.3 0.0-0.95

Workers’ hand MPN/hand 7.0 1.0-50.0

Cutting board MPN/cm2 <1.2 0.0-3.80

329/10/2013

Salmonella number

Sample types Unit No. of Salmonella 95% CI

Pork MPN/g < 0.3 - 15 3.7 - 42.0

Sellers’ hands MPN/hand 4.6 0.7 - 19.0

Cutting board MPN/cm2 0.368 0.056 - 1.52

339/10/2013

Table 7. Salmonella number from different sample types in markets in 3 districts

Salmonella number

Table 8. Salmonella number in slaughterhouse and market

349/10/2013

Sample UnitNumber of Salmonella

Slaughterhouses Markets

Carcass - Pork MPN/g < 0.3 < 0.3 - 15

Worker - Seller hand MPN/hand 7.0 4.6

Cutting board MPN/cm2 < 1.2 < 0.368

35

Related risk factorsTable 9. Potential risk factors related to Salmonella

contamination in slaughterhouses

Potential risk factors of Salmonella contamination were not found significantly diference.

CI: Confident interval

9/10/2013

Factors OR (95% CI) p -Value

Using water tank 2.18 (0.67-7.07) 0.191

Slaughter square area (≤ 50 m2) 1.67 (0.57-4.95) 0.350

Free entry slaughter area 2.18 (0.67-7.07) 0.191

Private farm type 2 (0.29-13.74) 0.631

Pig transport distance (> 30 km) 1.33 (0.2-9.08) 1.00

Time arrived at lairage in the morning 5.7 (0.53-61.41) 0.179

Disease in farm area (in 6 months recently) 10.5 (1.03-107.2) 0.063

Number of pigs on processingat the same time (>2 pigs) 1.2 (0.41-3.66) 0.709

36

Related risk factorsTable 10. Potential risk factors of Salmonella contamination in markets

(*) Statistically significant diference. CI: Confident interval

9/10/2013

Observation OR (95% CI) p-value

Table surface pork contacted is wood 6.6 (2.02 - 21.55) 0.002*

Table surface pork contaced is inox/steel 0.19 (0.02 - 1.7) 0.223

Usually use insect control equipments while selling 1.76 (0.6 - 5.23) 0.303

Using meat grinder 2.41 (0.8 - 7.22) 0.113

Using bucket (mobile) water in shop 4.46 (1.46 - 13.65) 0.007*

Cutting on table surface 4.46 (1.46 - 13.65) 0.004*

Shop sells retail only 0.48 (0.17 - 1.38) 0.170

Shop sells both retail and wholesale 4.71 (1.28 - 17.27) 0.030*

Contain pork in basket to transport to the shop 2.8 (0.98 - 8) 0.052

Wash table end of selling time by water and detergent 0.44 (0.1 - 1.84) 0.326

37

Salmonella serotypes

9/10/2013

Table 11. Salmonella serotypes circulated in 3 pig slaughterhouses and sample types

Serotype Carcass Workers hands

Cutting board Total Percentage

S. Anatum 1 1 3.2S. Derby 3 2 1 6 19.4S. Give 1 1 2 6.5S. London 4 4 12.9S. Meleagridis 2 1 1 4 12.9S. Rissen 2 2 1 5 16.1S. Typhimurium 5 1 6 19.4S. Weltevreden 3 3 9.7

Total Poly I 31 100Poly II 1

38

Salmonella serotypes

9/10/2013

Fig 9. Salmonella serotypes distribution in 3 pig slaughterhouses

S. Anatum3.2%

S. Derby19.4%

S. Give6.5

S. London12.9%

S. Meleagridis 12.9%

S. Rissen16.1%

S. Typhimurium19.4%

S. Weltevreden9.7%

39

Salmonella serotypes

9/10/2013

Table 12. Salmonella serotypes circulated in marrkets in 3 districts and sample types

Serotype Pork Sellers hands

Cutting board Total Percentage

S. Anatum 4 1 1 6 16.7S. Bovismorbificans 1 1 2 5.6S. Derby 6 1 7 19.4S. Give 1 1 2.8S. London 4 1 5 13.9S. Meleagridis 4 1 1 6 16.7S. Rissen 4 1 5 13.9S. Stanley 2 2 5.6S. Weltevreden 2 2 5.6

