Gram-positive cocci in Dutch ICUs with and without selective decontamination of the oropharyngeal and digestive tract: a retrospective database analysis.

Objectives: The objective of this study was to determine time trends in the rate of Gram-positive cocci in 42 Dutch ICUs that continuously used or did not use selective oropharyngeal decontamination (SOD) or selective decontamination of the digestive tract (SDD) and ICUs that introduced SOD/SDD.

Methods: The Dutch Surveillance System on Antibiotic Resistance was used to determine monthly rates of Staphylococcus aureus, Enterococcus faecalis and Enterococcus faecium isolates, including resistant phenotypes, in blood and respiratory tract specimens from 2008 to 2013. Per patient, the last isolate per species per month was selected, and cumulative rates per 100 beds per month were determined. Time trends were analysed by multilevel Poisson regression.

Results: Eighteen ICUs used SOD/SDD (1296 months), 13 did not use SOD/SDD (936 months) and 11 introduced SOD/SDD (373 months before and 419 months after introduction). There was no significant increase in the rate of Gram-positive cocci in ICUs that used SOD/SDD. Introduction of SOD/SDD was associated with increased rates of S. aureus (β = 0.018, 95% CI 0.006-0.030) and E. faecalis isolates (β = 0.028, 95% CI 0.006-0.051) in respiratory tract specimens. Numbers of resistant phenotypes remained low, and an observed increase in E. faecium isolates (β = 0.033, 95% CI 0.012-0.054), 97% of which were resistant to ampicillin, in the absence of SOD/SDD disappeared after the introduction of SOD/SDD.

Conclusions: In ICUs with a low endemicity of resistance, introduction of SOD/SDD was associated with increased rates of S. aureus and E. faecalis isolates, but not with resistant phenotypes. Continuous 5 year use of SOD/SDD was not associated with increased isolation of Gram-positive cocci.