Figure 1

Micrographs of lung tissue, pathophysiology, and treatment from a patient with acute respiratory distress syndrome and H7N9 influenza. (A) Two computed tomography images (3 days before admission (day –3) and 14 days after admission (day 14)) and the patient’s last X-ray image (2 days before death (day 25)). (B) Hematoxylin and eosin staining from a normal sample and the H7N9 patient’s lungs. Diffuse alveolar damage, including edema, hyaline membranes, and inflammation, were seen in these images. (C) Masson staining in normal lungs and the H7N9 patient’s lungs. Severe fibrosis (blue) was seen in the H7N9 patient. (D) Immunohistochemical staining with smooth muscle actin in normal lungs and the H7N9 patient’s lungs. Thickened distal pulmonary arteries were seen in the H7N9 patient.