Total 36 100

40

Salmonella serotypes

9/10/2013

Fig 10 Salmonella serotypes distribution in markets in 3 districts

S. Anatum 16.7%

S. Bovismorbificans

5.6%

S. Derby19.4%

S. Give2.8%

S. London13.9%

S. Meleagridis16.7%

S. Rissen13.9%

S. Stanley5.6%

S. Weltevreden5.6%

41

Salmonella serotypes

9/10/2013

Fig 11 Salmonella serotypes distribution in Slaughterhouse and in Markets in 3 districts

16.7

5.6

19.4

2.8

13.9

16.7

13.9

5.65.6

S. Anatum S. BovismorbificansS. Derby S. GiveS. London S. MeleagridisS. Rissen S. StanleyS. Weltevreden

Markets

3.2

19.4

6.5

12.9

12.9

16.1

19.4

9.7

S. Anatum S. DerbyS. Give S. LondonS. Meleagridis S. RissenS. Typhimurium S. Weltevreden

Slaughterhouse

42

Salmonella serotypes

9/10/2013

Fig 12 Salmonella serotypes distribution in slaughterhouse and markets

1

3

1

4

2

2

5

3

3

1

2

3

1

4

6

1

4

4

4

2

2

2

2

1

1

2

1

0 2 4 6 8 10 12 14

S. Anatum

S. Bovismorbificans

S. Derby

S. Give

S. London

S. Meleagridis

S. Rissen

S. Stanley

S. Typhimurium

S. WeltevredenPig carcass at SHEnvironment at SHPork at MKEnvironment at MK

43

Collected Data Frame

9/10/2013

Table 13 Groups and participants for IDI, FGD, checklists & questionnaires

Tools/ groups/stakeholders/places

No. groups /districts

Total participant/interviewee/checklist

Quantitative QuestionnairePig origin questionnaire (slaughterhouse owner)

3 12

Observation (checklist)Pig slaughterhouse 3 3Pork shop 3 19

QualitativeFocus group discussionSlaughter worker 2 10Pork seller 3 15

In-depth interviewPeople living around slaughterhouse 3 9Pork consumer 3 9Public health staff 3 3Veterinary staff 3 3

FGD = Focus Group Discussion; IDI = In-depth interview

44

Results from explore people and relevant stakeholders’ perception

related to food safety with the potential risks in practice

9/10/2013

* Focus groups discussions in Slaughterhouse workers

1. Regulation: No specific regulation or rule, used “internal rule”

2. Training program on food safety and slaughtering process: learning by

doing, not officially from training

3. Perception, knowledge about pig diseases: FMD, PRRS, fluke and worm,

pigs diarrhea: Two main important: FMD and PRRS

4. Zoonoses knowledge and perception: cysticercosis and leptospirosis, but

were not really concerned. FMD and PRRS: misperception

5. Origin of information: mass media, newspaper, internet or TV. Vet and

or public health services were not mentioned

6. Observed human illness related pig or pork: No observed cases of

illness or diarrhea in last 6 months.

459/10/2013

* Focus groups discussions in Slaughterhouse workers

Potential risks District A District B

Feces in lairage 1 7

Feces on live pigs 1 3

Puncture intestine 2 2

Feces on the bleeding area 2 4

Wash intestine at slaughter areas 2 5

Water source 3 1

Boots at all places 6 7

Transport vehicle 7 9

Cloths 5 8

Table 14 Ranking given potential risks to microbial contamination on carcass

469/10/2013

* Focus groups discussions in Pork sellersFGD for this actor were organized in each of 3 selected districts

1. Prefer to use wood surface tables in pork shop: in stead of other types

2. Cloth usually used to dry pork, clean equipment, hand or table: All three

sellers groups stated using during selling time

3. Glove and mask using: a perception to buyers aware of sellers’ health

problem.

