Absence of Escherichia coli O157:H7 in waters

Escherichia coli O157:H7 produces a toxin called Shiga-like toxin, which has been associated with haemolytic uremic syndrome (HUS), haemorrhagic colitis and thrombocytopaenic purpura. Infections in humans are associated with consumption of contaminated food such as meat and raw milk. Early in the year 1996, several cases of HUS in children were reported in Argentina. In most cases, the infection source could not be determined. Consequently, several health centres began to distrust water as a transmission media. A total of 493 water samples from different regions, industries and institutions in Santa Fe Province were analysed. None of the analysed samples showed the presence of E. coli O157:H7 and the mechanism of its transmission through water remains unknown.