In an AIDS patient chorioretinitis is typically caused by:

Cytomegalovirus It may cause disseminated disease, although, more commonly, it affects the eye and gastrointestinal tract. Chorioretinitis was seen in approximately 25% of patients before the advent of HAA, but this has decreased dramatically after the initiation of HAA. Cytomegalovirus retinitis occurs almost exclusively in patients with CD4+ T cell counts less than 50 per microliter. Cryptococcosis Meningitis is the major clinical manifestation of cryptococcosis Toxoplasma gondii It causes encephalitis and is responsible for 50% of all mass lesions in the central nervous system.