Surveillance cultures and benefit of laminar airflow units in patients undergoing bone marrow transplantation.

The effectiveness of gastrointestinal and topical decontamination, as well as isolation in laminar airflow (LAF) units were investigated in 20 patients. On a weekly basis, surveillance cultures were taken. Environmental controls were taken on the medical ward outside the two LAF units and from the LAF unit itself when being used by a patient. The use of LAF units seems to be of benefit in preventing exogenous infections, but there are two weak points in the isolation techniques: the opening of the tent (with a free entry into the tent itself) and the water delivery system. By using appropriate decontamination measures, it was possible to greatly reduce the number of bacteria and species of the normal flora in all regions with the exception of the oropharynx. Individual patients with oxacillin resistant coagulase-negative staphylococci and/or Candida albicans continued to show the presence of these organisms during this time. The detection of Clostridium difficile and/or its toxin B in eight patients at the beginning of the individual observation period was significant. Four out of 15 fever episodes were attributable to endogenous bacterial infections. Each of the causative organisms had been previously isolated in the surveillance cultures, thus the clinician was able to initiate a calculated antimicrobial therapy. As evident from the low incidence of infectious complications, gastrointestinal and topical decontamination of the skin as well as reverse isolation in LAF units are efficient protective measures for bone marrow transplant patients.