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Risk for Vibrio and Paragonimus infection linked to crab and

shrimp consumption in Abidjan and Dabou (Côte d’Ivoire)

Traoré S.G., Bonfoh B., Odermatt P., Utzinger J., Aka N.D., Adoubryn K.D., Assoumou A., Dreyfuss G., Koussémon M.

ICOPHAI 15th-17th september 2011_Ethiopia

Introduction (1)

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Paragonimiasis

• Neglected tropical disease caused

by lung flukes of the genus

Paragonimus

• Often confused with tuberculosis

(similar symptoms, e.g. chronic

cough, haemoptysis)

• 21 million people are currently

infected

• 11 out of 48 species are human

pathogenic

Introduction (2)

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Paragonimiasis: geographic distribution

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Introduction (3)

Vibrio infections (cholera and others)

• Consumption of raw or undercooked seafood and contaminated water

• 12 species out of 90 are human pathogenic (V. cholerae, V. parahaemolyticus, V. vulnificus, V. mimicus, V. alginolyticus)

• Lack of data on food-borne illness due to consumption of shellfish in Côte d’Ivoire

• The true incidence of diseases transmitted by fish products is not known since the reporting of food-borne illnesses is not mandatory

• No sanitary control measures in place for shellfish obtained from traditional fishing

Hypothesis

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• Among patients of TB centres and children, there are some cases of paragonimiasis because of the lack of differential diagnosis between these two diseases and undercooking crabs by the children on the site of fishing.

• Shellfish sold in local markets would be contaminated with Vibrio, due to the increased concentration of bacteria in coastal waters resulting in global warming • Except Paragonimus africanus and P. uterobilateralis recognized in Côte d’Ivoire, other species of Paragonimus exist in this country and increase the rate of infection of crabs • The emergence of paragonimiasis and Vibrio infection are the result of sociocultural factors

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Objectives

General objective

• To assess the health risk from consumption of shellfish sold on local markets in Côte d’Ivoire

Specific objectives

• To determine the prevalence of paragonimiasis among patients attending tuberculosis centres and among schoolchildren

• To determine the prevalence of Paragonimus and Vibrio in crabs and shrimps

• To characterize metacercariae of Paragonimus and strains

of Vibrio that are isolated from crabs and shrimps

• To describe consumption habits of shellfish considered likely to influence the risk of infection with Vibrio and Paragonimus

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Methods (1)

Study area

(A) Côte d’Ivoire (B) Abidjan

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Methods (2)

Survey Sample size Methods Site of sampling

Looking for

metacercariae of

Paragonimus in shellfish

Concentration

technique

1 market in Dabou and 6

markets in Abidjan

Looking for Vibrio in

shellfish

322 Bacteriological analysis,

MALDI-TOF, PCR

1 market in Dabou and 6

markets in Abidjan

Looking for eggs of

Paragonimus in sputum

and stool of TB centres

patients

332 Ritchie technique TB centres of Treichville and

Adjamé (Abidjan)

Looking for BK in sputum

of TB centres patients

332 Auramine technique TB centres of Treichville and

Adjamé (Abidjan)

Looking for eggs of

Paragonimus in stool of

schoolchildren

269 Kato-Katz and Ether

concentration technique

Allaba and N’Gatty (Dabou)

Households survey on

shellfish consumption

120 Questionnaires 10 boroughs of Abidjan

• Authorization from National Ethics Committee

• Inventory of shellfish production and marketing system of shellfish

272

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Results (1)

Prevalence of 7.8% of Vibrio spp. infection in shellfish

Shellfish No. of specimens

examined

No. of specimens

infected

% infected

(95% CI)

Shrimps of the genus Penaeus

spp. 112 16 14.3 (8.4-22.2)

Crabs of the genus Callinectes

spp. 150 9 6.0 (2.8-11.1)

Shrimps of the genus

Macrobrachium spp. 40 0 0

Crabs of the genus Cardisoma spp. 20 0 0

TOTAL 322 25 7.8 (5.1-11.2)

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Results (2)

Species of Vibrio

identified

No. of species identified from shellfish

Crabs

Callinectes

Crabs

Cardiosoma

Shrimps Total % of all

V. alginolyticus

6

0

4

10

40

V. parahaemolyticus 2 0 6 9 36

V. cholerae non O1; non O139 1 0 5 6 24

Total 9 0 16 25 100

25 species of Vibrio characterized by PCR with 40% of Vibrio alginolyticus and the genes encoding virulence factors of Vibrio

cholerae and Vibrio parahaemolyticus were not found

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Results (3)

Crustacean genus

No. of crustacean

examined

No. of crustacean

infected Prevalence (%)

Crab Callinectes 221 30 13.6

Crab Cardiosoma 18 2 11.1

Shrimp Penaeus 30 0 0

Shrimp Macrobrachium 3 0 0

Total 272 32 11.8

Prevalence of 11.8% of metacercariae of trematodes in shellfish

Results (4)

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5 4.2 2.5

30.8

55

2.5

0

10

20

30

40

50

60

5-15 15-30 30-45 45-60 More 60 Unknown

11.67

45.8342.5

0

5

10

15

20

25

30

35

40

45

50

Every day Occasionally Rarely

Percentage of households

Estimated time of cooking shellfish (min) Frequency of consumption of shellfish

Signs and symptoms (diarrhoea, stomach ache) potentially associated with food poisoning due to the consumption of shellfish as porridge were reported by 7.5% of the interviewees

Results (5)

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• Not a single Paragonimus spp. infection was found among the patients and the schoolchildren

• 27.7% of patients of TB centres were infected with at least one helminth or intestinal protozoon

• 22.3% of patients of TB centres were diagnosed with pulmonary tuberculosis, with higher prevalence in males than females (28.8% vs. 13.9%, p =0.03)

• 34.9% of schoolchildren were infected with at least one helminth or intestinal protozoon, with higher prevalence of helminth infections in boys than girls (32.9% vs. 8.3%, χ2 = 14.30, p <0.001).

Conclusion and recommendations

• Shellfish constitutes an important part of the dietary protein in Côte d’Ivoire

• These products are infected with metacercariae of trematodes and non virulent Vibrio (V. alginolyticus, V. parahaemolyticus and V. cholerae non O1; non O139)

• The risk of paragonimiasis and Vibrio infection is low among the population at risk (schoolchildren, TB patients, consumers)

• Differential diagnosis between paragonimiasis and pulmonary tuberculosis must be done by the medical doctors in TB centres

• People must properly cook shellfish for at least one hour at 100°C because the change in colour does not mean that the product is cooked

• Cross-contamination between raw shellfish and ready-to-eat foods must be avoided

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Acknowledgements