Point-of-use filtration method for the prevention of fungal contamination of hospital water.

Published data implicate hospital water as a potential source of opportunistic fungi that may cause life-threatening infections in immunocompromised patients. Point-of-care filters are known to retain bacteria, but little is known about their efficacy in reducing exposure to moulds. We investigated the effect of point-of-use filters (Pall-Aquasafe) on the level of contamination of Aspergillus fumigatus and other filamentous fungi. The point-of-use filters were applied to several outlets (taps and showers) on the paediatric bone marrow transplantation (BMT) unit of the National Hospital in Oslo, Norway. In addition the efficacy was investigated using a test rig. The laboratory experiments showed that the filters were highly effective in reducing the number of colony-forming units for a period of at least 15 days. In the BMT unit the filters eliminated the fungi from the water on day 1 but due to particles present in the water the filters occluded, which prevented further evaluations. Our results show that point-of-use filtration might be an effective preventive measure to eliminate filamentous fungi at individual points of water use, thereby reducing patients' exposure.