Forty children with hematological malignancies, who underwent allogeneic hematopoietic stem cell transplants between September 1994 and May 2001, were divided into 2 groups according to their infection control procedure; the standard protective isolation and the efficient protective isolation groups. Efficient protective isolation procedures included well-cooked foods and oral prophylaxis with new quinolones and antifungal drugs, while inhalation of antibiotics and antifungal drugs was suspended. We then compared the febrile index (= X/Y) [febrile period (X) of > 38.5 degrees C and the days (Y) with a post-transplant neutrophil count < 500/microliter] between the two groups. We discovered no significant difference between the febrile index of the two groups (0.25 vs. 0.38, p = 0.08), regardless of the type of transplantation (0.36 vs. 0.38, p = 0.14). The efficient protective isolation procedure was therefore feasible in this clinical setting.