A 13-year-old girl with a history of relapsed acute lymphoblastic leukemia (ALL) underwent an UCT 6 months ago. She is engrafted without evidence of GVHD and is no longer receiving immunosuppression. She presents to the emergency department with a fever of 40.1°C and tachypnea. Her saturations are 88% while breathing room air so she is placed on low flow oxygen via nasal cannula. On examination, she is in obvious distress with increased work of breathing and decreased breath sounds in the left lower lung base with rhonchi. A chest radiograph is obtained which shows a large opacity in the left lower lung field with air-bronchograms and trace pleural effusion. Question: What vaccine-preventable infection should be considered? Answer:\nStreptococcus pneumoniae.
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.