What are oocysts in relation to Toxoplasma?

Oocysts are the resistant and infectious form of Toxoplasma gondii that are shed in the feces of infected cats. This is significant because these oocysts can survive in the environment for long periods and are a primary means of transmission to other hosts, including humans. When humans or other animals ingest these oocysts, typically through contaminated water, soil, or food, they can develop an infection.

The other options describe different aspects or forms of the Toxoplasma organism but do not accurately define oocysts. The active form of Toxoplasma that causes symptoms is known as tachyzoites, while medications are used for treatment but are not oocysts themselves. Inactive spores in food do not represent the nature of Toxoplasma oocysts, which are specifically related to the fecal shedding by cats and have a significant role in the lifecycle and transmission of the parasite.