Chronic Chagas disease: presence of parasite DNA in the oesophagus of patients without megaoesophagus.

We have previously amplified Trypanosoma cruzi DNA by polymerase chain reaction (PCR) from the oesophagus of chagasic patients with megaoesophagus, whilst immunohistochemical analysis failed to detect T. cruzi antigen in the oesophagus of chagasic patients without megaoesophagus. During 2000-01, we tested for the presence of T. cruzi DNA in oesophageal tissue from 9 chronic chagasic patients without megaoesophagus and 5 were positive by PCR, which suggests that other factors, besides simply the presence of the parasite, should be considered in the understanding of the pathogenesis of megaoesophagus.