Infection from undercooked meat typically involves tissue cysts containing which stage of Toxoplasma gondii?

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

Answer: (A)

In toxoplasmosis, tissue cysts in meat contain the bradyzoite stage. These bradyzoites persist in muscle and brain of intermediate hosts and survive cooking unless the meat is heated thoroughly. When the meat is consumed, bradyzoites convert to tachyzoites in the new host and begin rapid replication, causing infection. The other forms serve different roles: tachyzoites are the actively multiplying cells during acute infection; oocysts are produced in the cat’s intestine and shed in feces, becoming environmentally resistant; sporozoites are the infectious units inside sporulated oocysts. So the meat-borne infection specifically involves bradyzoites within tissue cysts.