Xenodiagnosis is a diagnostic method used to document the presence of infectious disease microorganisms or pathogens by exposing possibly infected tissue to a vector and then examining the vector for the presence of the microorganisms or pathogens it may have ingested.
[1][2] Xenodiagnosis has not been commonly used in diagnosing Lyme disease because in vitro cell culturing now serves the purpose,[3] however the process is commonly used to diagnose infections involving microorganisms such as trypanosomiasis.
Medical professionals primarily use xenodiagnosis in determining the presence of a chronic infection of Trypanosoma cruzi (the flagellate that causes Chagas disease).
Directly and definitively demonstrating the presence of this causative agent in a patient proves difficult.
Therefore, the doctor allows a triatominae, a vector of the flagellate, to take a blood meal from the patient.