Surveillance of Rotavirus Gastroenteritis

* Epidemiological studies have shown the diversity of resistance genotypes and the evolution of their prevalence in the paediatric population. This large study conducted in a context of very low vaccination coverage will generate more precise data on the natural epidemiological evolution of rotavirus, notably the G9 genotype, which has appeared relatively recently. * This study will allow us to identify and document rare or unusual strains of human or animal origin. The complete genetic characterization of these strains will also make it possible to study their ability to recombine and to assess the risk of emergence. Among these still rare strains, the investigators are particularly monitoring G12 rotavirus, whose ability to recombine raises the risk of emergence. * For at least one of the centres taking part in the study, the paediatric population studied will be given strong vaccination coverage. It will be extremely interesting to compare the results obtained in the vaccinated population with non-vaccinated children to assess the impact of this vaccination on the distribution of rotavirus genotypes