Bacterial gastroenteritis can cause serious long-term health problems such as hypertension and kidney failure, Canadian researchers warn.
This statement emerges from results of an examination of the extended health effects due to an outbreak of acute gastroenteritis in the small rural town of Walkerton in Ontario, Canada, when drinking water was contaminated with Escherichia coli 0157:H7 and Campylobacter bacteria.
Heavy rainfall contributed to the surface transport of fecal contaminants from livestock into inadequately chlorinated drinking water supplied from a shallow well.
Over 2300 people became ill with acute gastroenteritis, including 27 who developed hemolytic uremic syndrome. There were also six deaths, the authors write in the Canadian Medical Association Journal.
Among the 1958 adults with no known history of hypertension or kidney disease who participated in the follow-up study, 675 were asymptomatic during the outbreak, 909 had moderate symptoms of acute self-limited gastroenteritis, and 374 had severe symptoms needing medical attention.
An average of 3.7 years after the outbreak, 27% of the asymptomatic participants were diagnosed with hypertension, compared with 32% and 36% of those with moderate and severe symptoms of gastroenteritis, respectively.
The adjusted relative risk of hypertension was significantly increased for those with severe symptoms compared with those who remained asymptomatic at the time of the outbreak, at 1.28, although for moderate symptoms, this result did not reach statistical significance, the scientists, led by Amit Garg from the London Health Sciences Center in Ontario, say.
A similar graded association was seen for reduced kidney function, defined as an estimated glomerular filtration rate of below 60 ml/min per 1.73 m2, although gastroenteritis was not linked with albuminuria, they add.
"In conclusion, acute self-limited bacterial gastroenteritis necessitating medical attention may be an independent risk factor for long-term hypertension and reduced kidney function," the authors comment.
"Maintaining safe drinking water remains essential to human health, as transient bacterial contaminations may have implications well beyond a period of acute self-limited illness."
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