Molecular detection of Trypanosoma cruzi from formalin fixed placentas and fetuses of Wistar rats

Chagas disease is a tropical disease, endemic of the Americas and caused by the protozoan Trypanosoma cruzi. The classic transmission route of T. cruzi is based on the contact with feces from Triatominae insects containing trypomastigotes forms of the parasite. T. cruzi is also spread by oral and congenital forms, besides blood donation and organ transplant transmission. The parasite has a tropism to several organs and tissues, including heart, brain, digestive tract, muscles, placenta, and fetuses. The determination of parasite burden in organs is an important parameter for scientific assays related to parasite control and epidemiology. Among the procedures to detect and quantify T. cruzi, PCR demonstrates high sensitivity and specificity. In this study, we developed a simple and fast method to detect T. cruzi from fixed placentas and fetuses of Wistar rats. T. cruzi was detected only in tissues from infected animals, with different parasite burdens. Once the histology usually demonstrates some limitations such as low sensitivity and specificity to detect T. cruzi in fetuses, our methodology will be useful for fixed fetal tissues from organ banks. The detection of T. cruzi from gestational tissues will contribute to the elucidation of mechanisms related to congenital Chagas disease.