Detection of coliforms in drinking water and its effect on human health - a review

The coliform group has been used extensively as an indicator of water quality and has historically led to the public health protection concept. Total coliforms are a group of bacteria commonly found in the environment, for example in soil or vegetation, as well as the intestines of mammals, including humans. Total coliform bacteria are not likely to cause illness, but their presence indicates that the water supply may be vulnerable to contamination by more harmful microorganisms. Escherichia coli (E. coli) is the only member of the total coliform group of bacteria that is found only in the intestines of mammals, including humans. The presence of E. coli in water indicates recent fecal contamination and may indicate the possible presence of disease-causing pathogens, such as bacteria, viruses, and parasites. Although most strains of E. coli bacteria are harmless, certain strains, such as E.coli 0157:H7, may cause illness. About 80 % of communicable diseases in the world are waterborne. According to WHO estimate about 80 % of water pollution in developing country, like India is carried by domestic waste. In India 70 % of the water is seriously polluted and 75 % of illness and 80 % of the child mortality is attributed to water pollution. The improper management of water systems may cause serious problems in availability and quality of water. The major pathogenic bacteria responsible for water borne disease are spread by the faeco-oral route, in which water may play an intermediate role. The aim of this review is to examine methods currently in use for the detection of coliforms in drinking water and also to evaluate the possible health hazards associated with drinking water contaminated with coliforms.