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Identification of blood meal sources in species of genus Rhodnius in four different environments in the Brazilian amazon. Acta Trop 2022; 232:106486. [PMID: 35525313 DOI: 10.1016/j.actatropica.2022.106486] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 04/22/2022] [Accepted: 04/24/2022] [Indexed: 11/20/2022]
Abstract
Chagas disease is a zoonotic disease caused by the hemoflagellate Trypanosoma cruzi and transmitted primarily by triatomine vectors. Triatomines are hematophagous insects that feed on a variety of vertebrate hosts. The Chagas disease transmission cycle is closely related to the interactions between vectors, parasites, and vertebrate hosts. Knowledge of triatomine food sources is critical to understanding Chagas disease transmission dynamics. The aim of this study was to identify blood meal sources used by triatomines from different environments in the Brazilian Amazon. A total of 25 captures were conducted in four environments. Triatomine specimens were captured on palm trees and were identified by morphological and morphometric characters. Blood meal sources identification was conducted using a traditional PCR followed by Sanger sequencing of mtDNA cytb gene. Sequencing was successful in 167 specimens and a total of 21 blood meal sources were identified: two reptilians, six birds, and 13 mammals. Among these 21 species, three (Tamandua tetradactyla, Didelphis marsupialis and Rattus rattus) are considered reservoir of T. cruzi. Knowledge of the relationship between triatomines and possible reservoirs can help to elucidate the enzootic cycle of T. cruzi in the Amazon region and guide control strategies for Chagas disease transmission in that region.
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Rojas de Arias A, Messenger LA, Rolon M, Vega MC, Acosta N, Villalba C, Marcet PL. Dynamics of Triatoma infestans populations in the Paraguayan Chaco: Population genetic analysis of household reinfestation following vector control. PLoS One 2022; 17:e0263465. [PMID: 35143523 PMCID: PMC8830694 DOI: 10.1371/journal.pone.0263465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 01/19/2022] [Indexed: 11/28/2022] Open
Abstract
Background Although domestic infestations by Triatoma infestans have been successfully controlled across Latin America, in areas of the Gran Chaco region, recurrent post-spraying house colonization continues to be a significant challenge, jeopardizing Chagas disease vector control and maintaining active Trypanosoma cruzi transmission. Methodology/Principal findings To investigate the dynamics of triatomine reinfestation in a rural area of the Paraguayan Chaco, genetic characterization (based on 10 microsatellite loci and cytochrome B sequence polymorphisms) was performed on baseline and reinfestant T. infestans (n = 138) from four indigenous communities and adjacent sylvatic sites. House quality and basic economic activities were assessed across the four communities. Significant genetic differentiation was detected among all baseline triatomine populations. Faster reinfestation was observed in the communities with higher infestation rates pre-spraying. Baseline and reinfestant populations from the same communities were not genetically different, but two potentially distinct processes of reinfestation were evident. In Campo Largo, the reinfestant population was likely founded by domestic survivor foci, with reduced genetic diversity relative to the baseline population. However, in 12 de Junio, reinfestant bugs were likely derived from different sources, including survivors from the pre-spraying population and sympatric sylvatic bugs, indicative of gene-flow between these habitats, likely driven by high human mobility and economic activities in adjacent sylvatic areas. Conclusions/Significance Our results demonstrate that sylvatic T. infestans threatens vector control strategies, either as a reinfestation source or by providing a temporary refuge during insecticide spraying. Passive anthropogenic importation of T. infestans and active human interactions with neighboring forested areas also played a role in recolonization. Optimization of spraying, integrated community development and close monitoring of sylvatic areas should be considered when implementing vector control activities in the Gran Chaco.
