Nosocomial infections constitute a serious problem for public health. They develop by various ways, and their detection, at early stages, is not always easy. Furthermore, their follow-up requires the collaboration of several partners, which is very complex and sometimes inefficient. The objective is to produce collaborative platform of diagnosis and follow-up of the disease in order to bring a real-time analyse of the situation and an automatic transfer of the adequate data to various institutional and medical partners. Each partner can access the system with interfaces that are adapted to the user's profile (doctors, nurse, technician, etc.). These interfaces takes in consideration the heterogeneous of platforms to access the system (mobile phone, PDA, computer). Our proposal will be set up and validated at the Civil Hospices of Lyon, aiming to accelerate the detection and the follow-up of Legionella in Edouard Herriot hospital's units. If the system is conclusive, it will be applied in other hospitals.