Indolent epidemic of Pseudomonas cepacia bacteremia and pseudobacteremia in an intensive care unit traced to a contaminated blood gas analyzer.

An epidemic of Pseudomonas cepacia bacteremia and pseudobacteremia occurred in the medical intensive care unit at the Clinical Center of the National Institutes of Health. Sixteen patients in the intensive care unit became colonized or infected with this organism in a 21-month period; whereas P. cepacia had been isolated only 16 times in the preceding 90 months from the entire hospital. Further analysis demonstrated a significant association of the epidemic cases with bloodstream isolation of the organism (p less than 0.001, Fisher's exact test). Mortality associated with bacteremia caused by P. cepacia was 38 percent. Intensive investigation of the intensive care unit and its surrounding environment eventually demonstrated that a blood gas analyzer in a satellite laboratory adjacent to the intensive care unit was the reservoir for the outbreak. Replacement of the machine resulted in termination of the outbreak, P. cepacia continues to represent an environmental threat to hospitalized patients.