Toxoplasma Gondii: The Cat-Transmitted Parasite That Has Infected Billions Worldwide

One of the world's most effective parasites doesn't spread through mosquito bites or undercooked snails — but through the common house cat.

Called toxoplasma gondii, the parasite is a single-cell organism that primarily spreads to humans via cat turds, but also through raw or undercooked meat, contaminated water, and from a mother to her fetus.

Its symptoms range from mild aches and pains to debilitating neural impairment, which makes it all the more horrific.