PCR-based diagnosis for Chagas' disease in Bolivian children living in an active transmission area: comparison with conventional serological and parasitological diagnosis

Abstract

A large field study has been performed in the Cochabamba region of Bolivia with the aim of comparing the polymerase chain reaction (PCR) with other diagnosis methods for Chagas' disease. The amplification of Trypanosoma cruzì-specific kinetoplast DNA sequences in blood samples was compared with classical serological methods, specific IgM detection and direct parasite visualization for 268 school children in a single village where Chagas' disease transmission is active. cardiac and/or digestive manifestations, the latter with pathological dilatation of the colon andor esophagus optical and electronic microscopy show the presence of inflammatory infiltrates, with degeneration of m hand, examination of esophageal tissues of Chagas' disease patients with the digestive clinical form have hithe to demonstrate a close correlation between the megaesophagus pathology and the presence of Z cruzi.. We have

Assessment of chemiluminescence and PCR effectiveness in relation to conventional serological tests for the diagnosis of Chagas' disease

“…Some authors have found low sensitivity through the hot-start technique with positive results below 60% 3 7 . It has already been demonstrated that PCR is not appropriate as the sole diagnosis method, rather as a complement to serology, particularly in the case of indeterminate patients 17 .The results obtained in this study show that the three traditional serological reactions are still sufficiently effective for the diagnosis of Chagas' disease. This is due to the fact that, up to now, no other methodology has been standardized with higher rates than those found for these methods, i.e.…”

“…Some authors have found low sensitivity through the hot-start technique with positive results below 60% 3 7 . It has already been demonstrated that PCR is not appropriate as the sole diagnosis method, rather as a complement to serology, particularly in the case of indeterminate patients 17 .…”

Early, intermediate, and late acute stages in Chagas' disease: a study combining anti-galactose IgG, specific serodiagnosis, and polymerase chain reaction analysis.

“…Our results also confirm the high sensitivity of the PCR method. 4,17 Anti-Gal␣ 1,3 Gal IgG detected eight infected cases in which specific serology had failed. This suggests a very early acute T. cruzi infection, when specific anti-T. cruzi antibodies are not yet present.…”

“…Polymerase chain reaction assays for the detection of T. cruzi DNA have been recently described, and are considered the most sensitive methods to detect T. cruzi in chagasic patients. 4,16,17 In endemic countries, children are exposed to T. cruzi early in life. However, the detection of the early chagasic infection is difficult due to ancient and subjective methods currently available.…”

Chagas' heart disease

“…Similar results were obtained by detection of T. cruzi genomic fragments applying the polymerase chain reaction method 116 . In addition, molecular biology techniques now permit the detection of circulating T. cruzi antigens in a much larger contingent of chagasic patients in whom the conventional serologic methods fail for such purpose 117,118 . It is plausible to speculate that even low-grade persistent parasitism may lead to a continuous antigenic feedback loop to the autoimmune system, which may constitute the main damaging mechanism in the late phase [119][120][121] .…”