Impact of the COVID-19 Pandemic on Community Consumption of Antibiotics for Systemic Use and Resistance of Invasive Streptococcus pneumoniae in Slovenia

The present study aims to investigate the impact of the COVID-19 pandemic on community antibiotic consumption and the resistance of invasive Streptococcus pneumoniae (2015-2022) to penicillin in Slovenia. During the pandemic in 2020 and 2021, the total use of antibiotics for systemic use decreased by 23.5% and 24.3%, expressed in defined daily doses per 1000 inhabitants per day (DID), while the use of penicillins, macrolides and broad-spectrum penicillins decreased by 30%, 20% and by 17.5%, respectively, and that of broad-spectrum macrolides fell by 17.1%. The incidence of invasive pneumococcal diseases (IPD) in Slovenia had a large decline during the pandemic. Decreased resistance to macrolides was significantly associated with decreased use of macrolides, while for penicillins the correlation could not be statistically confirmed. The proportion of PCV13 serotypes in IPD in Slovenia decreased after the introduction of the vaccine in the national programme, falling from 81.6% in 2015 to 45.5% in 2022. We noticed a decrease in the serotypes 1, 14, 9V, 7F, 4, 6A and an increase in the serotypes 3, 8, 22F, 11A, 23A and 15A. National interventions during the COVID-19 pandemic substantially decreased outpatients' antibiotic consumption, as well as incidence and resistance of invasive S. pneumoniae.