Next Article in Journal
Exposure Modelling of Extremely Low-Frequency Magnetic Fields from Overhead Power Lines and Its Validation by Measurements
Previous Article in Journal
Perceived Injury Risk among Junior Cricketers: A Cross Sectional Survey
Article Menu
Issue 8 (August) cover image

Export Article

Open AccessArticle
Int. J. Environ. Res. Public Health 2017, 14(8), 947; doi:10.3390/ijerph14080947

Surface Sampling Collection and Culture Methods for Escherichia coli in Household Environments with High Fecal Contamination

1
Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205-2179, USA
2
Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205-2179, USA
3
Asociación Benéfica Proyectos de Informática, Salud, Medicina, y Agricultura (A.B. PRISMA), Iquitos, Peru
*
Author to whom correspondence should be addressed.
Academic Editor: Helena Solo-Gabriele
Received: 20 July 2017 / Revised: 14 August 2017 / Accepted: 18 August 2017 / Published: 22 August 2017
(This article belongs to the Section Environmental Science and Engineering)
View Full-Text   |   Download PDF [315 KB, uploaded 22 August 2017]

Abstract

Empiric quantification of environmental fecal contamination is an important step toward understanding the impact that water, sanitation, and hygiene interventions have on reducing enteric infections. There is a need to standardize the methods used for surface sampling in field studies that examine fecal contamination in low-income settings. The dry cloth method presented in this manuscript improves upon the more commonly used swabbing technique that has been shown in the literature to have a low sampling efficiency. The recovery efficiency of a dry electrostatic cloth sampling method was evaluated using Escherichia coli and then applied to household surfaces in Iquitos, Peru, where there is high fecal contamination and enteric infection. Side-by-side measurements were taken from various floor locations within a household at the same time over a three-month period to compare for consistency of quantification of E. coli bacteria. The dry cloth sampling method in the laboratory setting showed 105% (95% Confidence Interval: 98%, 113%) E. coli recovery efficiency off of the cloths. The field application demonstrated strong agreement of side-by-side results (Pearson correlation coefficient for dirt surfaces was 0.83 (p < 0.0001) and 0.91 (p < 0.0001) for cement surfaces) and moderate agreement for results between entrance and kitchen samples (Pearson (0.53, p < 0.0001) and weighted Kappa statistic (0.54, p < 0.0001)). Our findings suggest that this method can be utilized in households with high bacterial loads using either continuous (quantitative) or categorical (semi-quantitative) data. The standardization of this low-cost, dry electrostatic cloth sampling method can be used to measure differences between households in intervention and non-intervention arms of randomized trials. View Full-Text
Keywords: fomites; surfaces; sanitation; fecal contamination; environmental sampling; Escherichia coli; infections/transmission; methods/microbiology fomites; surfaces; sanitation; fecal contamination; environmental sampling; Escherichia coli; infections/transmission; methods/microbiology
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

Share & Cite This Article

MDPI and ACS Style

Exum, N.G.; Kosek, M.N.; Davis, M.F.; Schwab, K.J. Surface Sampling Collection and Culture Methods for Escherichia coli in Household Environments with High Fecal Contamination. Int. J. Environ. Res. Public Health 2017, 14, 947.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Int. J. Environ. Res. Public Health EISSN 1660-4601 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top