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Affiliation(s)
- Antonieta Rojas de Arias
- Centro para el Desarrollo de la Investigación Científica (CEDIC/Díaz Gill Medicina Laboratorial /FMB), Asunción, Paraguay
- * E-mail:
| | - Louisa Alexandra Messenger
- Division of Parasitic Diseases and Malaria (DPDM), Centers for Diseases Control and Prevention (CDC), Entomology Branch, Atlanta, GA, United States of America
- American Society for Microbiology, NW Washington, DC, United States of America
- Department of Disease Control, Faculty of Infectious Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Miriam Rolon
- Centro para el Desarrollo de la Investigación Científica (CEDIC/Díaz Gill Medicina Laboratorial /FMB), Asunción, Paraguay
| | - María Celeste Vega
- Centro para el Desarrollo de la Investigación Científica (CEDIC/Díaz Gill Medicina Laboratorial /FMB), Asunción, Paraguay
| | - Nidia Acosta
- Departamento de Medicina Tropical, Instituto de Investigaciones en Ciencias de la Salud, UNA, Asuncion, Paraguay
| | - Cesia Villalba
- Programa Nacional de Control de la Enfermedad de Chagas (SENEPA), Asunción, Paraguay
| | - Paula L. Marcet
- Division of Parasitic Diseases and Malaria (DPDM), Centers for Diseases Control and Prevention (CDC), Entomology Branch, Atlanta, GA, United States of America
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Cardozo M, Fiad FG, Crocco LB, Gorla DE. Triatominae of the semi-arid Chaco in central Argentina. Acta Trop 2021; 224:106158. [PMID: 34599887 DOI: 10.1016/j.actatropica.2021.106158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 09/20/2021] [Accepted: 09/22/2021] [Indexed: 10/20/2022]
Abstract
The epidemiological scenario in central Argentinian Chaco region shows persistence of Triatoma infestans domestic populations in endemic areas, with control interventions historically affected by the economic instability of the region. Considering this situation, we aimed to (i) update the information regarding to the diversity of triatomines present in domestic, peridomestic and sylvatic environments in departments historically endemic of the Chaco region, (ii) to report the occurrence of secondary vectors of Chagas disease invading domestic environments and (iii) to discuss the possible sources of dispersal of these sylvatic species towards anthropic habitats. Between November 2017 and March 2020, we visited fourteen rural communities of northwest Córdoba province (central Argentina). Entomological data were collected through community vector surveillance in domiciles, active search in peridomiciles and the use of light and yeast traps in sylvatic environments. Seven Triatominae species were captured invading domiciles (T. guasayana, T. garciabesi, T. platensis, T. delpontei, T. breyeri, Panstrongylus guentheri and T. infestans). T. guasayana and T. garciabesi were the species with the highest number of captures. The 32% of the peridomiciles registered infestation with T. infestans (n = 355), mostly in chicken coops and goat pens. In sylvatic environments, T. garciabesi, T. guasayana, T. infestans and P. guentheri were collected. Only one adult specimen of T. infestans was positive for the presence of Trypanosoma cruzi. Our results suggest that the persistence of T. infestans populations in peridomiciles continues to be a serious challenge for control programs, whereas the finding of secondary vectors of Chagas disease actively invading domiciles emphasizes the need to implement new strategies for entomological surveillance.
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Ortega-Pacheco A, Poot-Ramos A, Chan-Pérez JI, Gutiérrez-Blanco E, Acevedo-Arcique CM, Baak-Baak CM, Jiménez-Coello M. Evaluation of the effectiveness of fluralaner against adult stages of Rhodnius prolixus in dogs. Parasitol Int 2021; 87:102508. [PMID: 34781015 DOI: 10.1016/j.parint.2021.102508] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Revised: 10/26/2021] [Accepted: 11/06/2021] [Indexed: 11/29/2022]
Abstract
Triatomines are vectors of American Trypanosomiasis also known as Chagas´ disease where several reservoirs including dogs are involved in the transmission cycle of the causal agent (Trypanosoma cruzi). Considering that the prevalence of American trypanosomiasis in dogs is higher than in humans and that dogs in addition are susceptible of this disease, and are involved in peridomestic transmission to humans, the search for new alternatives for vector control of the triatomines responsible for transmission in dogs is required. Over the 20 weeks the study lasted, 600 individual female, adult of Rhodnius prolixus were offered to the 15 dogs treated with a single oral dose of Fluralaner (Bravecto®, MSD). Feeding pattern of triatomines was not affected by the treatment during the whole study. The fluralaner-induced mortality of R. prolixus had a significant effect until week 12 at which time 100% mortality was observed. Mortality decreased to 67.5% at week 16 to practically nil 0.8% on week 20. Fluralaner achieved 100% mortality of triatomines between 12- and 48-h post-feeding. It was demonstrated that a single oral dose of fluralaner in dogs is highly effective in producing mortality in adult R. prolixus for the time guaranteed by the manufacturer for other blood-sucking insects, with a considerable effective residual effect for up to 16 weeks. Due to this high efficacy, fluralaner could be considered in strategies to control the transmission vectors of Chagas disease in dogs and in turn decrease the peri-domestic transmission cycle, particularly in hyperendemic areas.