4. Leftover pork: sell it for the shop at a relatively lower price, processed into

other foods

5. Pork quality and zoonoses: pork quality related to the way slaughtered pig

* PRRS and FMD, CSF, pastuerellosis, leptospirosis, cysticercosis

Misperception on FMD, CSF

6. Observed human illness related pig or pork: None of the participants

479/10/2013

* Focus groups discussions in Pork sellers

Potential risks District A District CCleanness of surrounding shop area 1 4

Insects (files, bluebottle, ant, cockroach) 2 5

Dirty /waste water drain next to shop 2 2

Cleanness of table surface 3 1

Water for wash hand, knife, table 4 4

Bags - Basket (pork transport) 5 3

Cloths used many times in selling day 6 2

Pork transportation to the market 7 3

Clothes, shoes of sellers 8 6

Table 15 Ranked potential risk factors related to microbial contamination on pork at market

489/10/2013

* In-depth interview in People living around slaughterhouse

(1) Advantages of slaughterhouse’s presence in their living area:

Issues All District A District B District C

Provide job 9/9 3/3 3/3 3/3

Available pork to buy 7/9 1/3 3/3 3/3

Business opportunities 4/9 0/3 1/3 3/3

Benefit for you 0/9 0/3 0/3 0/3

Table 16 Advantages of slaughterhouse’s presence (Yes/Total)

499/10/2013

* In-depth interview in People living around slaughterhouse

(2) Disadvantages of slaughterhouse’s presence in their living area:

Issues All District A District B District CNoise 0/9 0/3 0/3 0/3Polluted environment 1/9 1/3 0/3 0/3Dust 1/9 0/3 1/3 0/3Polluted air 2/9 2/3 0/3 0/3

Flies/Mosquitoes 2/9 0/3 1/3 1/3Smell 3/9 1/3 0/3 2/3Polluted water 3/9 2/3 0/3 1/3

Animal disease spread 3/9 2/3 0/3 1/3

Health effect 5/9 2/3 1/3 2/3

Table 17 DisaAdvantages of slaughterhouse’s presence (Yes/Total)

509/10/2013

* In-depth interview in Pork consumers

Table 18 Result of criteria ranking in pork selection

Criteria No. of respondents Mean ± SDBright red, soft and sticky 9 9.6 ± 0.7Freshness, good smell 9 9.6 ± 0.5Cleanness 9 9.1 ± 0.8Trust on seller 9 9 ± 1.1Considered as safe meat 9 8.9 ± 0.9Good storage 9 8.6 ± 1.8Nutritional value 9 8.2 ± 2.0Pork inspection document 9 8 ± 1.7Accessibility 9 7.4 ± 1.7Price 9 6.6 ± 1.1

519/10/2013

* In-depth interview in Pork consumers

(2) Perception on low quality pork: sick or dead pigs, strange color,

smell badly or look wet.

(3) Knowledge on zoonoses: Mentioned at least one zoonotic disease:

such as cysticercosis, leptospirosis, anthrax, streptococcus suis

or diarrhea in pig.

(4) Observed human illness related pig or pork: no cases of illness or

diarrhea were observed in the recent 12 months.

529/10/2013

* In-depth interview Public health staffs

(1) Responsibilities related to food safety, zoonoses: Responsibilities

were on “cooked food”; apply the regulation, observe, training,

guide on food safety and hygienic practice.

(2) Collaboration on food safety, zoonoses management:

• Reporting and updating within sector or district authorities and

upper level

• Collaboration with with other sectors: was better and uniformed,

still need for further strengthening

539/10/2013

* In-depth interview Veterinary staffs

(1) The gap in the inspection: Vets and Public health sector: Raw meat

and cooked food.

• Inspection duties in big or medium slaughterhouses, not frequent

in small/private

(2) Collaboration on food safety, zoonoses management:

• Collaboration_A task force team: Public health, commercial, trade

management, veterinary, environment, police, etc…

• Task force team: situation or “problem base” or “Food safety action

month”

• Collaboration among professional sectors: more effective, still

needs to improve, action plan, good mechanism.

