[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Microbiology](https://durgical.com/en/microbiology/) › [Other parasites of interest](https://durgical.com/en/microbiology/groups/other-parasites-of-interest/) › Trypanosoma rangeli [Microbiology](https://durgical.com/en/microbiology/) · [Other parasites of interest](https://durgical.com/en/microbiology/groups/other-parasites-of-interest/) # Trypanosoma rangeli - Parasite - For completeness A trypanosome that infects people without making them ill. It shares vectors with the Chagas parasite in Colombia and can confuse diagnosis. Updated 2026-11-01 ## Key points - Non-pathogenic for humans, but confused with T. cruzi. - Transmitted by saliva (bite), not by faeces like T. cruzi. - Small subterminal kinetoplast; longer trypomastigote. - Cross-reacts in serology and kinetoplast PCR: a cause of false-positive Chagas results. ## At a glance **Shape** Long slender trypomastigote with a well-developed undulating membrane **Type** Flagellate protozoan (kinetoplastid), haemoflagellate **Stain** Giemsa: small subterminal kinetoplast (in T. cruzi it is large and nearly terminal) **Size** Blood trypomastigote longer than that of T. cruzi ## Morphology - Long trypomastigote with a small kinetoplast set back from the posterior end: the key to separating it from T. cruzi on a smear. - No intracellular amastigotes have been found in vertebrates, unlike T. cruzi. - In the insect it passes through epimastigotes in the gut and haemolymph before invading the salivary glands. ## Transmission - Mainly by the bite (saliva) of triatomine bugs of the genus Rhodnius, such as R. prolixus. - The faecal route is secondary, the reverse of T. cruzi. **Reservoir:** Wild and domestic mammals of Chagas areas; Humans (infection without disease) **Vector:** Triatomine bugs of the genus Rhodnius, mainly R. prolixus (also R. colombiensis and R. pallescens). ### Isolation precautions What the care team adds to standard precautions. - Standard ## Life cycle - The triatomine swallows trypomastigotes while feeding on an infected mammal. - In the midgut it turns into an epimastigote and multiplies. - It crosses the gut wall and multiplies in the insect's haemolymph. - It invades the salivary glands and becomes an infective metacyclic trypomastigote. - With the bite it passes in saliva to the mammal and circulates in blood without harming organs. ## Virulence factors - No harm is known in humans or other vertebrates; immunity controls the infection. ## Diseases it causes - Asymptomatic human infection; it matters because it mimics T. cruzi on smears, xenodiagnosis, serology and some PCRs ## Diagnosis - Giemsa blood smear or thick film: a longer trypomastigote with a small subterminal kinetoplast. - Xenodiagnosis and blood culture: forms appear in the insect or culture that must be told apart from T. cruzi. - Serology: it shares antigens with T. cruzi and can cross-react. - Species-discriminating PCR (e.g. histone H2A or sno-RNA genes); kinetoplast-DNA PCRs can react with T. rangeli. ## Treatment No treatment is needed: it causes no disease. What matters is not mistaking it for T. cruzi and not treating a Chagas infection that is not there. Drug class only; doses and regimens are set by the clinician from the current guideline. ## Prevention - The same triatomine control that prevents Chagas: better housing and indoor spraying. ## In Colombia Colombia is one of the countries where T. rangeli shares vectors, reservoirs and areas with T. cruzi; the first human case was described here (1949). Mixed infections with both trypanosomes have been found in Rhodnius colombiensis from Coyaima (Tolima). That is why blood banks and labs confirm reactive results with tests that separate the two species. ## Memory aid Rangeli kisses with saliva, cruzi soils with faeces: the first enters through the bite and does no harm. ## Test yourself Think of the answer, then tap the question to see it. ## Why does Trypanosoma rangeli matter if it causes no disease? It shares vectors and areas with T. cruzi and can give false-positive Chagas results on smears, serology or some PCRs. ## Which morphological feature separates it from T. cruzi on a smear? Its kinetoplast is small and subterminal and the trypomastigote is longer; T. cruzi has a large, nearly terminal kinetoplast. ## By which route does T. rangeli reach humans? Mainly through the triatomine's saliva during the bite, because the parasite reaches the insect's salivary glands. [Add to my cards (3)](https://durgical.app/estudiar/?add=/en/microbiology/trypanosoma-rangeli/) ## Related - [Trypanosoma cruzi](https://durgical.com/en/microbiology/trypanosoma-cruzi/) - [Trypanosoma brucei gambiense and T. b. rhodesiense](https://durgical.com/en/microbiology/trypanosoma-brucei-gambiense-and-t-b-rhodesiense/) - [Triatomines (Rhodnius prolixus, Triatoma dimidiata)](https://durgical.com/en/microbiology/triatomines/) ## What the colours mean **Gram-positive** Thick peptidoglycan wall: stains purple. **Gram-negative** Thin wall with an outer membrane: stains pink. **Acid-fast** Lipid-rich wall (mycobacteria): Ziehl–Neelsen stain. [← Back to the group: Other parasites of interest](https://durgical.com/en/microbiology/groups/other-parasites-of-interest/) Educational content on microorganisms; not a treatment guide and no substitute for a health professional's advice. No doses are given. Sources: [Detection of Trypanosoma cruzi and Trypanosoma rangeli infection in triatomine vectors by amplification of the histone H2A/SIRE and the sno-RNA-C11 genes](https://www.scielo.br/j/rimtsp/a/NKs6mMswrcYwvr9Q7g6z48N/abstract/?lang=en) (Revista do Instituto de Medicina Tropical de São Paulo, 2007); Parasitosis humanas (Botero y Restrepo), 5.ª ed. (Corporación para Investigaciones Biológicas (CIB), 2012). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/microbiology/trypanosoma-rangeli/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/microbiology/trypanosoma-rangeli/