There is circumstantial evidence that SARS-CoV-2 infections emerged in Europe even before the official start date of the pandemic, i.e. before the turn of 2019-2020, as evidenced by studies of the incidence of excess mortality in more than 900 regions of the continent in 2019.

“We do not have hard evidence, but we certainly have sufficient empirical basis to formulate such hypotheses”, says Professor Przemysław Śleszyński of the Institute of Geography and Spatial Planning of the Polish Academy of Sciences, one of the authors of the study, which shows that mortality in the ‘pre-pandemic’ period in 44 regions of Europe (out of the 918 covered by the study) was significantly higher than in the corresponding period in 2016-2018.

Particularly interesting is the case of the French department of Territoire de Belfort, where the average death rate remained high for a long period of the period analysed, at 148-151 % of previous years’ values, and reached a record high of 204 % in the week between 28 November and 4 December 2019. This region was one of the first in which the COVID-19 epidemic was detected and one of the most severely affected by it in the winter and spring of 2020. The same happened in Lombardy and the Madrid metropolitan area, 

The research method used by the Polish researchers involved collecting demographic data on deaths by consecutive week that occurred between October 2019 and March 2020 in European NUTS3 regions (a sub-region made up of several counties) with a population of more than 100,000 people. In total, nearly 1,000 were checked. The information obtained was then compared with data from the previous three years.

The Polish study is not the only one suggesting a much earlier appearance of the SARS-CoV-2 virus in Europe. Numerous research groups have repeatedly analysed its potential evolution on the basis of wastewater monitoring, which is one of the best methods of tracking epidemics in different areas.

Arkadiusz Słomczyński