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Laboratory and Field Performance Evaluations of a Novel Escherichia coli Field TestEPA Grant Number: FP917512
Title: Laboratory and Field Performance Evaluations of a Novel Escherichia coli Field Test
Investigators: Wang, Alice
Institution: University of North Carolina at Chapel Hill
EPA Project Officer: Zambrana, Jose
Project Period: August 16, 2012 through August 15, 2015
Project Amount: $126,000
RFA: STAR Graduate Fellowships (2012) RFA Text | Recipients Lists
Research Category: Academic Fellowships , Fellowship - Environmental Microbiology
The four EPA-approved methods for detecting Escherichia coli in water sources are expensive (i.e., more than $3/sample) and require extensive laboratory training along with non-portable or fragile equipment. Thus water-quality managers, public health and sanitation officials, and individuals living in low-resource settings often make decisions that affect the health of the public without reliable water-quality information that is not necessarily indicative of true health risks. Microbial water-quality testing in low-resource settings is one of the greatest challenges in implementing safe water programs in developing nations. The CBT is a novel water-quality field test that overcomes the current water-quality testing obstacles in low-resource settings. Additional laboratory experiments are needed to further characterize the performance of the test to detect E. coli bacteria in water, as well as to produce a version of the test that can be pilot tested in the field.
The water used with the CBT will be speciated to confirm that the CBT accurately is detecting E. coli with biochemical tests, as well as molecular methods such as polymerase chain reaction (PCR). Performance validations of the CBT also will include the incorporation of the CBT within U.S. Agency for International Development (USAID)-supported Demographic Health Surveys (DHS), previously in a Peruvian DHS in 2011, and in the planning process for a Liberian DHS in 2013. User feasibility and implication of knowledge of microbial water quality also will be assessed via semi-quantitative surveys in collaboration with United Nations (UN)-Habitat in Mwanza, Tanzania, in the summer of 2012.
Preliminary laboratory experiments demonstrate that via biochemical assays, the positive chambers in a CBT are truly E. coli. Future laboratory experiments speciating positive waters via molecular methods such as PCR and electrophoresis also likely will be true positives for E. coli.
Potential to Further Environmental/Human Health Protection
Improving the CBT for preparation to be a commercially viable product has significant implications. The CBT meets the criteria of being inexpensive, simple, robust and portable, such that the test can be used in even rural and rugged areas of a developing country. The simplicity of the test allows anyone with brief training to test their own water, thereby empowering people with knowing if their water is safe so that they can determine their own remedial actions. There are several applications of this technology, including water-quality management of water quality, food safety and disaster preparedness. Evaluation of the CBT in the field and documentation of observations will illuminate significantly the challenges of testing and possible solutions to problems facing the CBT test. Furthermore, the water-quality results from the inclusion of CBT in household surveys can depict better where we stand in our Millennium Development Goals on drinking water and provide quality actionable data for local interventions and national policy change.