Bacterial colonization of intravascular catheters and anergy to recall skin antigens.

The skin reactivity of 46 ICU patients was tested against recall antigens: mumps, candidin, streptokinase-streptodornase, and purified protein derivative of tuberculin. At the same time, the intravascular catheters used in these patients were cultured with a semiquantitative method. Twelve patients did not react to any of the antigens. There was a statistically significant association between anergy in skin testing and lethal outcome of the current illness. Catheter cultures from 11 patients yielded over 15 colony-forming units of bacteria. No association was found between positive catheter cultures and skin reactivity to any of the antigens. This indicates that catheter colonization is independent of host factors reflected by skin testing and supports the view that transmission of microorganisms into catheters is more important than poor host defense in the initiation of catheter-related infections.