An 11 year Dutch study provides compelling evidence that a move to single rooms from multi-occupancy bays dramatically reduced the burden of multidrug-resistant (MDR) Gram-negative bacteria in the ICU.

The study was centred in a 16 bed ICU in The Netherlands. From 2002-2009, the ICU was composed of a mixture of multi-occupancy bays and single rooms. Then, from 2009-2013 (the end of the study), a new ICU was opened with 100% single rooms. During the period before the move to the new ICU, there were frequent and sustained clusters of clonally related MDR Gram-negative bacteria including Klebsiella, Enterobacter, Serratia, Pseudomonas and Acinetobacter species. After the move to the new ICU, there was a significant reduction in the burden of these bacteria on the ICU, with the total number of MDR Gram-negative bacteria cases falling from around 120 to 20 per 12 month surveillance period.

The authors carefully evaluated the situation to rule out other factors that may have explained this reduction, showing that there were no significant changes in bed occupancy and the number of admissions. However, it is important to note that some important factors that may have explained the reduction could not be measured, for example, compliance with hand hygiene and other basic IPC practices. Also, selective digestive decontamination (SDD) was in use before the more to the new ICU and ceased shortly before the move. Stopping SDD would have reduced the selective pressure for antibiotic resistant bacteria, so could well have contributed to the reduction. Finally, there was no control group to measure the impact of other interventions.

Despite these limitations, this study along with several others, provides evidence that moving to single rooms reduces the transmission of antibiotic resistant bacteria.