1. Department of Health Promotion, Mother and Child Care, Internal Medicine and Medical Specialties ‘G. D’Alessandro’, University of Palermo, Italy
2. Clinical Epidemiology Unit and Regional Reference Laboratory of Western Sicily for the Emergence of COVID-19, University Hospital ‘P. Giaccone’, Palermo, Italy
3. General Directorate of Health Prevention, Ministry of Health, Rome, Italy
4. National Institute of Health (Istituto Superiore di Sanità), Rome, Italy
5. Regional Health Authority of Sicily, Palermo, Italy
6. Department of Laboratory Diagnostics, Local Health Unit of Palermo, Palermo, Italy
7. University of Udine, Udine, Italy
8. Health and Migration Programme (PHM), World Health Organization, Geneva, Switzerland
9. Vita – Salute San Raffaele University, Milan, Italy
10. Division of Biostatistics & Epidemiology Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, USA