The source of bacterial contamination leading to infection of clean operative wounds has long been a point of discussion among surgeons. Although many possible sources of contamination have been identified, the significance of each has been difficult to assess because of a wide variability in host resistance and bacterial virulence.
The epidemiology of this problem has been under study in our laboratories for several years. These studies have shown that organisms which cause infections in clean operative wounds are seldom found in the air of the operating room1 or in the noses and throats of personnel. Relatively small numbers of these organisms ordinarily gain access to clean surgical wounds through the air providing the operating room is relatively clean and accepted masking techniques are used.2 These bacteria, however, are found in large numbers in the hospitalized patients who harbor an established infection1 and in an occasional carrier.