Explaining COVID-19 contagion in Portuguese municipalities using spatial autocorrelation models

EnglishThis paper investigates the pattern of COVID-19 contagion in Portuguese municipalities from March 23rd to April 5th (the exponential phase). We have recurred to spatial autocorrelation models to discuss how the conglomeration of highly infectious spaces has also contributed to infecting neighbouring municipalities. We have used several indicators for the contagion of COVID-19 from the number of infectious individuals to rates of infectious. As explicative variables, additionally to spatial proximity, we also considered population density, the share of the elderly population as well as the length of municipal perimeter/border. Our results show that highly dense municipalities tended to contaminate close areas. Lengthier perimeters also showed a positive effect on the contagious indicators for a given municipality. galegoEste artigo investiga o patron de contaxio da COVID-19 nos municipios portugueses entre o 23 de marzo e o 5 de abril (a fase exponencial). Recorremos a modelos de autocorrelacion espacial para analizar como a vecinanza de espazos altamente infecciosos tamen contribuiu a infectar os municipios proximos. Utilizamos varios indicadores para o contaxio da COVID-19, desde o numero de individuos infecciosos ata as taxas de infeccion. Como variables explicativas, ademais da proximidade espacial, tamen consideramos a densidade de poboacion, a proporcion da poboacion de persoas maiores e a lonxitude do perimetro/fronteira municipal. Os nosos resultados indican que os municipios altamente densos tenden a contaminar areas proximas. Os perimetros mais longos tamen mostraron un efecto positivo nos indicadores contaxiosos para un municipio determinado.