Mem Inst Oswaldo Cruz, Rio de Janeiro, VOLUME 121 | 2026
Research Articles

Molecular characterisation of Trypanosoma cruzi in Triatoma dimidiata from a highland locality in western Panamá

Vanessa Jenny Pineda1, Kadir González1,2, José Eduardo Calzada1,3,+, Azael Saldaña4,+

1Instituto Conmemorativo Gorgas de Estudios de la Salud, Departamento de Investigaciones en Parasitología, Panamá, Panamá
2Universidad de Panamá, Facultad de Medicina, Departamento de Microbiología Humana, Panamá, Panamá
3Universidad de Panamá, Facultad de Medicina Veterinaria, Panamá, Panamá
4Universidad de Panamá, Facultad de Medicina, Centro de Investigación y Diagnóstico de Enfermedades Parasitarias, Panamá, Panamá

DOI: 10.1590/0074-02760250172
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ABSTRACT

BACKGROUND Triatoma dimidiata is a widely distributed vector of Trypanosoma cruzi in Mesoamerica, but its epidemiological role in most regions of Panamá remains poorly understood.
OBJECTIVES To investigate the presence, infection status, and feeding behaviour of T. dimidiata populations in peridomestic areas of Palmira Arriba, western Panamá.
METHODS Entomological surveys were conducted in five peridomestic sites of a rural highland community. Thirty-seven triatomines (13 adults and 24 nymphs) were collected from wooden piles and construction materials in contact with the ground. DNA from 30 specimens was analysed by polymerase chain reaction (PCR) for T. cruzi detection, genotyping [discrete typing unit (DTU) and haplotype identification], and blood meal source determination through cytochrome b amplification.
FINDINGS Twenty-one insects (70.0%) were positive for T. cruzi. Sixteen infections (76.2%) belonged to DTU I (TcI), including 13 TcIDOM and 14 TcIa genotypes, both linked to domestic and sylvatic cycles. Blood meal analysis revealed one mammalian and two avian feedings, indicating opportunistic behaviour.
MAIN CONCLUSIONS This study provides the first molecular confirmation of T. cruzi infection in T. dimidiata from Palmira Arriba. The combination of high infection prevalence, multiple developmental stages, and recent feeding suggests active local transmission favoured by humid and cool ecological conditions. Expanded surveillance and integrative One Health approaches are needed to elucidate transmission dynamics in highland rural Panamá.

