Trypanosoma rangeli

Trypanosoma rangeli is an American trypanosomiasis that is considered nonpathogenic.

Disease / Pathology

Trypanosoma rangeli does not cause persistent infection and therefore considered nonpathogenic to humans, It is a pathogens to insects as is Trypanosoma cruzi. However it does not cause Chaga’s disease as does Trypanosoma cruzi.

Location of the Host

Trypanosoma rangeli is located in the peripheral blood and must be distinguished from other pathogenic Trypanosomes such as Trypanosome cruzi which is found in the same geographical area. The presence/detection of Trypanosoma rangeli in humans is often misdiagnosed as the pathogenic Trypanosoma cruzi.

Geographic Distribution

Trypanosoma rangeli is found in subtropical and tropical areas of the Americas.

Life Cycle

The Trypanosoma rangeli lifecycle is similar to that of T. cruzi in that it is transmitted via the Triatomid bug. However, as stated previously it is not pathogenic and is considered a benign infection.

Morphology & Diagnosis

Trypanosoma rangeli must be distinguished from Trypanosoma cruzi which is endemic in the same geographical area.

The kinetoplast morphology is the most likely choice for differentiating the two as the kinetoplast is substantially larger in Trypanosoma cruzi. Trypanosoma rangeli is also more slender in form with an undulating membrane that may or not be present.

The differentiation can also be made based on the travel history being limited to the Americas along with the morphology. Any travel history to Africa will then complicate the differentiation and will have to include PCR or other special testing as well as clinical symptoms. Both Trypanosoma rangeli and Trypanosoma cruzi share similar surface antigens and therefore surface antigens based testing cannot reliably differentiate the two.

Mixed infections have been seen so it is important to thoroughly examine a smear for consistent morphologic forms.


Trypanosome rangeli – note the pointy end, undulating membrane, and the lack of a prominent kinetoplast