[Severe disseminated toxoplasmosis with atypical chorioretinitis. A case of primary infection].

The clinical diagnosis of ocular toxoplasmosis is based on clinical features and biological tests: polymerase chain reaction (PCR) and the determination of intraocular specific antibody secretion (Goldmann-Witmer coefficient) on aqueous humor. Older patients may have a higher prevalence of ocular involvement and more severe ocular disease during the acute phase of recently acquired systemic infection because of altered cell-mediated immunity. Moreover, the genotype of the infecting parasite (particularly involving neotropical Type I Toxoplasma gondii strain), appears to be an important determinant of disease severity.