Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
H&E-stained section of the lung from a 1918 influenza victim showing a massive infiltrate of neutrophils that fills the alveolar air spaces in early bacterial bronchopneumonia. Alveolar capillary congestion is prominent (original magnification 200×).
