A 40-year-old man presents with jaundice and dull abdominal pain for one week and a high-grade, intermittent fever with chills and rigors for two weeks. The pain was initially periumbilical, but became generalized over time; it was unaltered by meals or posture. He is a heavy drinker. There is no history of IV drug abuse or sexual promiscuity. He arrived home three weeks ago, after spending a month in Kenya. His CBC is significant for WBC 14,600/mm3 with 85% neutrophils, Hb 11.9 g/dL, and platelets 130,000/mm3.