key words: Trypanosoma cruzi discrete typing units Triatoma dimidiata molecular epidemiology Panama
REFERENCES
01. WHO - World Health Organization. Chagas disease (also known as American trypanosomiasis). 2023 [cited 2025 Mar 17]. Available from: https://www.who.int/news-room/fact-sheets/detail/ chagas-disease-(american-trypanosomiasis).
02. Rodriguez IG, Loaiza JR. American trypanosomiasis, or Chagas disease, in Panamá: a chronological synopsis of ecological and epidemiological research. Parasit Vectors. 2017; 10: 459.
03. Hurtado LA, Calzada JE, Pineda V, González K, Santamaría AM, Cáceres L, et al. Conocimientos y factores de riesgo relacionados con la enfermedad de Chagas en dos comunidades panameñas donde Rhodnius pallescens es el vector principal. Biomedica. 2014; 34: 260-70.
04. Saldaña A, Pineda V, Martinez I, Santamaria G, Santamaria AM, Miranda A, et al. A new endemic focus of Chagas disease in the northern region of Veraguas Province, Western Half Panamá, Central America. PLoS One. 2012; 7: e34657.
05. de Camargo MVT. Recolección y análisis de excretas de chinches Triatoma dimidiata, vector transmisor de la enfermedad de Chagas, en predios y alrededores de la Universidad Autónoma de Chiriquí y en el corregimiento de Palmira, distrito de Boquete. Plus Economía. 2020; 8: 47-56.
06. Gómez-Palacio A, Triana O, Jaramillo-O N, Dotson EM, Marcet PL. Eco-geographical differentiation among Colombian populations of the Chagas Disease vector Triatoma dimidiata (Hemiptera: Reduviidae). Infect Genet Evol. 2013; 20: 352-61.
07. Dorn PL, McClure AG, Gallaspy MD, Waleckx E, Woods AS, Monroy MC, et al. The diversity of the Chagas parasite, Trypanosoma cruzi, infecting the main Central American vector, Triatoma dimidiata, from México to Colombia. PLoS Negl Trop Dis. 2017; 11: e0005878.
08. Parra-Henao G, Angulo VM, Osorio L, Jaramillo-O N. Geographic distribution and ecology of Triatoma dimidiata (Hemiptera: Reduviidae) in Colombia. J Med Entomol. 2016; 53: 122-9.
09. Reyes-Novelo E, Ruiz-Piña H, Escobedo-Ortegón J, Barrera- Pérez M, Manrique-Saide P, Rodríguez-Vivas RI. Triatoma dimidiata (Latreille) abundance and infection with Trypanosoma cruzi in a rural community of Yucatan, México. Neotrop Entomol. 2013; 42: 317-24.
10. Chan-Espinoza D, Ruiz-Piña HA, Canché-Pool EB, Reyes-Novelo E. Spatial distribution of Triatoma dimidiata peridomestic colonies modulated by distance between susceptible microhabitat patches. Acta Trop. 2024; 253: 107169.
11. Murillo-Solano C, Ramos-Ligonio A, López-Monteon A, Guzmán-Gómez D, Torres-Montero J, Herrera C, et al. Diversity of Trypanosoma cruzi parasites infecting Triatoma dimidiata in Central Veracruz, México, and their One Health ecological interactions. Infect Genet Evol. 2021; 95: 105050.
12. Lima-Cordón RA, Stevens L, Solórzano Ortíz E, Rodas GA, Castellanos S, Rodas A, et al. Implementation science: epidemiology and feeding profiles of the Chagas vector Triatoma dimidiata prior to Ecohealth intervention for three locations in Central America. PLoS Negl Trop Dis. 2018; 12: e0006952.
13. Christensen HA, Sousa OE, De Vasquez AM. Host feeding profiles of Triatoma dimidiata in peridomestic habitats of western Panamá. Am J Trop Med Hyg. 1988; 38: 477-9.
14. National Geographic Institute “Tommy Guardia”. Official geographic data of the Republic of Panamá [Geospatial database]. 2023 [cited 2025 May]. Available from: https://ignPanamá.anati.gob.pa.
15. ETESA - Electric Transmission Company. Meteorological data from the Hydrometeorology Directorate of Panamá [Database]. Panamá City: Empresa de Transmisión Eléctrica S.A. 2023 [cited 2024 May]. Available from: https://www.hidromet.com.pa/.
