Eradication of a resistant Pseudomonas aeruginosa strain after a cluster of infections in a hematology/oncology unit.

OBJECTIVES: This report chronicles an outbreak of a multiply resistant strain of Pseudomonas aeruginosa and the measures required to contain this outbreak. METHODS: Laboratory-based ward-liaison surveillance allowed the detection of a multiply resistant strain of P. aeruginosa infecting patients in our hematology/oncology unit. Sampling of the immediate environment was carried out. Pulsed field gel electrophoresis was used to compare the patients' organisms with those found in the environment. Extensive dismantling of the drainage system, repeated cleaning and disinfection, and a review of the departmental antibiotic policy were some of the infection control measures instigated. RESULTS: During a period of 11 months, three patients in the hematology department and two patients in the oncology department were infected with multiply resistant P. aeruginosa. There were two cases of pneumonia, one of which was fatal, and two cases of neutropenic septicaemia. Pulsed field gel electrophoresis performed on the isolates showed that the isolates from geographically separate areas could be divided into two strains that were closely related but distinct. Two genotypically identical strains were also isolated from the plumbing systems in the areas of each ward where patients had been treated. CONCLUSIONS: The potential for serious nosocomial infections with P. aeruginosa is well recognized. Eradication of the organism from the environment may require the co-ordinated efforts of clinicians, nurses, pharmacy and hospital engineers, working in collaboration with the hospital infection control team. To date, the same strains have not been isolated despite repeated surveillance over the past 18 months and therefore these measures have, in our opinion, successfully removed the potential for nosocomial infection with this resistant organism in our hospital.

Cross infection in an intensive care unit by Klebsiella pneumoniae from ventilator condensate.

Klebsiella pneumoniae serotype K28 was cultured from six patients over 5 weeks in a general Intensive Care Unit. Colonized condensate in the ventilator expiratory water traps was the probable source of the organism, and hand carriage the vehicle of transmission. Although the cross-infection hazard of ventilator tubing condensate is recognized, there is no report in the literature of an outbreak caused by such fluid. Ventilator tubing condensate should be viewed as contaminated clinical waste and dealt with accordingly.