Introduction

This tool identifies the daily infection risk by COVID-19 for Portugal mainland as well as uncertainty attached to the risk. So, these maps can be used by public health officials to identify local risk areas related to daily rates of infection and to guide surveillance and control activities.  The model was developed by researchers from Centro de Recursos Naturais e Ambiente of Instituto Superior Técnico (CERENA) specialists in Geostatistics and Spatial Data Sciences, as a result of willing to help monitorizing evolution of COVID-19 infection in Portugal.

Risk of infection

COVID-19 infection risk is calculated from the number of new daily infections per municipality as reported by the Portuguese Directorate-General for Health (DGS). The risk is then a result of a stochastic spatial dispersion model of observed infection rates by municipality, taking into account spatial patterns of infection and their uncertainty.

Risk uncertainty

Uncertainty occurs as a result of the noise related to the population size in each municipality. This means that the analysis of infection risk values should always be complemented by the interpretation of uncertainty values. For example, a high risk of infection in a municipality with a small population results in high uncertainty. Thus, the risk value at that location has little relevance.

WebGIS

As a result of this work an interactive webGIS-based tool  is freely available to visualize daily-updated infection risk and uncertainty maps.