A 3-year-old immunocompromised male who had been hospitalized for 7 months in the cardiac intensive care unit developed fever and tachycardia in December. He was prenatally diagnosed with hypoplastic left heart syndrome and received right ventricle to pulmonary artery conduit surgery days after delivery. Due to worsening right ventricular function, after a hemi-Fontan procedure, he received an orthotopic heart transplant at the beginning of his 3rd year of life. His posttransplant course was complicated by multiple episodes of rejection, cytomegalovirus (CMV) pneumonitis, and several central-line-associated bloodstream infections. As a result of the rejection, necessitating plasmapheresis as well as frequent blood draws for management, which led to anemia, he received 36 packed red blood cell transfusions over the course of 7 months posttransplantation. These transfusions were evenly spaced, and he remained hospitalized during the 7 months. At the time of the febrile episode, he was on caspofungin, trimethoprim-sulfamethoxazole, and ganciclovir. The subsequent diagnostic workup included multiple sets of blood cultures, a urine culture, and a CMV viral load analysis. He was started on vancomycin and cefepime while awaiting microbiologic results. Other pertinent test results included a complete blood count (CBC) with differential showing pancytopenia and an aspartate transaminase (AST) level of 200 U/liter (reference range, 20 to 60 U/liter), an alanine aminotransferase (ALT) level of 84 U/liter (reference range, 5 to 45 U/liter), and a C-reactive protein level of 3.1 mg/dl (reference range, 0 to 0.9 mg/dl), which increased to 7