Abnormal findings during initial examination were blood pressure 70/40 mm Hg, heart rate 96 beats/minute, and generalized crackles heard on lung auscultation. Hematologic, biochemical, and arterial blood gas results from samples obtained at admission (while the patient received 100% oxygen by mechanical ventilation) are summarized in the Table. Chest radiographs showed extensive dense pulmonary consolidations. The patient received dopamine, ceftriaxone, azithromycin, and oseltamivir. Culture of blood collected at admission grew methicillin-susceptible Staphylococcus aureus; tracheal aspirate results were negative, and cloxacillin was administered. The patient received ventilatory support with synchronized intermittent mandatory ventilation with a positive end-expiratory pressure of 10 cm H2O. On February 13 she was given methylprednisolone, which was discontinued on February 20 and replaced with oral prednisone on February 21. Ventilatory requirements gradually decreased, and she was extubated on February 22, after blood results normalized and oseltamivir was discontinued. However, on February 23, a low-grade fever and Pseudomonas aeruginosa bacteremia were found, and the patient was given meropenem and piperacillin-tazobactam. On February 28, her respiratory symptoms and fever recrudesced after discontinuation of oral prednisone. On the same day, oseltamivir and prednisone were given along with inhaled zanamivir, intravenous cefepime, and ciprofloxacin; her condition gradually improved. On March 7, oseltamivir and zanmivir were discontinued; on March 13, the patient was considered well and was discharged with a tapering dose of prednisone. She returned to China on March 16. A time line of her travel and hospital course is detailed in the Figure.