Research Article: Prevalence and Association of Escherichia coli and Diarrheagenic Escherichia coli in Stored Foods for Young Children and Flies Caught in the Same Households in Rural Bangladesh

Date Published: April 12, 2018

Publisher: The American Society of Tropical Medicine and Hygiene

Author(s): Solaiman Doza, Musarrat Jabeen Rahman, Mohammad Aminul Islam, Laura H. Kwong, Leanne Unicomb, Ayse Ercumen, Amy J. Pickering, Sarker Masud Parvez, Abu Mohd Naser, Sania Ashraf, Kishor Kumar Das, Stephen P. Luby.


Consumption of contaminated stored food can cause childhood diarrhea. Flies carry enteropathogens, although their contribution to food contamination remains unclear. We investigated the role of flies in contaminating stored food by collecting food and flies from the same households in rural Bangladesh. We selected 182 households with children ≤ 24 months old that had stored foods for later feeding at room temperature for ≥ 3 hours. We collected food samples and captured flies with fly tapes hung by the kitchen. We used the IDEXX Quanti-Tray System (Colilert-18 media; IDEXX Laboratories, Inc., Westbrook, ME) to enumerate Escherichia coli with the most probable number (MPN) method. Escherichia coli–positive IDEXX wells were analyzed by polymerase chain reaction for pathogenic E. coli genes (eae, ial, bfp, ipaH, st, lt, aat, aaiC, stx1, and stx2). Escherichia coli was detected in 61% (111/182) of food samples, with a mean of 1.1 log10 MPN/dry g. Fifteen samples (8%) contained pathogenic E. coli; seven (4%) had enteropathogenic E. coli (EPEC) genes (eae and/or bfp); and 10 (5%) had enteroaggregative E. coli genes (aat and/or aaiC). Of flies captured in 68 (37%) households, E. coli was detected in 41 (60%, mean 2.9 log10 MPN/fly), and one fly (1%) had an EPEC gene (eae). For paired fly-food samples, each log10 MPN E. coli increase in flies was associated with a 0.31 log10 MPN E. coli increase in stored food (95% confidence interval: 0.07, 0.55). In rural Bangladesh, flies possibly a likely route for fecal contamination of stored food. Controlling fly populations may reduce contamination of food stored for young children.

Partial Text

To ensure adequate nutritional intake, liquid or semisolid foods are recommended for children after the age of 6 months to complement breastfeeding.1,2 In the context of Bangladesh, such foods can be dedicated foods prepared for the children, or it can be any regular food that is cooked for the family for the day.3–5 Young children’s foods commonly comprise suji, a traditional recipe containing rice/wheat powder, milk, sugar/molasses, and khichuri, a preparation of rice with lentils and vegetables, and also regular rice.3 The introduction of liquid or semisolid foods can also increase the risk of enteric pathogen transmission to children if these foods are contaminated.4–7 In rural Bangladesh, foods stored for multiple feeding events over the course of several hours were found to have a high microbial count and were associated with diarrhea among children < 24 months old.4 Stored foods in rural Bangladeshi households were contaminated with diarrheagenic E. coli that could be consumed by children ≤ 24 months old. Both fly density and fly contamination levels were associated with food contamination levels, suggesting that flies may have a potential role in fecal contamination of foods stored for feeding of young infants. Particularly, houseflies were dominantly captured and frequently had a high E. coli count. Because houseflies are known to breed on open manure and feed on foods they get access to, they can be the potential link between fecal bacteria and contaminated foods.21,22,39   Source:


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