Comparison of two methods for evaluating the quality of stored drinking water in Abidjan, Côte d'Ivoire, and review of other comparisons in the literature

Membrane filtration, multiple tube fermentation (the standard methods) and Colilert are techniques available for assessing drinking water quality, but there are no published comparisons of Colilert to standard methods in a developing country laboratory. We reviewed the published literature on Colilert and standard methods and conducted a study to compare Colilert with membrane filtration for the detection and enumeration of total coliforms and fecal coliforms (Escherichia coli bacteria) using 35 stored drinking water samples from households in Abidjan, Côte d'Ivoire. Our study results are consistent with previous published studies conducted in developed countries. Results from Colilert and membrane filtration correlated for both total coliforms (r2=0.81) and E. coli (r2=0.93). Colilert is an acceptable method to measure the presence and quantity of coliforms in water samples in a developing country setting.