Detection of Trypanosoma cruzi and Trypanosoma rangeli Infection by Duplex PCR Assay Based on Telomeric Sequences

We used the species specificity and repetitious nature of subtelomeric kinetoplastida sequences to generate a duplex PCR assay for the simultaneous detection of Trypanosoma cruzi and Trypanosoma rangeli in experi-mentally and naturally infected triatomine (Reduviid) bugs and in infected human subjects. The assay was species specific and was capable of detecting 1/20th of T. cruzi and 1/4th of T. rangeli cell equivalents without complementary hybridization. In addition, the PCR-based assay was robust enough for direct application to difficult biological samples such as Reduviid feces or guts and was capable of recognizing all T. cruzi and T. rangeli strains and lineages. Because the assay primers amplify entirely different target sequences, no reaction interference was observed, facilitating future adaptation of this assay to an automated format. Trypanosoma cruzi causes Chagas ’ disease, a fatal illness endemic to many Latin American countries. T. cruzi shares reservoirs and vectors with the related protozoan Trypanosoma rangeli, which is pathogenic to Reduviid bugs but apparently harmless to humans (1). These parasites share morphological similarities and antigenic determinants, making microscopic and serological diagnosis a challenge (13, 27). In recent years