Fecal Contamination on Produce from Wholesale and Retail Food Markets in Dhaka, Bangladesh

• Published in: The American journal of tropical medicine and hygiene Vol. 98; no. 1; pp. 287 - 294
• Main Authors: Harris, Angela R, Islam, Mohammad Aminul, Unicomb, Leanne, Boehm, Alexandria B, Luby, Stephen, Davis, Jennifer, Pickering, Amy J
• Format: Journal Article
• Language: English
• Published: United States Institute of Tropical Medicine 01.01.2018; The American Society of Tropical Medicine and Hygiene
• Subjects: Bangladesh; E coli; Escherichia coli; Feces; Feces - microbiology; Food Contamination - statistics & numerical data; Food Microbiology; Food Safety; Food Supply - statistics & numerical data; Humans; Meat industry; Risk Factors; Vegetables - microbiology; Bangladesh
• ISSN: 0002-9637; 1476-1645
• DOI: 10.4269/ajtmh.17-0255

Fresh produce items can become contaminated with enteric pathogens along the supply chain at the preharvest (e.g., irrigation water, soil, fertilizer) or postharvest (e.g., vendor handling or consumer handling) stages. This study assesses the concentrations of fecal indicator bacteria , enterococci (ENT), and Bacteriodales on surfaces of carrots, eggplants, red amaranth leaves, and tomatoes obtained from both a wholesale market (recently harvested) and neighborhood retail markets in Dhaka, Bangladesh. We detected in 100% of carrot and red amaranth rinses, 92% of eggplant rinses, and 46% of tomato rinses. Using a molecular microbial source tracking assay, we found that 32% of produce samples were positive for ruminant fecal contamination. Fecal indicator bacteria were more likely to be detected on produce collected in retail markets compared with that in the wholesale market; retail market produce were 1.25 times more likely to have detected ( = 0.03) and 1.24 times more likely to have ENT detected ( = 0.03) as compared with wholesale market produce. Bacteriodales was detected in higher concentrations in retail market produce samples compared with wholesale market produce samples (0.40 log gene copies per 100 cm higher, = 0.03). Our results suggest that ruminant and general fecal contamination of produce in markets in Dhaka is common, and suggest that unsanitary conditions in markets are an important source of produce fecal contamination postharvest.