A 6-year-old girl with a history of relapsed AML underwent a myeloablative matched sibling BMT 14 days ago. She is an inpatient in the hospital awaiting engraftment, receiving supportive care with a prophylactic fluoroquinolone antibiotic and transfusions until count recovery, when she suddenly develops fluid-refractory hypotension (blood pressure 70/30 mm Hg). On examination, she is noted to be febrile to 39.6°C and tachycardic at 145 beats/min. She is noted to have crackles on lung auscultation and has a distended but soft abdomen. She is urgently transferred to the PICU where she eventually requires support with multiple vasopressor agents and mechanical ventilation. She is started on broad-spectrum intravenous antibacterial antibiotics and undergoes CT imaging of her abdomen, which identifies colitis. Question: What is the likely underlying etiology of her sudden hemodynamic collapse? Answer: Gram-negative sepsis secondary to translocation of gut bacterial flora.
An 11-year-old boy with an immunodeficiency disorder underwent an HLA matched unrelated BMT. His transplant course was relatively uncomplicated and he had appropriate count recovery. On day 26 after his transplant, he developed high persistent fevers and a gradual change in mental status leading to florid encephalopathy. He was transferred to the PICU after experiencing a short tonic-clonic seizure and inability to maintain his airway. After intubation in the PICU, he underwent a lumbar puncture that revealed CSF findings of 5 WBC, 0 RBC, 96 mg/dl protein, and 47 mg/ml glucose (greater than two-third of the blood sugar level). CSF bacterial aerobic and anaerobic cultures remained negative. He was started on broad-spectrum antimicrobials including empiric antifungal and antiviral agents. Question: What viral infection is an emerging cause of encephalopathy in the HCT population? Answer: HHV6.