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Affiliation(s)
- Antonio Ortega-Pacheco
- Departamento de Salud Animal y Medicina Preventiva, Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Yucatán, Mexico
| | - Anabel Poot-Ramos
- Departamento de Salud Animal y Medicina Preventiva, Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Yucatán, Mexico
| | - Jose I Chan-Pérez
- Centro de Investigaciones Regionales "Dr Hideyo Noguchi", Universidad Autónoma de Yucatán, Mexico
| | - Eduardo Gutiérrez-Blanco
- Departamento de Salud Animal y Medicina Preventiva, Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Yucatán, Mexico
| | | | - Carlos M Baak-Baak
- Centro de Investigaciones Regionales "Dr Hideyo Noguchi", Universidad Autónoma de Yucatán, Mexico
| | - Matilde Jiménez-Coello
- Centro de Investigaciones Regionales "Dr Hideyo Noguchi", Universidad Autónoma de Yucatán, Mexico.
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Riva MM, Pastor FM, Almeida YV, Duarte LM, Souza LIS, Zanini MS, da Silva MA. Detection of Leishmania (Viannia) braziliensis in bats from Espírito Santo, Brazil (2018-2019). Parasitol Res 2021; 120:3857-3863. [PMID: 34499197 DOI: 10.1007/s00436-020-07042-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 12/28/2020] [Indexed: 11/25/2022]
Abstract
Studying the occurrence of Leishmania in bats would help toward clarifying the role of these animals in epidemiological cycles. Therefore, the objective of this study was to detect Leishmania spp. in bats from the Brazilian State of Espírito Santo. In total, 105 bats from 11 species which had been collected from 17 municipalities of Espírito Santo were obtained from the IDAF Rabies Diagnostic Laboratory between December 2018 and June 2019. DNA was extracted from the bone marrow, skin, and spleen samples and analysed using conventional PCR, with primers specific for the kinetoplastic DNA minicircle of the parasitic species Leishmania (Viannnia) braziliensis, Leishmania (Leishmania) infantum, and Leishmania (Leishmania) amazonensis. To identify the Leishmania species, the positive PCR products were analysed using PCR-RFLP with the HaeIII enzyme and 8% polyacrylamide gel electrophoresis. Positivity for L. (V.) braziliensis was observed in five (4.76%) bats: namely, one male Eumops glaucinus from Vitória (in a skin sample), one male Artibeus lituratus from Vila Velha and one female Eumops glaucinus from Vitória (both in bone marrow samples), and one male A. lituratus from Vitória and one male Molossus rufus from Guarapari (both in the spleen samples). To our best knowledge, this is the first report of the detection of Leishmania in bats from Espírito Santo as well as of Leishmania DNA in the bone marrow of bats.
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Affiliation(s)
- Mayara Mezabarba Riva
- Programa de Pós-Graduação em Ciências Veterinárias, Universidade Federal do Espírito Santo, Alto Universitário, s/n, Guararema, Alegre, Espírito Santo, CEP 29.500-000, Brazil
| | - Felipe Martins Pastor
- Programa de Pós-Graduação em Ciências Veterinárias, Universidade Federal do Espírito Santo, Alto Universitário, s/n, Guararema, Alegre, Espírito Santo, CEP 29.500-000, Brazil
| | - Yuri Vieira Almeida
- Departamento de Medicina Veterinária, Universidade Federal do Espírito Santo, Alto Universitário, s/n, Guararema, Alegre, Espírito Santo, CEP 29.500-000, Brazil
| | - Lívia Martino Duarte
- Departamento de Medicina Veterinária, Universidade Federal do Espírito Santo, Alto Universitário, s/n, Guararema, Alegre, Espírito Santo, CEP 29.500-000, Brazil
| | - Lígia Isabelle Silva Souza
- Departamento de Medicina Veterinária, Universidade Federal do Espírito Santo, Alto Universitário, s/n, Guararema, Alegre, Espírito Santo, CEP 29.500-000, Brazil
| | - Marcos Santos Zanini
- Programa de Pós-Graduação em Ciências Veterinárias, Universidade Federal do Espírito Santo, Alto Universitário, s/n, Guararema, Alegre, Espírito Santo, CEP 29.500-000, Brazil
- Departamento de Medicina Veterinária, Universidade Federal do Espírito Santo, Alto Universitário, s/n, Guararema, Alegre, Espírito Santo, CEP 29.500-000, Brazil
| | - Maria Aparecida da Silva
- Programa de Pós-Graduação em Ciências Veterinárias, Universidade Federal do Espírito Santo, Alto Universitário, s/n, Guararema, Alegre, Espírito Santo, CEP 29.500-000, Brazil.
