Neurologic manifestations of toxoplasmosis in AIDS.

Central nervous system (CNS) toxoplasmosis is the most common cause of cerebral mass lesions in AIDS patients. Toxoplasma gondii is commonly acquired through ingestion of contaminated meats resulting in latent infection. With the onset of immunosuppression, it may preferentially infect the CNS, resulting in a wide range of clinical presentations. Effective antibiotic therapy is available and capable of producing rapid remission of active infection but must be continued throughout life to prevent recurrence. Characteristic presentations and rapid therapeutic response permit presumptive diagnosis and initiation of specific antibiotics in many cases; however, appropriate clinical and radiographic monitoring to detect alternative or mixed pathologies is necessary. Unusual presentations may hinder rapid diagnosis and should be considered in AIDS patients with cryptic CNS symptoms. Despite increasing attention to primary prophylaxis, the worldwide distribution of this parasite, its potential to be the presenting illness in previously unidentified human immunodeficiency virus-infected individuals, and failures of prophylaxis are likely to make toxoplasmosis an important continuing source of neurologic morbidity in AIDS.