Molecular methods have been developed for the detection and quantification of Trypanosoma cruzi DNA in blood samples from patients with Chagas disease. However, aspects of sample processing necessary for quantitative real-time PCR (qPCR), such as the addition of guanidine hydrochloride to whole blood samples, may limit timely access to molecular diagnosis. We analysed 169 samples from serum and guanidine-EDTA blood (GEB) obtained from patients in acute and chronic phases of Chagas disease. We applied qPCR targeted to the satellite DNA region. Finally, we compared the parasite loads and cycle of threshold values of the qPCR. The results confirmed the usefulness of serum samples for the detection and quantification of parasite DNA in patients with Chagas disease, especially in the acute phase. However, the parasite loads detected in serum samples from patients in the chronic phase were lower than those detected in GEB samples. The epidemiological implications of the findings are herein discussed.
Keywords: qPCR_Ct_GEB threshold cycle of qPCR for Trypanosoma cruzi in GEB samples; qPCR_Ct_Serum threshold cycle of qPCR for T. cruzi in serum samples; qPCR_GEB parasite load in GEB samples; qPCR_IAC_GEB threshold cycle for IAC in GEB samples; qPCR_IAC_Serum threshold cycle for IAC in GEB samples; qPCR_Serum parasite load in serum samples; DNA; Trypanosoma cruzi; qPCR; satellite DNA.