Analyse des risques microbiens du lait cru local à Abidjan (Côte d’Ivoire)

The hygiene practices during milking, the microbiological and chemical quality of cow raw milk from production to sale were studied in 15 small dairies in Abidjan. The analysis of raw milk quality showed that 81.5% of raw milk taken udders of cow were of good quality, against 35.30% for raw milk on sale. The average of Coliforms was 8.7.103 cfu/ml for raw milk taken cow’s udder, 3.2.105 cfu/ml for raw milk in tank and 9.9.105 cfu/ml for raw milk sales. The udders of cows, hands of milkers were identified as primary sources of milk contamination. The utensils (farmer, vendor) and environment were identified as major sources of secondary contamination. In addition, 24.7% of milk contained antibiotics and 50% of raw milk on sale were wet with water. The occurrence of food borne diseases is significantly related to the behavior of consumption of unpasteurized raw milk (P<0.05) with a relative risk of 2.81 (95%CI: 1.17 – 6.78). The zootechnical management of actors and popularization of good hygiene practices throughout the production chain are necessary for improvement of local milk quality

Valeur ajoutée de la participation à l'analyse des risques des produits d'origine animale vendus dans le secteur informel

La sécurité sanitaire des aliments est devenue, durant les deux dernières décennies, une préoccupation majeure des consommateurs, des autres acteurs des filières agro-alimentaires et des décideurs. Cela est le résultat d’un regard plus attentionné sur la qualité des aliments à la suite des différentes crises et intoxications alimentaires ayant engendré en plus des souffrances, des pertes en vies humaines. Les mesures de contrôle des risques sanitaires sont encore insuffisantes du fait de la non maîtrise des facteurs de risques et de la complexité dans l’application de la méthode classique d’épidémiologie quantitative d’analyse de risques dans la chaîne de valeur alimentaire. Par ailleurs, ces analyses des risques se limitent au stade initial d’identification du danger. En s’appuyant sur des études de cas réalisées en Afrique subsaharienne au niveau du secteur informel du lait et de la viande et fruits de mer (Côte d’Ivoire, Ethiopie, Mali et Nigeria), nous démontrons que la participation des acteurs et la prise en compte de leurs connaissances peuvent contribuer à une analyse mieux élaborée des risques alimentaires. Les approches participative et transdisciplinaire se révèlent être d’une grande efficacité dans la collecte d’importantes données qualitatives complexes pour expliquer les données biologiques quantitatives (exposition, dose-effet). Elle pourrait permettre par une association de plusieurs techniques de collecte des données (enquête par questionnaire, Méthode Accélérée de Recherche Participative (MARP) et Focus Group Discussion), de réduire les coûts de l’analyse du risque et de mieux préciser le risque pour les prises de décisions pertinentes dans le secteur informel des denrées alimentaires d’origine animale Food safety has become over the last two decades a major concern for consumers and other stakeholders in food value-chain, as well as decision makers. This has resulted in more attention on quality, augmented by various recent food poisoning crises and resultant suffering and human life losses. The control measures of health risks remain inadequate due to the complexity of applying classical quantitative epidemiology on risk analysis in the food value-chain. Furthermore, risk analysis is still limited to the initial stages of hazard identification. Based on case studies in Sub-Saharan Africa in the informal sector of milk, meat and see food (Côte d'Ivoire, Ethiopia, Mali and Nigeria), we demonstrate that stakeholder participation and incorporation of their knowledge are likely to contribute to a more sophisticated risk analysis. We position participation and transdisciplinarity as effective approaches for collecting important and complex qualitative data to explain quantitative biological data (exposure, dose-response). They could contribute in bringing together different data collection techniques (e.g. questionnaire survey, Participatory Rural Appraisal (PRA) and focus group discussion) to reduce the cost of risk analysis and also to provide broader evidence for decision making in the animal source food informal sector

Bacterial risk assessment in informally produced milk consumption in Côte d’Ivoire

