Overview of Major Bacterial Contaminants of Drinking Water in Nigeria: A Review

Abstract

Aim and Objectives: The objective of this study was to provide an overview of the microorganisms implicated in the contamination of household drinking water in Nigeria, their pattern of distribution and the regulatory gap(s) if any that is responsible for the cases of drinking water contamination and water borne diseases in Nigeria. Study Design and Methodology: The methodology employed for this study involved a comprehensive and critical review of ten randomly selected studies to identify the major bacterial contaminants of drinking water in Nigeria and their distribution. This review was restricted to microbiological measures of drinking water contamination excluding chemical aspects of water quality. Results: Escherchia coli was found to be the predominant microbial contaminant of drinking water in the studies reviewed with 70%, Klebsiella sp 60%, Pseudomonas aeruginos 60%, Staphylococcus aureus 50%, Proteus sp 50%, Enterobacter aerogenes 40%, Streptococcus fecalis 30%, Salmonella typhi 30% and 10% for Vibrio cholerae and Shigella sp. Conclusion: The presence of microbes in drinking water especially E. coli reported in 70 percent of the studies reviewed is a source of concern. The presence of toxin producing strains of E. coli like the O157:H7 in drinking water can result in fatal consequences like hemorrhagic diarrhea and kidney failure. The widespread presence of other disease-causing organisms further confirms that a good number of the drinking water presented as safe for consumption across Nigeria are actually not fit for human consumption. The gaps reported in most of the studies reviewed were mainly oversight gaps in monitoring by the National Agency for Food and Drug Administration and control, NAFDAC, the agency charged with monitoring food and drugs in the country.