HealthJuly 18, 2026

oocyst

OH-uh-sist

Definition

A hardy, thick-walled stage in the life cycle of certain parasitic protozoa, which allows them to survive in the environment and remain infectious.

Etymology

The word is derived from the Greek 'oon' (egg) and the Greek 'kystis' (bladder or pouch). It combines these roots to describe the egg-like, protective shell that encases the parasite.

In the news

In the article, the term is used to explain the infectious nature of the parasite, noting that it only takes a few oocysts to cause an illness. It highlights the high risk associated with consuming even trace amounts of contaminated food.

Cyclosporiasis Outbreak 2026

Read the full article ↗

Johns Hopkins Medicine

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