HIV and Chagas Disease: An Evaluation of the Use of Real-Time Quantitative Polymerase Chain Reaction to Measure Levels of Trypanosoma cruzi Parasitemia in HIV Patients in Cochabamba, Bolivia

Abstract

ABSTRACT. This cross-sectional study evaluated epidemiologic characteristics of persons living with HIV (PWH) coinfected with Trypanosoma cruzi in Cochabamba, Bolivia, and estimated T. cruzi parasitemia by real-time quantitative polymerase chain reaction (qPCR) in patients with and without evidence of reactivation by direct microscopy. Thirty-two of the 116 HIV patients evaluated had positive serology for T. cruzi indicative of chronic Chagas disease (27.6%). Sixteen of the 32 (50%) patients with positive serology were positive by quantitative polymerase chain reaction (qPCR), and four of the 32 (12.5%) were positive by direct microscopy. The median parasite load by qPCR in those with CD4+ < 200 was 168 parasites/mL (73-9951) compared with 28.5 parasites/mL (15–1,528) in those with CD4+ ≥ 200 (P = 0.89). There was a significant inverse relationship between the degree of parasitemia estimated by qPCR from blood clot and CD4+ count on the logarithmic scale (rsBC= –0.70, P = 0.007). The correlation between T. cruzi estimated by qPCR+ blood clot and HIV viral load was statistically significant with rsBC = 0.61, P = 0.047. Given the significant mortality of PWH and Chagas reactivation and that 57% of our patients with CD4+ counts < 200 cells/mm3 showed evidence of reactivation, we propose that screening for chronic Chagas disease be considered in PWH in regions endemic for Chagas disease and in the immigrant populations in nonendemic regions. Additionally, our study showed that PWH with advancing immunosuppression have higher levels of estimated parasitemia measured by qPCR and suggests a role for active surveillance for Chagas reactivation with consideration of treatment with antitrypanosomal therapy until immune reconstitution can be achieved.