BACKGROUND: Fifteen dairy farms from five zones of Abidjan, Côte d’Ivoire, were characterized to assess the conditions of raw milk production and marketing, and detect whether Bacillus cereus presented a risk to the consumer. METHODS: In total, 119 udder milk, 113 udder skin swabs, 22 hand swabs of farmers, 14 mixture milk of shepherd, 14 utensils rinse water, 16 environment samples and water used to rinse material for milking in 5 farms were sampled. Three informal markets in these zones were visited and 17 retailer pooled milk samples were collected and analyzed. The isolated strains were characterized and their virulence genes were detected by polymerase chain reaction (PCR). Milk quality was determined by comparing the average count of B. cereus to the limits of acceptability. To assess the impact of the consumption of raw milk, a consumer survey was conducted on 188 clients selected randomly at informal markets. RESULTS: 26.6% (32/119) of raw milk samples taken directly from the cow’s udders, 28.6% (4/14) mixture milk of shepherd and 41.2% (7/17) of retailer pooled milk were contaminated by B. cereus. Regarding limits of acceptability, 28.6% (2/7) of retailer pooled milk samples met the standards, 28.6% (2/7) presented a potential risk of disease and 42.8% (3/7) posed a real risk of foodborne poisoning. The sources of contamination of milk by B. cereus were, by decreasing order of importance, the udder (73/113), the water (3/5), the environment (9/16), the milk vendor containers (7/17), the hands of the milker(s) (9/22) and the utensils (4/14). All B.cereus strains (88 strains) isolated were virulent and harbored at least one of the virulence genes hblA, hblC, hblD, nheA, nheB, nheC, bceT and cytK-2. The most frequent virulence genes were hblD (79/88), cytK-2 (79/88), nheC (65/88) and hblC (60/88), all involved in the aetiology of diarrheal syndromes. Among milk consumer’s respondents, 12.8% (24/188) reported episodes of symptoms including diarrhea (19/37), fever (5/37), bloating stomach (4/37), vomiting (3/37) and nausea (1/37). Severe cases requiring a stay of one to three days in hospital were reported by 12.5% (3/24) of those infected. SUMMARY: The probability of consuming milk contaminated by B. cereus was 22.2%. The occurrence of foodborne diseases was significantly related (p < 0.05) to the consumption of unpasteurized milk (Relative Risk (RR): 2.6, 95% CI 1.07 - 6.22). Milk quality could be improved by the introduction of good hygiene practices such as water quality, utensil washing and milk pasteurization. Awareness of stakeholders in the informal dairy sector is also crucial to reduce the risk of infection for the consumer

Contamination of raw milk with Bacillus cereus from farm to retail in Abidjan, Côte d'Ivoire and possible health implications

In Africa, milk and dairy products play an important role in human nutrition but could represent a risk to human health, due to poor hygiene throughout the production chain. This study aimed firstly to assess the contamination of raw milk produced in traditional dairy farms in Abidjan with Bacillus cereus from farm to retail and secondly to assess the associated health risk for consumers in informal markets using a participatory approach. In total, 320 samples including 150 milk samples were collected in 15 purposively selected traditional dairy farms from four sites of Abidjan and analysed according to EN ISO 7932:2004 with slight modification. In addition, a survey was conducted in the three informal markets with 188 individuals who bought milk. B. cereus was found in 27% of the udder milk samples while 41% of the samples taken from seller’s pooled milk contained B. cereus. Out of the 183 milk consumers, 14% reported daily consumption of unheated milk, indicating the high probability of exposure to B. cereus and other foodborne illnesses. After milk consumption, 13% of consumers reported that they contracted a foodborne illness. In conclusion, milk produced and sold in informal markets in Abidjan represents a risk for consumers’ health and B. cereus is one possible cause. Milk quality could be improved by good hygiene practices, strengthening and targeting educational interventions and effective monitoring throughout the production and delivery chain

Hazard identification and exposure assessment for bacterial risk assessment of informally marketed milk in Abidjan, Côte d'Ivoire

Background. Animal-source foods are important causes of food-borne illness, and milk and dairy products can contain pathogenic microorganisms. Objective. We conducted a stochastic assessment of the risk of ingesting milk contaminated with specific microbial pathogens (Escherichia coli, Staphylococcus aureus, and Enterococcus spp.) in Abidjan, Côte d'Ivoire. Methods. We carried out structured interviews and focus group discussions with farmers (n = 15), vendors (n = 17), and consumers (n = 188) to characterize dairy production systems and milk consumption behavior. Microbiological sampling was conducted at different points between milking and sale. A risk model was developed, and the risk of consuming contaminated raw milk was estimated by Monte Carlo simulation. Results. The investigation into local raw milk consumption patterns showed that the proportion of raw milk consumption was 51.6% in people who consume milk. The probability of ingestion of marketed raw milk that failed to meet standards for this group of bacteria was 29.9% and about 652 consumers per day were estimated to ingest contaminated milk. Microbiological tests from the farm showed that 7.2% of samples taken from milkers' hands, 4.4% of water samples (water used to rinse milk containers or milking utensils (calabash, plastic bottle, filters, buckets), 4.4% of environmental samples (air pollution), 13.2% of samples from milking utensils, and 4.9% of samples from cows' udders were contaminated with one or more of these pathogens. About 624.6 L of marketed raw milk would need to be discarded per day if discarding milk was chosen as the option of risk reduction. The destruction of this milk would result in a potential loss of €623.9 per day for all producers. Conclusions. The risk of human illness from consumption of raw milk could be mitigated by raising awareness about heat treatment of milk and good hygiene practices in the dairy chain