Andrea Gori* , Alessandra Bandera*, Giulia Marchetti*, Anna Degli Esposti*, Lidia Catozzi*, Gian Piero Nardi*, Lidia Gazzola*, Giulio Ferrario*, Jan D.A. van Embden†, Dick van Soolingen†, Mauro Moroni*, and Fabio Franzetti*
Author affiliations: *University of Milan, Milan, Italy; †National Institute of Public Health and Environmental Protection, Bilthoven, the Netherlands
The opinions expressed by authors contributing to this journal do not necessarily reflect the opinions of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above.