In 2019-2020, we conducted a set of case studies devoted to the investigation and design of a methodology for GIS-based support of medical administration and planning on a city scale when accounting and controlling infectious disease. The studies were conducted for the administrative territory of St. Petersburg city (Russia), and were based upon the medical statistics data collected and accounted by St. Petersburg medical administration. The statistics included data on tuberculosis, human immunodeficiency virus and hepatitis infection. All the medical data used in the study are impersonalized. GIS-based MDMS prototype was developed upon the QGIS software. Moving forward in the previously formed study direction, now we are working on MDMS interface redesigning to facilitate its usability. Current activities are focussed on incorporation of the Web interface into previously developed MDMS prototype. The paper discusses development of the Web GIS interface prototype, and poses feature research and development aims. First feedback collected from medicals makes it possible to pose a Web-GIS-based MDMS as more flexible and easy to use, in comparison to the desktop-GIS-based.