The results of our study confirmed the increased frequency of bacteraemic GAS infections in adult patients as well as changes in the demographic and clinical characteristics in the post-pandemic era compared with the years before the COVID-19 pandemic. The incidence of bacteraemic infections caused by beta-haemolytic group B, C, F and G streptococci in adults was more or less stable in both periods.
The reasons for the increased incidence of iGAS infections shortly after the end of the pandemic are not fully understood. The most likely explanation is a decrease in the activity of human immunity against streptococci resulting from reduced human-to-human transmission of streptococci during the COVID-19 pandemic. This hypothesis is supported by similar trends observed in other droplet-transmitted infections, both viral…