549/10/2013

55

Salmonella prevalence in pig slaughterhouse

9/10/2013

* On pig carcasses (34.9%)

Lower than in other studies:• 48.9% (Thai, 2007) - Vietnam• 95.7% (Le Bas, 2006) - Vietnam• 55.5% (Sanguankiat et al., 2010)- Chiang Mai, Thailand• 36.7% (Sithigon, 2011) - Northestern Thailand

Higher than in other studies:• 33.2% (Fries, 2006)- Northern Thailand• 11.7% (Algino et al., 2009)- USA• 11.2% (Korsak et al., 2003) Belgium• 8.3% (EFSA, 2008) - in the EU- State members

* Worker hand (50%): 10.7% Khon Kean-Thailand (Sithigon. D, 2011)

* Cutting board (33.3%): 47.4% Hue–Vietnam (Takeshi et al., 2009)

569/10/2013

* On Pork (42.9%)

Lower than in other studies:• 69.9% (Phan et al., 2005) in Mekong Delta, Southern Vietnam

• 65% (Angkititrakul, 2005) in northeast Thailand

Higher than in other studies:• 32.8% (Takeshi et al., 2009) in Hue - Vietnam

• 39.6% (Thai et al., 2012) in Northern Vietnam

• 34.5% in retail pork (Sanguankiat, 2010) Northern Thailand

• 0.3% to 4.3%. (Delhalle et al., 2009) in Belgium

* Cutting board (33.3%): 28.6% Hue–Vietnam (Takeshi et al., 2009)

Salmonella prevalence in pork market

57

Salmonella number in pig slaughterhouse

9/10/2013

* On pig carcasses (< 0.075 MPN/cm2 and <0.3 MPN/g)

Within a range of <0.03–0.36 MPN/g

Ireland (Prendergast, 2008)

From: -3.40 ± 2.04 log CFU/cm2 carcass

Belgium (2009) (Delhalle et al., 2009)

* Cutting board (< 1.2 MPN/cm2):

Conveyor and table swabs ranging from <0.03–1.1 MPN/cm2

Ireland (Prendergast, 2008)

The low numbers of Salmonella cells were typically found in

food, feed and environment samples (Boughton, 2004)

58

Salmonella number in pork market

9/10/2013

* On pork (< 0.3 – 15 MPN/g)

Lower range than:

19 MPN/g in pork sausages

0.03 to >110 MPN/g, with a mean value of 21.16 MPN/g

Italy (Bonardi et al., 2008)

Higher range than:

Below 10 MPN/g, Germany (Sinell et al., 1990)

Between <0.03 - 2.10 MPN/g, Ireland (Prendergast, 2009)

From: -2.64 ± 1.76 log CFU/g, Belgium (Delhalle et al., 2009)

Transport and lairage: important risk factors (Hurd, 2002)

Characteristics of farms/herds is one of consideration as high-risk herds (Fosse, 2008)

Floor as an important source of pathogens including Salmonella (Hald, 1999)

Evisceration has been described in Europe as the major cause of carcass contamination (Berends et al., 1997)

Risk factors of Salmonella contamination in slaughterhouse

599/10/2013

Not found significant differences among potential risk factors in slaughterhouses

A direct association between Salmonella contamination of pork cuts and equipment or/and surfaces (Prendergast et al., 2008)

The most important parameter with regard to contamination were handling, general hygiene, time and temperature at each stage (Wong et al., 2002)

Hygiene performance, particularly at retail, had a significant impact on the occurrence of Salmonella (Hansen, et al., 2010)

Risk factors of Salmonella contamination in marrket

609/10/2013

Wood table surface, using bucket water, cutting on table surface and selling both retail and wholesale

61

Salmonella serotypes prevalence in slaughterhouse

9/10/2013

8 serotypes: S. Typhimurium and S. Derby (19.4%), S. Rissen(16.1%), S. London, S. Meleagridis (12,9%); S. Give, S. Anatum, S. Weltevreden (3.2-9.7%)

S. Typhimurium (20.7%), S. Weltevreden, (15.3%), S. Derby (11.7%) and S. Rissen (11.7%) (Vo, 2006) - Vietnam

S. Derby (41%) and S. Typhimurium (29%) (van Hoek et al., 2012)-Netherlands

S. Typhimurium and S. London were the most common of the 24 serotypes (Schmidt et al., 2012) – US

62

Salmonella serotypes prevalence in market

9/10/2013

9 serotypes: S. Derby (19.4%), S. Anatum and S. Meleagridis(16.7%), S. London and S. Rissen (13.9%), S. Bovismorbificans, S.Give, S. Stanley and S. Weltevreden (2.8 – 5.6%)

S. Anatum (19.8%), S. Derby (15.9%), S. Typhimurium (13.5%), except S. Infantis (13.5%), S. Reading (7.9%), S. Newport (6.3%) (Thai et al., 2012) – Northern Vietnam

