1 Department of Health Sciences, University of Genoa, Genoa, Italy; Hygiene Unit, IRCCS Policlinico San Martino Hospital, 16132 Genoa, Italy. Electronic address: sticchi@unige.it.
2 Department of Medical Sciences, University of Ferrara, Ferrara, Italy.
3 Infectious Diseases Unit, Scientific Institute for Research, Hospitalization, and Health Care, IRCCS Istituto Giannina Gaslini, Genoa, Italy.