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 9-year-old boy with a history of cerebral adrenoleukodystrophy (c-ALD) underwent an UCT approximately 18 months ago. His HCT course was complicated by autoimmune cytopenias for which he received multiple therapies over the last year including rituximab, IVIG, mycophenolate mofetil (MMF), daratumumab, and steroids. He presented to the ED with increased work of breathing and oxygen saturation of 86% while breathing room air. On auscultation of his lungs, he had poor aeration bilaterally and copious coarse breath sounds. His Covid-19 testing was negative. He was transferred to the PICU for respiratory support. At the time of admission, he was not on any prophylactic antimicrobial agents. Question: What is the likely underlying etiology of his sudden respiratory distress? Answer:\nPneumocystis pneumonia.