Nosocomial Infection Caused by Xanthomonas maltophilia A Case-Control Study of Predisposing Factors

Abstract

Factors predisposing to clinically significant nosocomial infection with Xanthomonas maltophilia were examined in a matched case-control study using multivariate techniques. Sixteen cases occurred among cancer patients in a six-month period, including an apparent cluster of three cases in an intensive care unit. These infections were unusually serious; eight patients had disseminated infection caused by X maltophilia and six died as a result of their infections. Among the 64 factors that were examined, therapy with broad-spectrum antibiotics and central venous catheterization were found to significantly increase susceptibility to infection. Therapy with imipenem was more than ten times more frequent among cases than among controls (p<.001). All fatal infections occurred in patients who had received imipenem, including two patients who died before the organism could be identified and appropriate therapy instituted. Infection with X maltophilia should be suspected in patients who develop superinfection while receiving imipenem, and prompt therapy should be instituted to improve chances of survival. Because a common environmental source of X maltophilia was not identified, further study is necessary to determine specific preventive measures.