16. INEC - National Institute of Statistics and Census. Agricultural statistics of the Republic of Panamá [Database]. Panamá City: Office of the Comptroller General of the Republic of Panamá. 2023 [cited 2025 May]. Available from: https://www.inec.gob.pa/.
17. MiAmbiente - Ministry of Environment. Forest cover and land use of the Republic of Panamá 2023. Panamá City: Ministerio de Ambiente. 2023 [cited 2023 May]. Available from: https://www. miambiente.gob.pa/.
18. Lent H, Wygodzinsky P. Revision of the Triatominae (Hemiptera:Reduviidae) and their significance as vectors of Chagas disease. Bull Am Mus Nat Hist. 1979; 163: 123-520.
19. Mendez E, Sousa OE. Identificación y distribución de los triatominos de Panamá (Hemíptera: Reduviidae: Triatominae). Rev Med Panamá. 1979; 4: 258-80.
20. Vallejo GA, Guhl F, Chiari E, MacEdo AM. Species specific detection of Trypanosoma cruzi and Trypanosoma rangeli in vector and mammalian hosts by polymerase chain reaction amplification of kinetoplast minicircle DNA. Acta Trop. 1999; 72: 203-12.
21. Muñoz-San Martín C, Apt W, Zulantay I. Real-time PCR strategy for the identification of Trypanosoma cruzi discrete typing units directly in chronically infected human blood. Infect Genet Evol. 2017; 49: 300-8.
22. Villa LM, Guhl F, Zabala D, Ramírez JD, Urrea DA, Hernández DC, et al. The identification of two Trypanosoma cruzi I genotypes from domestic and sylvatic transmission cycles in Colombia based on a single polymerase chain reaction amplification of the spliced-leader intergenic region. Mem Inst Oswaldo Cruz. 2013; 108(7): 932-5.
23. Falla A, Herrera C, Fajardo A, Montilla M, Vallejo GA, Guhl F. Haplotype identification within Trypanosoma cruzi I in Colombian isolates from several reservoirs, vectors and humans. Acta Trop. 2009; 110: 15-21.
24. Ngo KA, Kramer LD. Identification of mosquito bloodmeals using polymerase chain reaction (PCR) with order-specific primers. J Med Entomol. 2003; 40: 215-22.
25. Moo-Millan JI, Arnal A, Pérez-Carrillo S, Hernandez-Andrade A, Ramírez-Sierra MJ, Rosado-Vallado M, et al. Disentangling Trypanosoma cruzi transmission cycle dynamics through the identification of blood meal sources of natural populations of Triatoma dimidiata in Yucatán, México. Parasit Vectors. 2019; 12: 572.
26. Caranci AT, Grieco JP, Achee NL, Hoel DF, Bautista K, King R, et al. Distribution of Triatoma dimidiata sensu lato (Reduviidae: Triatominae) and risk factors associated with household invasion in northern Belize, Central America. J Med Entomol. 2022; 59: 764-71.
27. Velásquez-Ortiz N, Hernández C, Cantillo-Barraza O, Medina M, Medina-Alfonso M, Suescún-Carrero S, et al. Estimating the genetic structure of Triatoma dimidiata (Hemiptera: Reduviidae) and the transmission dynamics of Trypanosoma cruzi in Boyacá, eastern Colombia. PLoS Negl Trop Dis. 2022; 16: e0010534.
28. Cantillo-Barraza O, Medina M, Zuluaga S, Valverde C, Motta C, Ladino A, et al. Eco-epidemiological study reveals the importance of Triatoma dimidiata in the Trypanosoma cruzi transmission, in a municipality certified without transmission by Rhodnius prolixus in Colombia. Acta Trop. 2020; 209: 105550.
29. Calzada JE, Samudio F, de Juncá C, Pineda V, Burleigh BA, Saldaña A. Genetic diversity of Trypanosoma cruzi in Panamá inferred by multi-locus sequence typing of mitochondrial genes. Microorganisms. 2022; 10: 287.
30. Gómez-Hernández C, Pérez SD, Rezende-Oliveira K, Barbosa CG, Lages-Silva E, Ramírez LE, et al. Evaluation of the multispecies coalescent method to explore intra-Trypanosoma cruzi I relationships and genetic diversity. Parasitology. 2019; 146: 1063-74.
31. Cantillo-Barraza O, Medina M, Zuluaga S, Blanco MI, Caro R, Jaimes-Dueñez J, et al. Distribution and natural infection status of synantrophic triatomines (Hemiptera: Reduviidae), vectors of Trypanosoma cruzi, reveals new epidemiological scenarios for chagas disease in the highlands of Colombia. PLoS Negl Trop Dis. 202; 15: e0009574.
