Large-scale trials of drinking water quality in Ghana and the Philippines comparing the WatMap Portable Water Quality Kit with Colilert Quanti-Tray

Millions of people worldwide don't understand the connection between contaminated drinking water and waterborne diseases. And, cumbersome, expensive microbial indicator standard test methods make water quality field tests difficult.

We report on the first large-scale trials comparing the EC-Kit Portable Microbiology Lab with Colilert Quanti-Tray®, a method approved in the U.S. and 35 countries worldwide. The EC-Kit Portable Microbiology Lab is a simple, state-of-the-art kit that contains two complementary tests for Escherichia coli, the Colilert 10 ml presence/absence test and 3M™'s Petrifilm™ test, also a waist-belt incubator, ultraviolet light, turbidity tube and more.

Over 6,000 tests of source and household water quality were conducted over 12 months in Northern Region, Ghana and Capiz Province, Philippines and various other countries. E. coli counts from the EC-Kit tests correlated well with the Quanti-Tray® results. Drinking water from surface water sources and open, unprotected wells were found to pose a high risk of disease. Water from boreholes and protected supplies posed a lower risk at the source, but with deterioration at the household level.

Results verify the advantages of the EC-Kit: simplicity, sophisticated microbiology for US$3 per set, test results in 12-24 hours correlating with WHO disease risk categories, and the ability for tests to be performed anywhere – off the electrical grid, without clean lab conditions. Public health policy and practice implications for international water quality testing are significant. With simple instructions, communities can test their drinking water. The EC-Kit tests can provide immediate feedback on public health interventions. Recommendations include a call for wide-scale deployment.