Estimation of Trypanosoma cruzi infection in the main vector Triatoma infestans: accounting for imperfect detection using site-occupancy models.

Publisher: BioMed Central Country of Publication: England NLM ID: 101462774 Publication Model: Electronic Cited Medium: Internet ISSN: 1756-3305 (Electronic) Linking ISSN: 17563305 NLM ISO Abbreviation: Parasit Vectors Subsets: MEDLINE

Original Publication: London : BioMed Central

Triatoma*/parasitology ; Trypanosoma cruzi*/genetics ; Trypanosoma cruzi*/isolation & purification ; Insect Vectors*/parasitology ; Chagas Disease*/transmission ; Chagas Disease*/parasitology ; Chagas Disease*/diagnosis ; Chagas Disease*/epidemiology ; Polymerase Chain Reaction*/methods; Animals ; Microscopy/methods ; DNA, Protozoan/genetics

Background: Vector infection prevalence is a key component of vectorial capacity and transmission risk. Optical microscopy observation (OM) of fecal drops has been the classic method for detecting Trypanosoma cruzi infection in triatomine bugs until the advent of polymerase chain reaction (PCR)-based techniques. However, agreement among OM- and PCR-based techniques has been highly heterogeneous.
Methods: We used hierarchical site-occupancy models accounting for imperfect detection to estimate method-specific detection probabilities of T. cruzi infection in field-collected Triatoma infestans and to assess whether T. cruzi infection varied with triatomine developmental stage and collection ecotope. We also performed a scoping review of the literature on comparisons between OM and PCR for T. cruzi infection diagnosis in triatomines. Triatomines were collected before vector control interventions in Pampa del Indio houses (Argentine Chaco) and examined by OM. We amplified the variable regions of the kinetoplastid minicircle genome (vkDNA-PCR) in DNA extracted from the rectal ampoules of 64 OM-positive and 65 OM-negative T. infestans.
Results: vkDNA-PCR detected T. cruzi infection in 59 (92.2%) OM-positive bugs and in 19 (29.2%) OM-negative triatomines in blind tests. The overall prevalence of infection, as determined by a positive test result by either vkDNA-PCR or OM, was 64.3% [95% confidence interval (95% CI) 55.8-72.1%]. Detection probability of T. cruzi infection by vkDNA-PCR (92%, 95% CI 83-97%) was substantially higher than for OM (76%, 95% CI 65-84%). Infection was minimal (26.2%) in peridomestic nymphs and maximal in domestic adult triatomines (81.7%). In the literature review encompassing 26 triatomine species from 11 countries, inter-method agreement ranged from 28.6% to 100%. The lowest agreement was observed in Rhodnius sp. and Panstrongylus lutzi and the highest among Triatoma sp., with wide variability in the protocols and outcomes of molecular diagnosis in comparison with OM.
Conclusions: Our study provides a synthesis on the different sources (both biological and technical) of variation of the outcomes of OM- and PCR-based diagnosis of T. cruzi infection in triatomines and identifies new research needs for diagnostic improvement.
Competing Interests: Declarations. Ethics approval and consent to participate: The study protocol was reviewed and approved by the Comité de Etica en Investigación Clínica (Ethical Committee for Clinical Research, Buenos Aires). The protocol for household enrollment included explaining the study aims to householders, asking for permission to inspect the premises for triatomine bugs, and providing oral consents. Consent for publication: All authors of this manuscript have read and agreed to the content within it. The contents of this article are original, and the authors consent to the BioMed Central Copyright and License Agreement. Competing interests: The authors declare no competing interests.
(© 2025. The Author(s).)

