CMV lesions were found in the olfactory system of children with congenital CMV infection but no study has hitherto examined the impact of congenital CMV infection on olfaction. So the investigators propose in this study to assess the proportion of children with olfactory deficits among children with congenital CMV infection. Second this study will also evaluate performances of a new olfactory test, based on discrimination of binary odorant mixtures.