[The surveillance of infectious diseases: the experience of Open Data COVID].

Objectives: to describe Open Data Covid, an online application dedicated to the pandemic and the health of the population of the province of L'Aquila (Abruzzo Region, Southern Italy), created following the health emergency in Italy and worldwide.

Design: Open Data Covid is the result of a multidisciplinary study group including University of L'Aquila, Local Health Unit 1 Abruzzo, and Gran Sasso Science Institute. In the first phase, the information to be shown was identified and made available based on the pandemic national reports to obtain comparable results. The health databases containing the information needed to power the application were selected. This information was then evaluated, cleaned, and integrated.

Setting And Participants: data derived from administrative data flow of the Local Health Unit.

Main Outcomes Measures: the final application collects individual data from confirmed laboratory cases of SARS-CoV-2 infection and collects information about their residence, laboratory diagnosis, hospitalization, clinical status, risk factors and outcome.

Results: the application was structured in three sections. The first section shows data about the COVID-19 pandemic; the second contains information about the assisted population; the third contains documentation and access to public Application Programming Interfaces (APIs) for accessing source data. Consulting the application data is simple and intuitive: through graphs and infographics, the temporal and geographical course of the pandemic can be known.

Conclusions: the Open Data Covid application is a response to the information gaps highlighted by the COVID-19 pandemic. Its creation demonstrated that is possible to build an online application useful both for the population and for public health professionals.