Diagnostico molecular de doença de Chagas em pacientes soronegativos portadores de megaesofago

Abstract

Background: After 100 years of research, Chagas disease (CD) remains an important public health problem in Latin America. Symptomatic chronic phase is usually characterized by cardiac or digestive commitment and its current diagnosis relies on the measurement of T. cruzi-specific antibodies produced in response to the infection.However, detection of parasite DNA in seronegative persons has been reported.Objectives: Prevalence of CD in a population with esophageal disorders was assessed by conventional serology. We also detected T. cruzi DNA in blood samples of seronegative and inconclusive patients by N-PCR (nested-PCR).Methods and Results: A seroprevalence of 79% for CD in 512 patients with esophageal disorders was determined by ELISA and IIF. Out of 41 blood samples, N-PCR was positive in 31 (76%) cases when serology was negative or inconclusive.Conclusion: As all patients presented suggestive clinical signs of digestive form of CD and most of them were born in endemic areas, we highlight the importance of diagnosis improvement and its implication in blood banks screening. Our data suggest that N-PCR seems to be effective for detection of T. cruzi DNA in patients with inconclusive or negative serology and, eventually, it may be useful to clarify megaesophagus etiology.