Scientists Uncover Diverse Strains in Brain Parasite

UC Riverside team finds Toxoplasma gondii cysts contain multiple distinct subtypes of parasites

Jan. 27, 2026 at 9:47pm

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A University of California, Riverside team of scientists has found that Toxoplasma gondii, a common parasite affecting up to one-third of the global population, is far more complex than previously believed. The findings, published in Nature Communications, offer new insight into how T. gondii causes disease and why it has been so difficult to treat.

Why it matters

The discovery that Toxoplasma gondii cysts contain multiple distinct subtypes of parasites, rather than a single uniform type, challenges the long-held understanding of the parasite's life cycle. This new knowledge could lead to more effective treatments for toxoplasmosis, a serious disease that can cause neurological damage and vision loss, especially in people with weakened immune systems.

The details

Using advanced single-cell analysis techniques, the UC Riverside team found that each T. gondii cyst contains multiple distinct subtypes of parasites, each with different biological roles. Previously, scientists believed the cysts contained a single, uniform type of parasite lying dormant until reactivation. The researchers discovered that the cyst is an "active hub" with different parasite types geared toward survival, spread, or reactivation.

  • The study was published on January 28, 2026.

The players

Emma Wilson

A professor of biomedical sciences in the UCR School of Medicine who led the study.

Michael W. White

A co-corresponding author of the paper.

Toxoplasma gondii

A common parasite affecting up to one-third of the global population.

University of California, Riverside

The institution where the research was conducted.

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What they’re saying

“We found the cyst is not just a quiet hiding place — it's an active hub with different parasite types geared toward survival, spread, or reactivation.”

— Emma Wilson, Professor of biomedical sciences, UCR School of Medicine

“Our work changes how we think about the Toxoplasma cyst. It reframes the cyst as the central control point of the parasite's life cycle. It shows us where to aim new treatments. If we want to really treat toxoplasmosis, the cyst is the place to focus.”

— Emma Wilson, Professor of biomedical sciences, UCR School of Medicine

What’s next

The researchers hope their findings will lead to the development of new, more precise treatments for toxoplasmosis that can target the different parasite subtypes within the cysts.

The takeaway

The discovery that Toxoplasma gondii cysts contain multiple distinct subtypes of parasites, rather than a single uniform type, represents a significant advancement in the understanding of this common and often symptom-free infection. This new knowledge could pave the way for more effective therapies to combat the serious neurological and vision-related complications that can arise from toxoplasmosis.