Cerebral toxoplasmosis in Danish AIDS patients

We estimate the frequency of central nervous system (CNS) toxoplasmosis in Danish AIDS patients and evaluate the diagnostic accuracy using the following criteria for acceptance of the diagnosis: either (1) the demonstration of Toxoplasma gondii in brain tissue or (2) one or more hypodense or ring-enhancing lesions on computerized axial tomography (CAT) scan and a neurologic and CAT scan improvement in response to 2 weeks of treatment. From 1981 until July 1990 266 patients were diagnosed with AIDS at Hvidovre Hospital, Copenhagen and 29 (11%) were treated, suspected for CNS toxoplasmosis. 17 patients had the diagnosis confirmed but since 5 patients, who were never treated, were diagnosed at autopsy, the overall cumulated incidence was 8% (22/266 patients). The overall diagnostic accuracy was 59% (17/29 patients) showing some changes over time. Among patients diagnosed with AIDS in 1988 or later, the accuracy was 83% (10/12 patients) while among patients diagnosed in 1987 or earlier the accuracy was 41% (7/17 patients). Four patients were diagnosed with Pneumocystis carinii pneumonia (PCP) prior to the diagnosis of CNS toxoplasmosis, while among patients with toxoplasmosis as the AIDS-defining diagnosis, 3 later developed PCP. None of these 7 patients had received secondary prophylaxis with a drug containing sulfonamide.