Cyst rupture as a pathogenic mechanism of toxoplasmic encephalitis.
Seemingly intact cysts and sequential stages of disintegrating cysts of Toxoplasma were identified immunohistologically within developing microglial nodules in a Panamanian night monkey (Aotus lemurinus). This monkey had been successfully immunized and challenged 5 months earlier. This supports the hypothesis that glial nodules unassociated with Toxoplasma tachyzoites may represent the tombstone of a Toxoplasma cyst. Disintegration of cysts may give rise to clinical encephalitis in the presence of apparently adequate immunity.
D000818:Animals; D001029:Aotus trivirgatus; D001921:Brain / Q000469:parasitology* / Q000473:pathology; D004660:Encephalitis / Q000209:etiology* / Q000469:parasitology / Q000473:pathology; D006968:Hypersensitivity, Delayed; D013116:Spinal Cord / Q000469:parasitology / Q000473:pathology; D014122:Toxoplasma / Q000166:cytology*; D014124:Toxoplasmosis, Animal / Q000276:immunology / Q000469:parasitology* / Q000473:pathology