<prompt> Chorioretinitis is caused by -ToxoplasmosisCMVRubellaOncocerca volvulus  <response>: Toxoplasmosis is known to produce necrotising chorioretinitis. Systemic toxoplasmosis occurs in humans in two forms: congenital and acquired. 1. Congenital toxoplasmosis:The characteristic triad of congenital toxoplasmosis includes: convulsions, chorio-retinitis and intracranial calcification. 2. Acquired toxoplasmosis:Most of the patients are subclinical asymptomatic; and the typical chorioretinal lesion similar to congenital toxoplasmosis is discovered by chance. 