 In humans with a normal immune system, it is an extremely common silent infection.Identified by methenamine silver stain of lung tissue, type I pneumocytes, and type II pneumocytes over-replicate and damage alveolar epithelium, causing death by asphyxiation.Fluid leaks into alveoli, producing an exudate seen as honeycomb/cotton candy appearance on hematoxylin and eosin-stained slides.