1. Department of Maternal Infantile and Urological Sciences Sapienza University of Rome Rome Italy
2. Department of History, Society and Human Studies Statistics for Experimental and Technological Research University of Salento Lecce Italy
3. Laboratory of Virology, Department of Molecular Medicine Sapienza University of Rome Rome Italy
4. Department of Epidemiology Lazio Regional Health Service Rome Italy
5. Unit of Epidemiology Anna Meyer Children's University Hospital Florence Italy