Chagas' disease or human American trypanosomiasis is caused by Trypanosoma cruzi, a parasite that is transmitted to humans by the faeces of blood-sucking triatomine bugs, by blood transfusion, and transplacentally. Chagas' disease has several successive phases: infection, acute, latent and chronic.

Diagnosis by PCR may be valuable regarding both its specificity and sensitivity. Use of PCR for detecting Trypanosoma cruzi infection in acute phase patients as well as in neonates was shown to be very sensitive. PCR was also shown to be the most useful tool for assessing parasitological cure after specific treatment. In case of chronic phase patients, parasitic load may be very low and the high sensitivity of PCR could be a valuable tool for assessing the parasitological status of the patient.