David,

Bill had FUO the 5th week of treatment and was hospitalized. My understanding is that neutropenia (and he was very neutropenic at that point) will also create a fever so that complicates matters. He looked and acted very sick while in the hospital but once released seemed to be so much better than the previous weeks that I think he did have some infection that they did not find (perhaps mouth sores.) Between the antibiotics and the constant IV drip of fluids he did nothing but get better from the end of treatment on.