- Departamento de Biologia, Centro de Ciências Exatas, Naturais e da Saúde, Alto Universitário, s/n, Guararema, Alegre, Espírito Santo, CEP 29.500-000, Brazil.
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Queiroga TBD, Gomez LCP, de Sena ER, Dos Santos WV, Ferreira HRP, de Araújo-Neto VT, Barbosa-Silva AN, Brito CRDN, Lima RKDR, Fagundes-Neto JC, Galvão LMDC, de Medeiros HR, da Câmara ACJ, Nascimento MSL, Gama RA, Guedes PMM. Insecticidal efficacy of fluralaner (Bravecto ®) against Triatoma brasiliensis, a major vector of Trypanosoma cruzi in Brazil. Parasit Vectors 2021; 14:456. [PMID: 34488865 PMCID: PMC8422713 DOI: 10.1186/s13071-021-04978-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 08/24/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Triatomines are responsible for the vector transmission of the protozoan parasite Trypanosoma cruzi, which causes Chagas disease. Triatoma brasiliensis is the main vector of the parasite in Brazil, and dogs are an important reservoir of the parasite. The aim of this study was to evaluate the insecticidal effect of fluralaner (Bravecto®) on T. brasiliensis after a blood meal in treated dogs. METHODS Healthy mongrel dogs (n = 8) were recruited from the Zoonoses Control Center (ZCC) in the city of Natal, Rio Grande do Norte, Brazil, and randomized into two groups, a fluralaner (Bravecto®)-treated group (n = 4) and a control group (n = 4). Colony-reared third-, fourth- and fifth-instar nymphs of T. brasiliensis nymphs (n = 10) were allowed to feed on dogs from both groups for 30-40 min, once monthly, for up to 12 months. Bug mortality was observed up to 5 days after each blood meal. RESULTS Mortality in triatomines which had a blood meal on fluralaner (Bravecto®)-treated dogs was 100% for up to 7 months after treatment, with mortality decreasing to 66.4% after 8 months, 57% after 9 months, 35% after 10 months, 10% after 11 months and 0% after 12 months. The mortality of triatomines that fed on non-treated control dogs was always ≤ 2.5%. CONCLUSIONS Our results suggest that fluralaner (Bravecto®) treatment of dogs induces long-term mortality of T. brasiliensis after the blood meal. This is a potential approach to be used to control vector transmission of T. cruzi, the etiological agent of Chagas disease, especially in endemic areas.
