Press Release: Impact of lockdown on Covid-19 case fatality rate and viral mutations spread in 7 countries in Europe and North America

Maria Pachetti, Bruna Marini, Fabiola Giudici, Francesca Benedetti, Silvia Angeletti, Massimo Ciccozzi, Claudio Masciovecchio, Rudy Ippodrino, & Davide Zella.

Severe acute respiratory syndrome CoV-2 (SARS-CoV-2) caused the first coronavirus disease 2019 (COVID-19) outbreak in China and has become a public health emergency of international concern. SARS-CoV-2 outbreak has been declared a pandemic by WHO on March 11th, 2020 and the same month several Countries put in place different lockdown restrictions and testing strategies in order to contain the spread of the virus.


Figure 1 a Calculated case fatality rate curves for USA, Italy, Sweden, Germany, Spain, France and UK as explained by Baud and colleagues [11]. Bars indicate the 95% of confidence interval. b Case fatality rate of a normalized by the ρ factor, i.e. by the number of PCR tests performed per 1 M population over positive cases per 1 M population up to the 30th of April, 2020. Bars indicate the 95% of confidence interval. The normalization leads to the formation of three main groups: group 1 includes Germany, group 2 includes Italy, USA and Spain and group 3 includes UK, France and Sweden.


Table 1 Country-specific data showing number of PCR tests and cases per million inhabitants and corrective factor ρ = a/b.


Figure 2 Bubble plot representation of the 30th of April Case Fatality Rate (a) and of the 30th of April Normalized Case Fatality Rate of USA (in light blue), Italy (in red), of UK (black line), France (in magenta), Spain (in green), Sweden (in yellow) and Germany (in cyan). In a, the CFRs are distributed within a large range of values, whereas in b the normalized CFRs values are clustered in three well-distinct groups: Germany forms the first group, Italy, Spain and USA the second group and, finally, Sweden, UK and France the third group with the higher normalized CFR value.

Table 2 Sequenced genomes selection for different geographic areas and time of collection.


Table 3 SARS-CoV-2 recurrent mutations occurrence over time, divided per geographic area. The graph reports evolution of nonsynonymous (top) and silent (bottom) mutation patterns from January 2020 to April 2020 in Italy, Spain, France, Germany, UK, Sweden and in the USA. The frequency of each mutation in each country and for each month was normalized to 100%, i.e. to the total number of genomes analyzed in that frameshift and collected in that specific country. Recurrent nonsynonymous mutation pattern is characterized by the occurrence of mutations at nt14408, nt 23403 and nt28881–28882–28883 (RdRp and spike protein, respectively), while the most found silent mutations are at nt241 and nt3037 (localized in the leader protein and in the nsp3).


Journal of Translational Medicine dd 02.09.2020: 'Impact of lockdown on Covid-19 case fatality rate and viral mutations spread in 7 countries in Europe and North America'

Last Updated on Tuesday, 08 September 2020 19:06