To determine effect of negative air ions on colonisation/infection with methicillinresistant Staphylococcus aureus (MRSA) and Acinetobacter species in an intensive care unit.

Design: Prospective single-centre cross-over study in an adult general intensive care unit. Patients: 201 patients whose stay on the unit exceeded 48 hour’s duration. Intervention: Six negative air ionisers were installed on the unit but not operational for the first 5 months of the study (control period).

Devices were then operational for the following 5.5 months. Measurements and results: 30 and 13 patients were colonised/infected with MRSA and Acinetobacter spp., respectively, over 10.5 months. No change in MRSA colonisation/infection was observed compared with the 5 month control period. Acinetobacter cases were reduced from 11 to 2 (p = 0.007).

Conclusion: Ionisers may have a role in the prevention of Acinetobacter infections.

Air-ionisation-and-colonisation-infection (PDF)