Chasing the ghost of infection past: identifying thresholds of change during the COVID-19 infection in Spain

Luis Santamaria; Joaquin Hortal

This basic analysis of the growth rates of cases and fatalities evidences the effectiveness of the contention measures taken by Spanish national and regional governments. The confinement of all population that could telework, the suspension of in-class teaching in schools and universities, and the closure of non-essential shops, bars and restaurants resulted in a marked downwards inflection in the curves of both infections and deaths. However, it is also remarkable the existence of an earlier breakpoint, corresponding to a decrease in the rate of infections in the first week of March. This breakpoint was the most consistent (present in the four variables) and the most supported (present in all but one models with one or more breakpoints), suggesting that this was the most important change of dynamic during the period of time analyzed. The dropdown in the rate of infections coincides with an increase of the awareness of the Spanish population (due to the reporting of a rapidly increasing number of cases and deaths, i.e. the delayed perception of the events of phase 1) and the issuing of official recommendations for the prevention and treatment of COVID infections, but precedes the legal enforcement of most social-distancing measures by the regional and central governments (see Figure 5 , Table S1 ). Indeed, it takes place the week before the marked decrease in community mobility registered during the second week of March (from March 8 to March 15) in both Madrid and the whole of Spain (Google 2020) . This suggests that a large proportion of the Spanish population changed their behaviour due to the combination of increasing awareness and the dissemination of preventive hygienic and distancing measures by the government and the media -with recourse to the examples of China, South Korea and Italy. It seems therefore fair to argue that, during this week, the population responded swiftly to the voluntary prevention and distancing measures suggested by the authorities and the media, and these were effective to slow down the early spread of the pandemic.