Toxoplasmosis of the central nervous system in the acquired immunodeficiency syndrome.

Acute encephalitis caused by Toxoplasma gondi was diagnosed at autopsy in 10 (20.4%) of the 49 patients. All patients had under lying immunodeficiency due to AIDS and showed selective involvement of central nervous system at autopsy. Sexual promiscuity was the risk factor in nine cases while one case had a history of blood transfusion. Diagnosis of toxoplasmosis was hampered by a lack of suspicion that Toxoplasma could be the agent causing necrotising encephalitis. The large number of cases of CNS toxoplasmosis appearing in AIDs patients emphasize the necessity of including toxoplasmosis in the differential diagnosis of encephalitis of unknown aetiology.