A parasitic infection can give you schizophrenia, make you have a car crash, or determine the sex of your child.
published online March 1, 2007
Five years ago, Oxford University zoologists showed that the parasite Toxoplasma gondii alters the brain chemistry of rats so that they are more likely to seek out cats. Infection thus makes a rat more likely to be killed and the parasite more likely to end up in a cat—the only host in which it can complete the reproductive step of its life cycle. The parasite also lives in the brain cells of thousands of species, including about 60 million supposedly symptom-free Americans. Studies over the past few years have suggested that toxoplasmosis infections in humans, too, may cause behavioral changes—from subtle shifts to outright schizophrenia. Two studies this year add even weirder twists.
Toxoplasma gondii, revealed here in