1. Unit of Paediatric Surgery, Woman-Mother-Child Department, Lausanne University Hospital (CHUV), Lausanne, Switzerland
2. Unit of Paediatric and Infectious Diseases and Vaccinology, Woman-Mother-Child Department, Lausanne University Hospital (CHUV), Lausanne, Switzerland
3. Institute of Microbiology, Department of Laboratory, University of Lausanne and Lausanne University Hospital (CHUV), Lausanne, Switzerland