Lung - nontumor
Toxoplasma gondii

Author: Elliot Weisenberg, M.D. (see Authors page)

Revised: 28 February 2017, last major update September 2011

Copyright: (c) 2003-2017,, Inc.

PubMed search: Toxoplasma gondii [title] pulmonary

Cite this page: Toxoplasma gondii. website. Accessed October 15th, 2018.
Definition / general
  • Associated with AIDS, immunosuppression including therapy and hematologic malignancy
  • May be transmitted in utero
  • Ubiquitous intracellular coccidian parasite that causes focal parenchymal necrosis, diffuse interstitial pneumonia
  • Cats are definitive hosts, humans are intermediate
  • Very high prevalence in France; in US, from 3% to 20% depending on geography, ethnic group
  • Humans acquire transmission from ingestion of material contaminated with cat feces or cysts contained in undercooked meat (pork, beef, mutton); infection may be acquired in utero
  • Most disease in CNS, eye and heart; pulmonary involvement is in 70% of disseminated cases
  • Pulmonary involvement is indicative of disseminated disease and risk of death from CNS disease or bronchopneumonia
  • May cause severe morbidity or death in affected neonates
Gross description
  • Lungs heavily congested, combined weight approximately 2000 grams
Microscopic (histologic) description
  • Organisms present in histiocytes, alveolar lining cells, endothelial cells and pseudocytes abundant in necrotic areas
Positive stains