The re-elaboration of John Snow’s map in a GIS environment. Input for transferring methodological and applied skills being inspired by a virtuous practical example of social utility

John Snow’s map made it possible to save many human lives by interrupting the spread of cholera, in an area of London in 1854 after the study of a relevant number of cases which allowed him to put his assumptions and research into practice. His work had a crucial role for future developments of epidemiology and provided the basis for (geo)spatial discussions and density studies in relation to risk factors and his insights enabled cartographic and successively GIS approaches, as support to medical studies, to have remarkable advances. In this contribution – conceived on the basis of a practical initiative held for the GIS Day 2019 Medical geography and GIS applications for social utility (Rome, 11 November 2019) – we propose a re-elaboration of John Snow’s map in a GIS environment, underlining how demonstrative-laboratory activities focused on specific cases can provide remarkable inputs for transferring methodological and applied skills, being inspired by a virtuous example of social utility. In particular, we discuss and provide guidelines for the application of georeferencing, editing and Kernel Density for a modern John Snow’s map and to provide several inputs for analysing today’s diseases and relative risk factors, also at the light of new functionalities which make it possible to spread the results of the work. Some considerations are also provided regarding the importance of didactical activities adequately thought out and planned and held in geocartographic laboratories or specially equipped GIS lecture halls, since they can contribute to a rigorous geographical education with links to modern sectors of interdisciplinary research. As support for this specific case, the main results are presented of a short questionnaire submitted to the participants at the demonstrative-application course focused on the re-elaboration in a GIS environment of John Snow’s map.