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Affiliation(s)
| | | | - Eduardo Rodrigues de Sena
- Graduate Program in Parasitary Biology, Federal University of Rio Grande Do Norte, Natal, Rio Grande Do Norte, Brazil
| | - Wilo Victor Dos Santos
- Graduate Program in Parasitary Biology, Federal University of Rio Grande Do Norte, Natal, Rio Grande Do Norte, Brazil
| | | | - Vicente Toscano de Araújo-Neto
- Graduate Program in Pharmaceutical Sciences, Federal University of Rio Grande Do Norte, Natal, Rio Grande Do Norte, Brazil
| | - Andressa Noronha Barbosa-Silva
- Graduate Program in Pharmaceutical Sciences, Federal University of Rio Grande Do Norte, Natal, Rio Grande Do Norte, Brazil
| | - Carlos Ramon do Nascimento Brito
- Department of Clinical and Toxicological Analyses, Federal University of Rio Grande Do Norte, Natal, Rio Grande Do Norte, Brazil
| | | | | | - Lúcia Maria da Cunha Galvão
- Department of Clinical and Toxicological Analyses, Federal University of Rio Grande Do Norte, Natal, Rio Grande Do Norte, Brazil
| | - Henrique Rocha de Medeiros
- Agricultural School of Jundiaí, Federal University of Rio Grande Do Norte, Macaíba, Rio Grande Do Norte, Brazil
| | - Antônia Cláudia Jácome da Câmara
- Department of Clinical and Toxicological Analyses, Federal University of Rio Grande Do Norte, Natal, Rio Grande Do Norte, Brazil
| | - Manuela Sales Lima Nascimento
- Department of Microbiology and Parasitology, Federal University of Rio Grande Do Norte, Natal, Rio Grande Do Norte, Brazil
| | - Renata Antonaci Gama
- Department of Microbiology and Parasitology, Federal University of Rio Grande Do Norte, Natal, Rio Grande Do Norte, Brazil
| | - Paulo Marcos Matta Guedes
- Department of Microbiology and Parasitology, Federal University of Rio Grande Do Norte, Natal, Rio Grande Do Norte, Brazil.
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Gonzalez Britez NE, Alevi KCC, Caris Garcia AC, Martínez Purroy CE, Galvão C, Carrasco HJ. Chagas Disease Vectors of Paraguay: Entomoepidemiological Aspects of Triatoma sordida (Stål, 1859) and Development of an Identification Key for Paraguayan Triatomines Based on Cytogenetics Data. Am J Trop Med Hyg 2021; 105:130-133. [PMID: 34097644 DOI: 10.4269/ajtmh.20-1454] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 03/22/2021] [Indexed: 11/07/2022] Open
Abstract
Approximately 150,000 people are living with Chagas disease in Paraguay. Although the country has been since 2008 considered as one of the countries that succeeded in interrupted the vector transmission of Chagas by Triatoma infestans in houses of the eastern region, there are nine other species notified in the country that are potential vectors and also deserve attention from vector control programs. Thus, we carried out an entomoepidemiological study of T. sordida in the eastern and western regions of the country and we developed an identification key for Paraguay's triatomines based on cytogenetic data. Between the years 2003 to 2004, 271 specimens of T. sordida were captured in domestic, peridomestic, and wild ecotopes, with 131 insects caught in the eastern (Alto Paraguay, Boquerón and Pte. Hayes) and 140 in the western region of Paraguay (Guairá and Paraguarí). High rates of peridomicillary infestation were observed for both regions. Besides that, the natural infection of the captured insects was detected by optical microscopy in 12% and 10%, and by PCR in 21% and 20% in the eastern and western regions, respectively. Based on cytogenetic data from nine of ten species notified in Paraguay, an identification key was developed to differentiate all taxa. Thus, given the vectorial importance of T. sordida, we highlight the need for continued attention from Paraguay's vector control programs for this species. Further, we provide a taxonomic key that assists in the correct classification of Paraguayan triatomines.
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Affiliation(s)
- Nilsa Elizabeth Gonzalez Britez
- 1Departamento de Medicina Tropical, Instituto de Investigaciones en Ciencias de la Salud (IICS), Universidad Nacional de Asunción, Campus Universitario, San Lorenzo, Paraguay
| | - Kaio Cesar Chaboli Alevi
- 2Universidade Estadual Paulista "Júlio de Mesquita Filho" (UNESP), Instituto de Biociências de Botucatu, Rua Dr. Antônio Celso Wagner Zanin, Distrito de Rubião Junior, Botucatu, SP, Brazil.,3Laboratório de Parasitologia, Universidade Estadual Paulista "Júlio de Mesquita Filho" (UNESP), Faculdade de Ciências Farmacêuticas, Rodovia Araraquara-Jaú km 1, Araraquara, SP, Brazil
| | - Ariane Cristina Caris Garcia
- 2Universidade Estadual Paulista "Júlio de Mesquita Filho" (UNESP), Instituto de Biociências de Botucatu, Rua Dr. Antônio Celso Wagner Zanin, Distrito de Rubião Junior, Botucatu, SP, Brazil
| | - Clara Elena Martínez Purroy
- 4Laboratorio de Biología Molecular de Protozoarios, Facultad de Medicina, Instituto de Medicina Tropical, Universidad Central de Venezuela, Los Chaguaramos, Caracas, Venezuela
