Bacterial indicators of faecal pollution of water supplies and public health: a review

Bacterial indicators of faecal pollution of water supplies and their significance to public health are reviewed in this paper, to highlight their levels of general acceptability and suitability as safeguards against health hazards associated with water supplies. Regular bacteriological analysis with the sole aim of detecting faecal coliform as a confirmation of faecal pollution, is shown to constitute a safeguard against health hazards arising from the consumption of faecally-polluted water. It is also shown that available indicators cannot be fully relied upon for total safeguard espericially as Cryptosporidium oocysts and Giardia cysts have been implicated in some water-borne outbreaks of gastroenteritis. Furthermore, there are still problems of confusing ecology, characterization and taxonomy, growth temperature in both temperate and hot climates, coupled with the fact that several non-classical indicators, e.g., Bifidobacterium, Bacteroides, Eubacterium, etc., have been found to be equally attractive as apparently reliable indicators. This confusing situation appears to have created considerable doubt on the general acceptability of classical indicators (e.g. coliforms, Streptococcus faecalis and Clostridum perfringens), as safeguards against water-related infection. In perspective, further research on methods of detecting reliable indicators in addition to maintaining hygienic principles in homes, are recommended. KEY WORDS: Water Pollution, Bacterial indicators, General acceptability, Public Health. Global Jnl Medical Sciences Vol.2(2) 2003: 81-9