- Correspondence to Matteo Vitali, Dipartimento di Sanità Pubblica e Malattie Infettive, Sapienza Università di Roma, Piazzale Aldo Moro, 5-00185 Roma, Italy;
- Received July 29, 2010
- Accepted June 13, 2011
- First published July 5, 2011.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.