Trends in incidence rates of micro-organisms among patients with bloodstream infections at intensive care units in South Korea from 2011 to 2022: data from the Korean National Healthcare-Associated Infections Surveillance System (KONIS).

BACKGROUND

Trends in the microbiological distribution and incidence rates of multi-drug-resistant pathogens in patients with bloodstream infections (BSIs) in intensive care units (ICUs) were evaluated.

METHODS

This retrospective analysis was conducted using data from the Korean National Healthcare-Associated Infections Surveillance System. Annual trends in micro-organism distributions and multi-drug-resistant pathogens in patients with BSIs were investigated.

RESULTS

The incidence rate of BSI due to Staphylococcus aureus decreased from 33.1 per 100,000 patient-days in 2011 to 9.7 per 100,000 patient-days in 2022. The incidence rate of BSI due to Klebsiella pneumoniae increased from 6.4 per 100,000 patient-days in 2015 to 12.1 per 100,000 patient-days in 2022. The incidence rate of BSI due to meticillin-resistant S. aureus (MRSA) (28.8/100.000 patient-days in 2011; 7.3/100,000 patient-days in 2022) and the percentage of MRSA strains (91.8% in 2011; 76.7% in 2022) decreased throughout the study period. The incidence rate of BSI due to imipenem-resistant K. pneumoniae increased significantly from 0.3 per 100,000 patient-days in 2011 to 6.1 per 100,000 patient-days in 2021, and the percentage of imipenem-resistant K. pneumoniae strains increased from 4.3% in 2011 to 48.5% in 2022. The incidence rate of BSI due to imipenem-resistant Pseudomonas aeruginosa showed an increasing trend from 2011 to 2021.

CONCLUSION

The incidence rate of BSI due to MRSA in ICUs decreased, whereas the incidence rates of BSIs caused by imipenem-resistant K. pneumoniae and imipenem-resistant P. aeruginosa in ICUs showed an increasing trend. Over the past decades, there has been a significant shift from Gram-positive bacteria to Gram-negative bacteria in BSIs.