Pathology and Pathogenesis of SARS-CoV-2 Associated with Fatal Coronavirus Disease, United States

Martines, Roosecelis B.; Ritter, Jana M.; Matkovic, Eduard; Gary, Joy; Bollweg, Brigid C.; Bullock, Hannah; Goldsmith, Cynthia S.; Silva-Flannery, Luciana; Seixas, Josilene N.; Reagan-Steiner, Sarah; Uyeki, Timothy; Denison, Amy; Bhatnagar, Julu; Shieh, Wun-Ju; Zaki, Sherif R.

An ongoing pandemic of coronavirus disease (COVID-19) is caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Characterization of the histopathology and cellular localization of SARS-CoV-2 in the tissues of patients with fatal COVID-19 is critical to further understand its pathogenesis and transmission and for public health prevention measures. We report clinicopathologic, immunohistochemical, and electron microscopic findings in tissues from 8 fatal laboratory-confirmed cases of SARS-CoV-2 infection in the United States. All cases except 1 were in residents of long-term care facilities. In these patients, SARS-CoV-2 infected epithelium of the upper and lower airways with diffuse alveolar damage as the predominant pulmonary pathology. SARS-CoV-2 was detectable by immunohistochemistry and electron microscopy in conducting airways, pneumocytes, alveolar macrophages, and a hilar lymph node but was not identified in other extrapulmonary tissues. Respiratory viral co-infections were identified in 3 cases; 3 cases had evidence of bacterial co-infection.