When newly infected with toxoplasmosis, most people either at first feel like they have the flu or do not feel sick at all. This is why people rarely know whether or when they've had toxoplasmosis.
A person with an immune system weakened by HIV infection, organ transplant medicines, or lymphoma can develop life-threatening toxoplasmosis. Antibiotic therapy is often used to prevent this from happening, and severe infection requires aggressive treatment.
Severe symptoms vary depending on which part of the body is affected. If the infection is in the:
On rare occasions, seemingly healthy people have been known to develop serious symptoms of toxoplasmosis.1
Citations
WebMD Medical Reference from Healthwise