Bacterial contamination of domestic kitchens over a 24-hour period.

This study investigates changes in levels of bacterial contamination at five key sites in ten domestic kitchens during a period of 24 hours. Microbiological swabs were used to provide an aerobic colony count and an Enterobacteriacea count. A record was kept of cooking, cleaning and other activities within the kitchen. Contamination levels varied during the day, peaking after meal preparation and generally falling overnight. There was also indirect evidence of cross contamination, particularly from hands to other surfaces. Levels of microbiological contamination were lower in vegetarian than non-vegetarian households. A variety of data showed that non-food preparation activities also take place in the kitchen. These could also introduce bacterial contamination into the kitchen and facilitate their spread. The results demonstrate the importance of cleaning the kitchen immediately after food has been prepared, focussing on high risk areas such as work surfaces, chopping board, taps and other hand contact surfaces. British Food Journal. 2005;107(7)453-66.