Toxoplasmosis. Are cats really the source?
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Updated: Oct 3, 2026

Obtaining Highly Purified Toxoplasma gondii Oocysts by a Discontinuous Cesium Chloride Gradient
Published on: November 3, 2009
1Prince of Wales Hospital, Randwick, New South Wales.
Background:
Toxoplasmosis is a zoonotic infection caused by the parasite Toxoplasma gondii. It would appear to be one of the commonest human infections, but is usually asymptomatic. It is only problematic if the patient is pregnant or immunosuppressed.
Objective:
To discuss the epidemiology, clinical features, diagnosis, treatment and prevention of toxoplasmosis.
Discussion:
Cats have long been blamed for playing a major role as the reservoir of this infection. To some extent, this is true, although contact with infected raw meat is probably a more important cause of human infection in many countries. Direct contact with pet cats is also a less common risk factor for infection than ingestion of the oocyst from faecally contaminated hands (often via soil).
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