Patienthèque of Finisterian (South of Brittany) Children With Cystic Fibrosis in the Time of Precision Medicine

Inclusion Criteria: * Newly screened infants with a confirmed diagnosis of cystic fibrosis in its classic form (clinical symptoms and two positive sweat tests and/or two mutations of the cftr gene from Class I to III) * Children free of any colonization with P. aeruginosa * Affiliation with the social security system * Consent signed by the holders of parental authority or the sole parent holding parental authority Exclusion Criteria: * Children colonized with P. aeruginosa according to the cytobacteriological examination and / or molecular test of sputum or pharyngeal specimens * Children grafted * Children not affiliated to a social security scheme or not entitled to * Children whose parent (s) are (are) minor (s) * Children whose holders of parental authority do not master the French language * Refusal to participate in the study