Q: Central nervous system (CNS) toxoplasmosis is more common than extracerebral toxoplasmosis?
Immuno-compromise state is the biggest risk factor for clinical toxoplasmosis. Interestingly, CNS is the most affected system. Solo extracerebral toxoplasmosis is rare. Toxoplasmosis in lungs, eyes, or as disseminated infection usually occur along with CNS infection.
Another important pearl for clinicians to remember is that fever may not be present in toxoplasmic encephalitis due to immunosuppression. Headache is the most prominent symptom with mental status change or seizure.
Multiple ring-enhancing lesions on brain imaging is considered a hallmark for the diagnosis.
References:1. Belanger F, Derouin F, Grangeot-Keros L, Meyer L. Incidence and risk factors of toxoplasmosis in a cohort of human immunodeficiency virus-infected patients: 1988-1995. HEMOCO and SEROCO Study Groups. Clin Infect Dis 1999; 28:575.