Gastroenteritis - epidemiology, France - epidemiology, Virus Diseases - epidemiology, Enterovirus - classification, Norwalk virus - classification, Humans, Disinfection, Gastroenteritis - virology, Shellfish - virology, Hepatovirus - classification, Sewage - virology, Food Microbiology, Mamastrovirus - classification, Rain, Disease Outbreaks, Rotavirus - cla...