Plaster-associated Bacillus cereus wound infection. A case report.

Plaster of Paris and nonsterile cast padding have previously been implicated in wound infections. The observation of three pin site infections with Bacillus cereus following pin placement and plaster fixation of an open forearm fracture led to an epidemiologic investigation. Two hundred sixty-one bacterial cultures were taken from materials in the Steinmann pin application and plaster fixation procedures. B. cereus with a similar antibiogram and biotype as was identified in the pin site cultures was recovered from three of the 22 (14%) plaster-impregnated gauze rolls and six of seven (81%) tapwater samples. The Bacillus sp contamination rate of plaster when dry or wetted with sterile water or tapwater was 58%, 25% and 40% respectively. All cultures of plaster samples were negative after steam or gas sterilization. These results suggest that the patient may have acquired the infection from the plaster-impregnated gauze wetted in tapwater. In this case, the Steinmann pins may have facilitated infection by guiding the plaster-associated bacteria to the pin insertion site. The use of gas sterilized plaster materials should be considered in certain circumstances.