Risk for toxoplasmic encephalitis in AIDS patients in Yugoslavia

Abstract

Objectives: To determine the incidence of toxoplasmic encephalitis (TE) in patients with acquired immunodeficiency syndrome (AIDS) in Yugoslavia and to analyze the contribution of sex, age, human immunodeficiency virus (HIV) transmission risk factors, CD4+ T-cell count, and systemic Pneumocystis carinii pneumonia (PCP) prophylaxis as risk factors for the development of TE. Design: Retrospective chart review of 288 (72%) of the 399 AIDS patients diagnosed in Yugoslavia during the 5-year period 1991 to 1995. Inclusion criteria included serology for toxoplasmosis performed prior to the TE episode. Results: Toxoplasma gondii-specific IgG antibodies were detected in 127 of the 288 AIDS patients (44.1%) tested serologically (including all with neurologic abnormalities). A total of 31 patients developed TE, indicating a TE overall attack rate of 7.8%. Of these, 29 TE episodes occurred in the T. gondii-seropositive patients (22.8%), significantly more often than in the T. gondii-seronegative (χ2 = 34.423, P < 0.005), among which TE occurred in two (2/161, 1.24%). By survival analysis, the cumulative incidence of TE in the T. gondii-seropositive patients was 32.7% for 60 months (30% for 24 months). Although not associated with age, sex, or HIV transmission risk factor, the risk for TE increased with the decrease in the CD4+ T-cell count (relative risk [RR] = 0.276, 95% confidence interval [Cl] = 0.198-0.673, P = 0.0013), and was reduced in patients on systemic PCP prophylaxis (RR = 0.222, 95% Cl = 0.068-0.642, P = 0.006). Conclusions: In areas of high exposure to T. gondii, such asYugoslavia, timely serology for toxoplasmosis in patients with AIDS and subsequent drug prophylaxis to prevent reactivation in seropositive patients is recommended.