Giuliano Rizzardini1, Umberto Restelli, Davide Croce. 1. aDepartment of Infectious Diseases, L. Sacco University Hospital, Milan bCREMS (Centre for Research on Health Economics, Social and Healthcare Management), University Carlo Cattaneo - LIUC, Castellanza, Varese, Italy cSchool of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.