Microbial colonization and infectious complications in bone marrow transplant recipients treated in strict protective isolation.

Bone marrow transplantation was carried out in 10 patients (5 with acute leukemia and 5 with aplastic anaemia). Protection against endogenous and exogenous infection was attempted by a rigorous sterile protective isolation regimen, comprising laminar-air-flow cabinets, daily decontamination of skin, mucous membranes and intestines. All supplies of food, fluids, medicine and equipment were sterilized. In all patients a heavy suppression of the normal bacterial flora was obtained after approximately 1 week and 85% of a total of 1026 days of decontamination revealed only scanty growth in one or a few regions of the patients. The surviving microorganisms were Candida albicans and non-pathogenic commensals (mainly Staphylococcus albus). In 1 patient only an exogenic microorganism was introduced possibly by transfusion or staff. 16 febrile episodes were recorded in the patients during decontamination covering 21% of the period. Four episodes were caused by bacteria (Klebsiella pneumoniae, Pseudomonas aeruginosa and mixed). In most of the remaining episodes the etiology was not established. The results thus show that endogenous pathogenic bacteria can be eradicated by the regimen, and that systemic antimicrobial chemotherapy can be restricted and guided by the results of the previous and contemporary cultures. However, viral infections remain a major problem in these patients. Efforts should be maintained to avoid entrance of exogenic bacteria by staff and supplies.