 The search for viral factors responsible for the increased T1D prevalence in youth children is difficult to implement. The absence or scarcity of infections is difficult to assess robustly at the individual level. The analysis of digestive, ENT or blood samples in the search for viruses themselves can only be done at T1D diagnosis and is therefore unlikely to be positive several years after the causal infection. It is not possible to reconstitute retrospectively viral events, which an individual has been exposed between birth and date of diabetes diagnosis. That is why our project proposes to use a proxy of viral infections crossed by a child, quantifying viral exposures to which he was submitted before the T1D diagnosis. We focused on early childhoods viral infections that may interfere with early forms of T1D. We combine 2 data sources: 