| | - Cleber Galvão
- 5Laboratório Nacional e Internacional de Referência em Taxonomia de Triatomíneos, Instituto Oswaldo Cruz (FIOCRUZ), Pavilhão Rocha Lima, Rio de Janeiro, RJ, Brazil
| | - Hernán José Carrasco
- 4Laboratorio de Biología Molecular de Protozoarios, Facultad de Medicina, Instituto de Medicina Tropical, Universidad Central de Venezuela, Los Chaguaramos, Caracas, Venezuela
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Alvedro A, Gaspe MS, Milbourn H, Macchiaverna NP, Laiño MA, Enriquez GF, Gürtler RE, Cardinal MV. Trypanosoma cruzi infection in Triatoma infestans and high levels of human-vector contact across a rural-to-urban gradient in the Argentine Chaco. Parasit Vectors 2021; 14:35. [PMID: 33422133 PMCID: PMC7796388 DOI: 10.1186/s13071-020-04534-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 12/10/2020] [Indexed: 11/24/2022] Open
Abstract
Background Peri-urban and urban settings have recently gained more prominence in studies on vector-borne transmission of Trypanosoma cruzi due to sustained rural-to-urban migrations and reports of urban infestations with triatomines. Prompted by the finding of Triatoma infestans across the rural-to-urban gradient in Avia Terai, an endemic municipality of the Argentine Chaco, we assessed selected components of domestic transmission risk in order to determine its variation across the gradient. Methods A baseline vector survey was conducted between October 2015 and March 2016, following which we used multistage random sampling to select a representative sample of T. infestans at the municipal level. We assessed T. cruzi infection and blood-feeding sources of 561 insects collected from 109 houses using kinetoplast DNA-PCR assays and direct enzyme-linked immunosorbent assays, respectively. We stratified triatomines according to their collection site (domestic or peridomestic), and we further categorized peridomestic sites in ecotopes of low- or high-risk for T. cruzi infection. Results The overall adjusted prevalence of T. cruzi-infected T. infestans was 1.8% (95% confidence interval [CI] 1.3–2.3) and did not differ between peri-urban (1.7%) and rural (2.2%) environments. No infection was detected in bugs captured in the urban setting; rather, infected triatomines were mainly collected in rural and peri-urban domiciles, occurring in 8% of T. infestans-infested houses. The main blood-feeding sources of domestic and peridomestic triatomines across the gradient were humans and chickens, respectively. The proportion of triatomines that had fed on humans did not differ between peri-urban (62.5%) and rural (65.7%) domiciles, peaking in the few domestic triatomines collected in urban houses and decreasing significantly with an increasing proportion of chicken- and dog- or cat-fed bugs. The relative odds ratio (OR) of having a T. cruzi infection was nearly threefold higher in bugs having a blood meal on humans (OR 3.15), dogs (OR 2.80) or cats (OR: 4.02) in a Firth-penalized multiple logistic model. Conclusions Trypanosoma cruzi transmission was likely occurring both in peri-urban and rural houses of Avia Terai. Widespread infestation in a third of urban blocks combined with high levels of human–triatomine contact in the few infested domiciles implies a threat to urban inhabitants. Vector control strategies and surveillance originally conceived for rural areas should be tailored to peri-urban and urban settings in order to achieve sustainable interruption of domestic transmission in the Chaco region.![]()
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Affiliation(s)
- Alejandra Alvedro
- Laboratorio de Eco-Epidemiología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.,Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - María Sol Gaspe
- Laboratorio de Eco-Epidemiología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.,Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad de Buenos Aires, Buenos Aires, Argentina
| | | | - Natalia Paula Macchiaverna
- Laboratorio de Eco-Epidemiología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.,Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Mariano Alberto Laiño
- Laboratorio de Eco-Epidemiología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.,Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Gustavo Fabián Enriquez
- Laboratorio de Eco-Epidemiología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.,Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Ricardo Esteban Gürtler
- Laboratorio de Eco-Epidemiología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.,Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Marta Victoria Cardinal
- Laboratorio de Eco-Epidemiología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina. .,Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad de Buenos Aires, Buenos Aires, Argentina.
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