T. cruzi OligoC-TesT: A Simplified and Standardized Polymerase Chain Reaction Format for Diagnosis of Chagas Disease

Abstract

BackgroundPCR has evolved into one of the most promising tools for T. cruzi detection in the diagnosis and control of Chagas disease. However, general use of the technique is hampered by its complexity and the lack of standardization.MethodologyWe here present the development and phase I evaluation of the T. cruzi OligoC-TesT, a simple and standardized dipstick format for detection of PCR amplified T. cruzi DNA. The specificity and sensitivity of the assay were evaluated on blood samples from 60 Chagas non-endemic and 48 endemic control persons and on biological samples from 33 patients, 7 reservoir animals, and 14 vectors collected in Chile.Principal FindingsThe lower detection limits of the T. cruzi OligoC-TesT were 1 pg and 1 to 10 fg of DNA from T. cruzi lineage I and II, respectively. The test showed a specificity of 100% (95% confidence interval [CI]: 96.6%–100%) on the control samples and a sensitivity of 93.9% (95% CI: 80.4%–98.3%), 100% (95% CI: 64.6%–100%), and 100% (95% CI: 78.5%–100%) on the human, rodent, and vector samples, respectively.ConclusionsThe T. cruzi OligoC-TesT showed high sensitivity and specificity on a diverse panel of biological samples. The new tool is an important step towards simplified and standardized molecular diagnosis of Chagas disease.

Chagas disease: Present status of pathogenic mechanisms and chemotherapy

“…cruzi antigens or its genomic material can be demonstrated in inflammatory foci from cardiac tissue during the chronic phases of the disease. This can be done through sensitive methods such as immunohistochemistry, polymerase chain reaction (PCR), and in situ hybridization (Britto, 2009;Deborggraeve et al, 2009;Duffy et al, 2009;Rassi et al, 2009a;Rassi and Rassi, 2009;Rassi et al, 2009c). Experimentally, this is demonstrated by attenuation of cardiomyopathy with parasite load reduction by trypanocidal treatment (Britto, 2009;Bustamante et al, 2008;Coura, 2009;Marin-Neto et al, 2009;Perez-Molina et al, 2009;Urbina, 2009b;Viotti et al, 2009).…”

Experiencia terapéutica en un centro para la enfermedad de Chagas

“…Sin embargo un método directo, como es la RCP Trypanosoma cruzi, se considera un indicador mucho más preciso de la presencia del parásito. Los niveles de sensibilidad pueden ser variables pero su especificidad es cercana a 100% 1,23 y nuevas técnicas tienen sensibilidad y especificidad casi 100% 24 . Por consenso, los criterios de curación más aceptados son la negativización de los exámenes parasitológicos directos, la RCP Trypanosoma cruzi no detectable (que también es un método directo), la disminución progresiva de los títulos serológicos y la remisión de las alteraciones electrocardiográ-ficas, todo lo que debe mantenerse en el tiempo.…”

Emerging and under-recognized Chagas cardiomyopathy in non-endemic countries

“…PCR for T. cruzi was not performed initially because serology is the gold-standard for diagnosis of chronic CD [26,27] , despite being affected by cross-reactions with antibodies induced by other parasites, namely Leishmania and T. rangeli [28] . Due to this, two different serologic tests were performed to confirm the results.…”