Toxoplasma gondii is a parasite carried by cats that can be transmitted to humans. While it has no effect on most people, it can cause symptoms in people with weak immune systems. Because toxoplasmosis is especially hazardous to unborn babies, health officials recommend that pregnant women avoid cleaning litter boxes, if at all possible.
Thankfully there are ways to protect yourself without having to give up your feline friend. Recommendations include: keep your cat indoors; always cover its litter box when not in use; change the cat’s litter daily (T. gondii does not become infectious until 1 to 5 days after it is shed in feces); avoid feeding cats raw or undercooked meat; wash your hands after gardening; and wash fruits and vegetables from the garden.
Interestingly, toxoplasmosis has recently been shown to make mice and other animals unafraid of cats: it makes the scent of cats attractive!
There are have been several reports that linked Toxoplasmosis to mental illness. Read the CBS news article here.