Cleaning and disinfection of hospital floors.

Hospital floors become contaminated by settlement of airborne bacteria, by contact with shoes, trolley wheels, and other solid objects, and occasionally by the spilling of urine, pus, sputum, and other fluids. Pathogens commonly present on the floor include Staphylococcus aureus dispersed by patients and staff, and (in much smaller numbers) Gram-negative rods, such as Pseudomonas aeruginosa. Spores of Clostridium tetani and gas-gangrene bacilli are also present on floors, probably deposited in larger numbers from shoes and trolley wheels than by deposition from the air. Some of the bacteria lie loosely in dust, while others are ingrained into the surface and between cracks. The removal of this reservoir is one of the normal aims in the control of hospital infection. Dispersal of bacteria into the air has been greatly reduced through the replacement of brooms by vacuum cleaners in wards (Rogers, 1951 ; Bate, 1961 ; Babb, Lilley, and Lowbury, 1963), but vacuum cleaners and also oiled mops do not remove a large proportion of the bacteria from floors (Babb et al., 1963). Scrubbing and disinfection might be expected to have a larger effect, and useful results of disinfection are reported by Foster (1960). Finegold, Sweeney, Gaylor, Brady, and Miller (1962) and Vesley and Michaelsen (1964), on the other hand, have reported no significant difference in the reduction of bacterial counts on floors washed with detergents or with disinfectants. We describe here a comparison of alternative methods of disinfecting and cleaning ward floors. The prompt recontamination of disinfected areas, and the consequent need to