Toxoplasmosis is an acute or chronic, widespread disease of animals and humans caused by the obligate intracellular protozoon Toxoplasma gondii. Its definitive host is a cat or a felid. It makes use of other warm-blooded animals as intermediate hosts, including humans. Toxoplasmosis in adult humans is often asymptomatic or if symptoms are present, they are usually mild. However, if it occurs in pregnant women it may cause damage to the fetus (congenital toxoplasmosis). It may also lead to other forms of toxoplasmosis such as ocular toxoplasmosis. Ocular toxoplasmosis is characterized by an extensive connective tissue proliferation. The retina surrounding the lesions remains normal, and the ocular media remain clear. Chorioretinitis may be associated with all forms of toxoplasmosis, but is usually a late sequel of congenital toxoplasmosis. The severe ocular lesions in infants may lead to blindness. The most common symptom is a unilateral decrease in visual acuity in one eye. Ophthalmic examination reveals a focal, white retinitis and moderate inflammation of the vitreous humour. Treatment may be pyrimethamine, suladiazine, folinic acid, and occasionally, prednisone (for alleviating inflammation).
- toxoplasmic chorioretinitis
- toxoplasma chorioretinitis