What is the primary route of Toxoplasma gondii transmission to humans?

The primary route of Toxoplasma gondii transmission to humans is through cats. Cats are the definitive hosts of the parasite, meaning that it can complete its life cycle within them. When cats shed oocysts in their feces, these oocysts can contaminate soil, water, and food sources. Humans can be exposed to Toxoplasma gondii primarily through handling cat litter or soil that has been contaminated with feces containing these oocysts.

While cats are the main source of transmission, it is important to note that other routes of transmission exist, such as the consumption of contaminated undercooked meat, particularly pork, or exposure to contaminated soil. However, these are considered secondary routes compared to the significant role of cats in the lifecycle of Toxoplasma gondii and the frequency with which humans can interact with contaminated feline waste. Additionally, insects do not play a role in the transmission of this parasite, making them an irrelevant option in this context.