Persistent toxoplasma bradyzoite cysts in the brain: incidental finding in an immunocompetent patient without evidence of a toxoplasmosis.

We report on a 72-year-old patient in whom autopsy demonstrated incidentally intracerebral Toxoplasma gondii cysts, locally restricted in the occipital lobe, in association with only a few CD4+ and CD8+ T cells and a mild microglial activation. The patient was HIV-negative. Serologically, there was no evidence for an active inflammation (Toxoplasma gondii specific antibody IgG-positive, IgM-negative). This unusual observation may indicate that in patients with sepsis, who may yield to a state of immunodysbalance, a focal reactivation of parasites may ensue in the absence of conditions predisposing for opportunistic infection.