4. Spatial dissemination and global momentum of the epidemic
The emergence of the COVID-19 pandemic is an ongoing question that continues to fuel scientific debate. In Europe, the epidemic initially spread from clearly identified clusters that may be considered as the epicentres of the first wave. Mortality rates were high in these areas, declining concentrically moving away from them.
Italy was the first European country to be strongly impacted by the pandemic, leading to a lockdown in the north of the country on 8 March 2020, followed by the rest of the country the day after. In the first wave, half of the deaths were recorded in Lombardy. Bergamo and Milan were considered as the major epicentres, the virus having been spread in the latter at a European football match played on 19 February.
Other European countries followed in Italy’s footsteps one by one. In France, where a total lockdown was implemented on 17 March, the pandemic was particularly virulent in the Grand-Est region, attributable notably to a religious gathering in the Haut-Rhin department held from 17 to 21 February 2020. The epidemic was also extremely virulent in Ile-de-France.
In Germany, where stringent social restriction measures were introduced on 17 March, first-wave mortality was the highest in the south, and notably in Bavaria. This phenomenon can be ascribed to geographical proximity to Italy and eastern France, which were substantially impacted.
The question today is not the date on which the pandemic started in each country but the successive waves of the spread of the virus. These waves correspond to numerous factors, such as social restriction measures, climate, and the emergence of faster-spreading variants. These aspects led to the emergence of new waves in an almost simultaneous fashion, the second wave in autumn 2020 hitting France, Germany, the UK, Portugal, and Italy at the same time. These factors also led to the emergence of new waves in a non-synchronous manner, with the third wave in early 2021 peaking in the UK in January, Portugal and Spain in February, Italy at the start of April, and France and Germany at the end of April. This asynchronous dissemination can be attributed to the differentiated dissemination of the Alpha variant in Europe. The same applies to the fourth wave, in summer 2021, though this time with the Delta variant.
While the data provided on this site should be used with caution when comparing daily death numbers, they may be harnessed to better understand the momentum of the epidemic in each country and to date the minimum and maximum spread of COVID-19. Data on mortality by age can also be used to examine the impact of vaccinations on the lethality of the virus.