A 40-year-old man presented with a three-week history of malaise, naus
ea, night sweats, decreased appetite, and a 15-lb weight loss. He repo
rted having had diarrhea, occasionally with bright red blood, for the
first two weeks and a temperature as high as 39.4 degrees C for the la
st two weeks. He had not had cough, shortness of breath, wheezing, che
st pain, arthralgias, rash, or conjunctivitis, He had not eaten raw oy
sters or raspberries.