Toxoplasmosis is a common parasitic infection. When contracted by a pregnant woman, toxoplasmosis can pose serious risks to the unborn baby. Simple precautions can reduce the chance of infection.

Pregnant women should avoid handling litter boxes and eating raw meat because the parasite may originate in cat feces or undercooked meat. If acquired during the first trimester of pregnancy, the infection can be devastating to an infant.

Toxoplasmosis affects the retina, the light-sensitive cells lining the back of the eye. Both eyes can be involved. If the infection settles in the macula, the area of the retina responsible for central vision, good vision can be lost forever.

When toxoplasmosis heals, it leaves a scar. The infection may recur years later, sometimes near the previously infected area. Swelling that fights the infection may cause floating spots, red, painful eyes, and poor vision.

Treating toxoplasmosis with oral medications can be very effective. Pyrimethamine and sulfa drugs are the classic choices for treatment with antibiotics, although some doctors add or substitute clindamycin. Occasionally, treatment with steroids, laser therapy, or cryotherapy (freezing) is prescribed.

Screening tests can identify women of childbearing age who are at risk of passing the infection to an unborn child.

(c) 2007 The American Academy of Ophthalmology