DISEASE CHARACTERISTICS: Leukemia, lymphoma, or Hodgkin's disease OR Stem cell transplantation or bone marrow transplantation (allogenic or autologous) for a neoplastic disease Absolute granulocyte count no greater than 1,000/mm3 anticipated to fall below 500/mm3 within 24-48 hours, and expected to last for longer than 7 days from onset of fever Fever (i.e., oral or axillary temperature at least 38.5 degrees C or 101.3 degrees F once, or at least 38 degrees C or 100.4 degrees F on two or more occasions separated at least by 1 hour during a 12 hour period) Presumed infection