Parasitology. 2006 Jan;132(Pt 1):57-65. (PMID: 16393354)
J Clin Microbiol. 1996 May;34(5):1171-5. (PMID: 8727897)
Parasit Vectors. 2017 Aug 29;10(1):404. (PMID: 28851417)
PLoS Negl Trop Dis. 2023 Apr 24;17(4):e0011252. (PMID: 37093886)
Ann Trop Med Parasitol. 2007 Jul;101(5):461-5. (PMID: 17550653)
J Invertebr Pathol. 2024 Sep;206:108161. (PMID: 38914370)
Infect Genet Evol. 2014 Jul;25:36-43. (PMID: 24732410)
Exp Parasitol. 1996 Jun;83(1):62-6. (PMID: 8654552)
Am J Trop Med Hyg. 2014 Jun;90(6):1063-73. (PMID: 24732461)
Front Parasitol. 2024 Feb 13;3:1292143. (PMID: 39817172)
Acta Trop. 2021 Dec;224:106130. (PMID: 34536368)
Parasitol Int. 2013 Feb;62(1):36-43. (PMID: 22995149)
PLoS Negl Trop Dis. 2010 Mar 02;4(3):e620. (PMID: 20209149)
PLoS Negl Trop Dis. 2021 May 12;15(5):e0009389. (PMID: 33979344)
Cad Saude Publica. 2008 Oct;24(10):2323-33. (PMID: 18949234)
Parasit Vectors. 2018 Aug 30;11(1):492. (PMID: 30165892)
Sci Rep. 2018 Jan 9;8(1):151. (PMID: 29317702)
Am J Trop Med Hyg. 1999 May;60(5):740-5. (PMID: 10344645)
Sci Data. 2017 Apr 11;4:170050. (PMID: 28398292)
J Invertebr Pathol. 2009 Nov;102(3):233-7. (PMID: 19660466)
Acta Trop. 2018 Aug;184:59-66. (PMID: 29476727)
Acta Trop. 2006 Aug;99(1):50-4. (PMID: 16887092)
PLoS Negl Trop Dis. 2024 Feb 20;18(2):e0011981. (PMID: 38377140)
Trans R Soc Trop Med Hyg. 1990 May-Jun;84(3):439-42. (PMID: 2124395)
Acta Trop. 2009 May-Jun;110(2-3):137-47. (PMID: 18992212)
PLoS Negl Trop Dis. 2015 Oct 23;9(10):e0004186. (PMID: 26496442)
Mem Inst Oswaldo Cruz. 2005 May;100(3):237-9. (PMID: 16113860)
Infect Genet Evol. 2014 Oct;27:105-13. (PMID: 25017654)
J Vector Ecol. 2016 Dec;41(2):285-291. (PMID: 27860015)
PLoS Negl Trop Dis. 2021 Nov 9;15(11):e0009919. (PMID: 34752464)
Infect Genet Evol. 2020 Mar;78:104062. (PMID: 31683004)
Parasit Vectors. 2023 Aug 2;16(1):258. (PMID: 37528423)
Mem Inst Oswaldo Cruz. 2015 May;110(3):277-82. (PMID: 25466622)
Parasitology. 2012 Oct;139(12):1570-9. (PMID: 23036510)
Am J Trop Med Hyg. 1995 Aug;53(2):179-84. (PMID: 7677221)
Parasit Vectors. 2016 Mar 16;9:158. (PMID: 26984679)
PLoS One. 2012;7(9):e46013. (PMID: 23049923)
Bol Chil Parasitol. 1971 Jan-Jun;26(1):57-8. (PMID: 5002112)
Sci Data. 2022 Jun 24;9(1):360. (PMID: 35750679)
PLoS Negl Trop Dis. 2011 Oct;5(10):e1349. (PMID: 22028941)
Trans R Soc Trop Med Hyg. 1996 Nov-Dec;90(6):649-51. (PMID: 9015504)
Acta Trop. 2007 Sep;103(3):201-11. (PMID: 17686448)
Mol Biochem Parasitol. 2002 Apr 9;120(2):305-8. (PMID: 11897137)

UBACYT 20020100100944 Universidad de Buenos Aires; UBACYT 20020130100843BA Universidad de Buenos Aires; PICT 2018-4193 Agencia Nacional de Promoción Científica y Tecnológica; PICT 2019-3079 Agencia Nacional de Promoción Científica y Tecnológica; PICT-2021-Cat1-0081 Agencia Nacional de Promoción Científica y Tecnológica; PIP 11220110101146 Consejo Nacional de Investigaciones Científicas y Técnicas

Keywords: Triatoma infestans; Trypanosoma cruzi; Chagas disease; Diagnosis; Imperfect detection; Occupancy models; PCR; Triatomine

0 (DNA, Protozoan)

Date Created: 20250219 Date Completed: 20250219 Latest Revision: 20250220

20250220

PMC11834302

10.1186/s13071-025-06693-3

39966871