32. Koyoc-Cardeña E, Medina-Barreiro A, Escobedo-Ortegón FJ, Rodríguez-Buenfil JC, Barrera-Pérez M, Reyes-Novelo E, et al. Chicken coops, Triatoma dimidiata infestation and its infection with Trypanosoma cruzi in a rural village of Yucatan, México. Rev Inst Med Trop São Paulo. 2015; 57: 269-72.
33. Moo-Millan JI, Hernández-Andrade A, May-Concha IJ, Montalvo- Balam TJ, Arnal A, Talavera-Escalante MJ, et al. Temporal variation of Triatoma dimidiata abundance and infection with Trypanosoma cruzi in domestic and sylvatic habitats of rural Yucatan, México. Acta Trop. 2023; 248: 107038.
34. Case BKM, Young JG, Penados D, Monroy C, Hébert-Dufresne L, Stevens L. Spatial epidemiology and adaptive targeted sampling to manage the Chagas disease vector Triatoma dimidiata. PLoS Negl Trop Dis. 2022; 16: e0010436.
35. Sousa OE, Samudio F, De Juncá C, Calzada JE. Molecular characterization of human Trypanosoma cruzi isolates from endemic areas in Panamá. Mem Inst Oswaldo Cruz. 2006; 101(4): 455-7.
36. Samudio F, Ortega-Barría E, Saldaña A, Calzada J. Predominance of Trypanosoma cruzi I among Panamánian sylvatic isolates. Acta Trop. 2007; 101: 178-81.
37. Prescilla-Ledezma AP, Blandon R, Schijman AG, Benatar A, Saldaña A, Osuna A. Mixed infections by different Trypanosoma cruzi discrete typing units among Chagas disease patients in an endemic community in Panamá. PLoS One. 2021; 16: e0250184.
38. Díaz-Valdez J, Martínez I, Rodríguez-Moreno Á, Gutierrez-Granados G, Leon-Villegas RI, Sanchez-Cordero V, et al. Multiple discrete typing units of Trypanosoma cruzi infect sylvatic Triatoma dimidiata and Panstrongylus rufotuberculatus in southeast México. Am J Trop Med Hyg. 2021; 105: 1042-9.
39. Polonio R, López-Domínguez J, Herrera C, Dumonteil E. Molecular ecology of Triatoma dimidiata in southern Belize reveals risk for human infection and the local differentiation of Trypanosoma cruzi parasites. Int J Infect Dis. 2021; 108: 320-9.
40. De Fuentes-Vicente JA, Cabrera-Bravo M, Enríquez-Vara JN, Bucio-Torres MI, Gutiérrez-Cabrera AE, Vidal-López DG, et al. Relationships between altitude, triatomine (Triatoma dimidiata) immune response and virulence of Trypanosoma cruzi, the causal agent of Chagas’ disease. Med Vet Entomol. 2017; 31: 63-71.
41. Nogueda-Torres B, Montañez-Valdez OD, Michel-Parra JG, Martínez- Grant DM, Martínez-Ibarra JA. Biological parameters of three populations of Triatoma dimidiata s. s. (hemiptera: Reduviidae) from western México. J Med Entomol. 2021; 58: 2114-23.
42. Monroy MC, Penados D, Pineda J, Ruiz EL, Agreda EO, Alcantara B, et al. A multidisciplinary, collaborative, inter-agency and comprehensive approach for the control of Chagas disease as a public health problem in Guatemala. Acta Trop. 2022; 225: 106157.

Financial support: This study was carried out with funding from the Ministry of Economy and Finance (MEF) of the Republic of Panamá, Project No. 0420. Additional support was provided by the National Research System (SNI) of Panamá through research incentives awarded to AS, KG and JEC as members of SNI-SENACYT Panamá.
VJP and KG contributed equally to this work.
+ Corresponding authors: jecalzada@gorgas.gob.pa | ORCID https://orcid.org/0000-0002-6669-4290 / azael.saldana@up.ac.pa | ORCID https://orcid.org/0000-0002-5653-1332
Received 10 July 2025
Accepted 30 October 2025

HOW TO CITE
Pineda VJ, González K, Calzada JE, Saldaña A. Molecular characterisation of Trypanosoma cruzi in Triatoma dimidiata from a highland locality in western Panamá. Mem Inst Oswaldo Cruz. 2025; 120: e250172.

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