Authors: TEREI Nadine, Ban-bo Bebanto Antipas, Gandolo Bongo Nare Richard, Bidjeh Kebkiba.
Objective: Irrigation of market garden crops in the city of N'Djaména is done through wastewater often heavily soiled by human and animal faeces. The aim of this study was to identify salmonella in market garden products and irrigation sources in the city of N'Djaména.
Methodology and Results: Samples of water and lettuce (Lactuca sativa L.) were taken from market gardens in 16 sites covering 7 districts (1, 3, 5, 7, 8, 9 and 10) of the city of N'Djaména. Microbiological analysis was done according to ISO 6579:2002. Salmonella strains were isolated according to the standard microbiology method and confirmed by the Api 20 E bacterium. Market gardening is practiced by 87.87% of men and 12.12% of women, most of whom are illiterate (53.03%). However, 84.84% of producers have no knowledge of biosafety; 80.30% do not know what salmonellosis is; 78.78 recognize that the use of wastewater in market gardening constitutes a danger to the health of producers and consumers. The rate of contamination of water by salmonella by district was: 94.44% in the 1st ; 91.66% in the 9th; 81.57% in the 7th; 80% in the 10th; 78.26% in the 3rd; 69.69% in the 5th and 68.96% in the 8th. According to the seasons: the prevalence was 85% in the dry season, 76% in the rainy season. The prevalence of salmonella in the different types of irrigation water was: 88.48%; 86.40%; 83.33% and 35.71% in pond water, wastewater, river water and borehole water respectively. The contamination rate in lettuce was: 93.10% in the 9th; 92.10% in the 1st; 92.% in the 7th; 91.66% in the 3rd; 90.90% in the 10th; 88.88% in the 5th, and 86.95% in the 8th. According to the seasons, salmonella contamination was 92.59% in the dry season and 89% in the rainy season. For fertilizers, the prevalence was 88% for simple dung, while for dung associated with synthetic fertilizer, it was 86%.
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