S. Derby, S. Weltevreden, and S. London in pork, S. Bovismorbificansin retail meat (Phan et al., 2005)- South Vietnam

S. Rissen (61.5%), S. Stanley and S. Lexington (11.5%). (Angkititrakul et al., 2005)- Thailand

S. Derby, S. Anatum, S. Typhimurium, and S. Schwarzengrund (Chen et al., 2006)- Taiwan

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Salmonella serotypes prevalence in market

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9 serotypes: S. Derby (19.4%), S. Anatum and S. Meleagridis(16.7%), S. London and S. Rissen (13.9%), S. Bovismorbificans, S.Give, S. Stanley and S. Weltevreden (2.8 – 5.6%)

• S. Typhimurium is a serotype predominantly and followed by S.

Enteritidis and S. Weltevreden isolated from humans in Vietnam (Vo et

al., 2006)

• PFGE: S. Derby was detected in 19% of strains from humans, 52%

from food (include pork products), and 62% from swine in Spain

(Valdezate et al., 2005)

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Perception related to food safety with the potential risks in practices

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• Applied an integrated approach: Quantitative (Salmonella

contamination) and qualitative (FGD, IDI) – hasn’t been applied before

• Improvement of the practices could considerably reduce the carcass

contamination.

- Using gloves (not used) => found hight prevalence on hands

- Using cloth to wipe => habor of Salmonella !?

- “Trained by doing”=> standard information and training

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Perception related to food safety with the potential risks in practices

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• Using wooden tables because of their perception that meat looks

longer fresh => still prefer to use it

This gap is currently addressed by the Livestock Competitiveness

and Food Safety Project (LIFSAP) of government.

=> The LIFSAP project plans also to upgrade facilities in selected

open fresh food markets and slaughterhouse. (ILRI, 2010b).

- Enhance facilties and good hygiene practice in slaughterhouse

- Investment replacing wooden tables by stainless steel ones

- Providing pork retailers with hangers to hang carcass, etc.

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Perception related to food safety with the potential risks in practices

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• Important selection criteria for purchasing pork: fresh pork (Lapar et

al., 2009)

• Price has lowest important, but a study in Germany, price was

important (Rohr et al., 2005)

• Our finding related to zoonoses revealed that almost all actors had little

knowledge or some misperception on zoonoses in agrement with

ongoing study in Vietnam (Hung et al., 2012).

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Prevalence of Salmonella:

36.9% in slaughterhouse, 34.9% on carcass

41.4% in pork markets, 42.9% in pork

The number of Salmonella:

< 0.075 MPN/cm2 on carcass

< 0.3 to 15 MPN/g on pork

Potential risk factors of Salmonella contamination:

In pig slaughterhouses: not found

In pork in market: wood table surface, bucket water, cutting

on table surface, selling both retail and wholesale.

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Conclusion

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The most frequent Salmonella serotypes:

In slaughterhouse:

S. Typhimurium, S. Derby (19.4%),

S. Rissen (16.1%) , S. London, S. Meleagridis, S

(12.1%). Weltevreden, S. Give and S. Anatum

In market:

S. Derby (19.4%), S. Anatum, S. Meleagridis (16.7%),

S. Rissen, S. London (13. 9%),

S. Bovismorbificans, S. Give, S. Weltevreden.

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Conclusion

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The survey on perception and hygienic practice related to

food safety of relevant groups and stakeholders:

Provided basic information and contribute a better understanding

of their practice.

Require of standards and targeted training for slaughter workers

and pork sellers.

Help to better engagement in management on groups, actors in

pork production chain.

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Conclusion

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719/10/2013

Acknowledgement

Veterinary Public Health Center for Asia Pacific (VPHCAP) - CMU

and Freie Universität Berlin

USAID (the EPT/RESPOND program), Hanoi School of Public

Health (HSPH), CENPHER (HSPH), Eco Health One Health

Resource Center, CMU and International Livestock Research

Institute (ILRI, EcoZD project)

Dr. Fred Unger (ILRI) and Assoc. Prof. PhD. Nguyen Thanh Huong

(HSPH)

Slaughterhouse owners, workers, pork sellers and local veterinary

staffs in Hung Yen

Department of Veterinary Hygiene-NIVR (Vietnam)

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