Entry criteria are: In the ICU for >2 days AND systemic antibiotics >2 days OR central venous catheter for >days AND at least two of the following: total parenteral nutrition, dialysis, surgery, pancreatitis, receipt of corticosteroids, receipt of other immunosuppressive agents. In addition, patients must have a clinical sign of infection (either one of the following): fever, hypothermia, hypotension, unexplanied acidosis, or unexplained elevation in C-reactive protein.