Oocysts of Toxoplasma gondii are shed in cat feces and can contaminate soil. Which form is shed?

• A. Oocysts
• B. Tachyzoites
• C. Bradyzoites
• D. Sporozoites

Answer: (A)

The main idea here is understanding Toxoplasma gondii's life cycle and which stage cats shed. Cats are the definitive hosts, and they release the parasite into the environment as oocysts in their feces. When first shed, these oocysts are unsporulated, and they must mature in the environment to become sporulated oocysts that contain sporozoites and are infectious. This is why contaminated soil or surfaces can spread infection to other animals and people.

Tachyzoites are the rapidly multiplying stage inside tissues during acute infection in any host. Bradyzoites are the slow-growing form found in tissue cysts during chronic infection. Sporozoites are the infectious units inside the sporulated oocyst, not a separate form shed directly from the cat.