Ruminants Contribute Fecal Contamination to the Urban Household Environment in Dhaka, Bangladesh

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• 作者：Angela R. Harris ; Amy J. Pickering ; Michael Harris ; Solaiman Doza ; M. Sirajul Islam ; Leanne Unicomb ; Stephen Luby ; Jennifer Davis ; Alexandria B. Boehm
• 刊名：Environmental Science & Technology
• 出版年：2016
• 出版时间：May 3, 2016
• 年：2016
• 卷：50
• 期：9
• 页码：4642-4649
• 全文大小：364K
• 年卷期：0
• ISSN：1520-5851

文摘

In Dhaka, Bangladesh, the sensitivity and specificity of three human, three ruminant, and one avian source-associated QPCR microbial source tracking assays were evaluated using fecal samples collected on site. Ruminant-associated assays performed well, whereas the avian and human assays exhibited unacceptable cross-reactions with feces from other hosts. Subsequently, child hand rinses (n = 44) and floor sponge samples (n = 44) from low-income-households in Dhaka were assayed for fecal indicator bacteria (enterococci, Bacteroidales, and Escherichia coli) and a ruminant-associated bacterial target (BacR). Mean enterococci concentrations were of 100 most probable number (MPN)/2 hands and 1000 MPN/225 cm² floor. Mean concentrations of Bacteroidales were 10⁶ copies/2 hands and 10⁵ copies/225 cm² floor. E. coli were detected in a quarter of hand rinse and floor samples. BacR was detected in 18% of hand rinse and 27% of floor samples. Results suggest that effective household fecal management should account not only for human sources of contamination but also for animal sources. The poor performance of the human-associated assays in the study area calls into the question the feasibility of developing a human-associated marker in urban slum environments, where domestic animals are exposed to human feces that have been disposed in pits and open drains.