Covid-19 mortality and local burden of infectious diseases: A worldwide country-by-country analysis

BACKGROUND: Global differences in the Covid-19 death toll between various countries are still a matter of debate. We evaluated the potential influence of general burden of infectious diseases prior to the onset of the Covid-19 pandemic on the number of Covid-19 deaths during the pandemic. METHODS: We used publicly available data from Worldometer and Our World in Data. In a complete case analysis, 178 countries and territories, where all parameters were available, entered the analysis, representing 99.02% of the global population. Relationships between various parameters of the local burden of infectious diseases as well as childhood mortality, median age, and vaccination as independent variables, on Covid-19 deaths as the dependent variable, were evaluated. RESULTS: Death from diarrheal disease, respiratory disease, pneumonia, pneumonia in childhood, malaria, and HIV, as well as childhood mortality correlated negatively with number of Covid-19 deaths (Spearman rank correlation test: p < 0.0001 for each parameter), while median age was positively correlated with Covid-19 deaths (p < 0.0001). In a multivariable approach using kernel functions, death from respiratory disease and median age retained statistical significance. When vaccination rate and median age were simultaneously taken into account, vaccination rate showed a significant negative correlation with Covid-19 deaths. CONCLUSIONS: Local burden of infectious diseases as well as childhood mortality prior to the onset of the pandemic have a strikingly negative impact on Covid-19 deaths. This effect might be due to an increase in trained immunity and to the overall younger population. Vaccination appears as an effective preventive measure.