1 Center for HUS Prevention Control and Management at the Pediatric Nephrology Dialysis and Transplant Unit Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico, Milano, Italy.
2 Center for HUS Prevention Control and Management at the Laboratory of Microbiology, Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico, Milano, Italy.
3 Epidemiology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milano, Italy.