Case 62

1. Presented by Dr. Mark Hopkins and Dr. Sean Zhang

Clinical history: An elderly patient with multiple comorbidities requiring routine clinical visits presented with worsening confusion and weakness. The patient's recent medical history was negative for fevers, diarrhea, constipation, or any respiratory illnesses. On arrival to the emergency department, the patient was somnolent and confused. The patient was afebrile, tachycardic, and tachypnic on supplemental oxygen via nasal cannula. On physical exam, the patient was alert and oriented x0 (could not tell name, location, current date, or reason for being in ER), and had crackles bilaterally in the lung bases with coarse breath sounds. A chest x-ray demonstrated bilateral infiltrates consistent with COVID-19 infection. Initial labs were significant for a mild leukocytosis (WBC 13.3k), elevated lactate (7.5 mmol/L) and evidence of diabetic ketoacidosis (glucose 626 mg/dL, beta hydroxybutyrate 24 mg/dL, anion gap 39). The patient subsequently tested positive for COVID-19 and was immediately placed on BiPAP for respiratory distress and an insulin drip for ketoacidosis, which rapidly corrected. The patient was later intubated for respiratory distress and worsening leukocytosis (23.2 K/ cu mm). A CT scan demonstrated a thick-walled cavitary lesion in the left upper lobe. An organism was recovered from an endotracheal aspirate.

What is the most likely pathogen?