1. Department of Infectious Tropical Diseases and Microbiology , IRCCS Sacro Cuore Don Calabria Hospital, 37024 Negrar di Valpolicella, Verona , Italy
2. Department of Global Health , Boston University School of Public Health, Boston, MA 02118 , USA
3. Section of Infectious Diseases , Boston University School of Medicine, Boston, MA 02118 , USA
4. National Emerging Infectious Diseases Laboratories , Boston University, Boston, MA 02118 , USA
5. Center for Emerging Infectious Disease Research and Policy , Boston University, Boston, MA 02118 , USA