Symptoms and Signs of Toxoplasmosis

Medical Author:
Medically Reviewed on 3/11/2019

Doctor's Notes on Toxoplasmosis

Toxoplasmosis is a parasitic disease (Toxoplasma gondii), usually asymptomatic, but may become latent and produce symptoms when reactivated, especially in immunocompromised people. People that produce signs and symptoms usually have cervical lymph node swelling and flu-like symptoms that resolve in a few weeks without treatment. However, the parasites stay in the body and reactivate if the person’s immune system fails to keep them suppressed (HIV infection, chemotherapy). Then the parasites may cause vision and hearing damage or loss and brain damage (encephalitis, seizures). Congenital infections can follow a similar course.

Toxoplasma gondii is the protozoan parasite that causes Toxoplasmosis. It can infect most warm-blooded animals (humans, dogs, sheep, pigs, mice, birds) but cats are the only host that allow this parasite to complete its lifecycle; cats shed millions of oocysts in feces for weeks and the oocytes can survive for a year in the environment. Humans and other animals ingest them from contaminated food or water sources. .


Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.