Outbreak of waterborne acute gastroenteritis (AGE) in Pleaux, Cantal, April 2012.

On April 12, 2012, the ARS notified the Auvergne Regional Health Agency (Cire Auvergne) of a high level of microbiological contamination in the water supply system of the municipalities of Pleaux and Barriac-les-Bosquets, in the Cantal department.The cohort study conducted estimated the overall health impact of this outbreak at 477 cases of AGE among the 1,786 people served by the water system. A strong association between the occurrence of acute gastroenteritis (AGE) and the consumption of tap water (RR = 1.69; 95% CI [1.27–2.27]) was identified, with notable differences depending on the presence of re-chlorination systems in the network. Operational and monitoring failures at the water treatment plant and in the distribution network were identified. Analysis of health insurance reimbursement data for the 2009–2011 period confirms the vulnerability of this water network by identifying at least two other AGE outbreaks in this area, the waterborne origin of which is highly probable.