Do the new triatomine species pose new challenges or strategies for monitoring Chagas disease? An overview from 1979-2021

Ecological niche modeling of Triatominae bugs allow us to establish the local risk of transmission of the parasiteTrypanosoma cruzi,which causes Chagas disease.This information could help to guide health authority recommendations on infection monitoring, prevention, and control. In this study, we estimated the geographic distribution of triatomine species in Colombia and identified the relationship between landscape structure and climatic factors influencing their occurrence. A total of 2451 records of 4 triatomine species (Panstrongylus geniculatus,Rhodnius pallescens,R. prolixus, andTriatoma maculata) were analyzed.The variables that provided more information to explain the ecologic niche of these vectors were related to precipitation, altitude, and temperature. We found that the species with the broadest potential geographic distribution wereP. geniculatus,R. pallescens, andR. prolixus. In general, the models predicted the highest occurrence probability of these vectors in the eastern slope of the Eastern Cordillera, the southern region of the Magdalena valley, and the Sierra Nevada of Santa Marta.

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First Report ofAprostocetus asthenogmus(Hymenoptera: Eulophidae) in South America and Parasitizing Eggs of Triatominae Vectors of Chagas Disease

Journal of Parasitology Research ◽

10.1155/2014/547439 ◽

2014 ◽

Vol 2014 ◽

pp. 1-4 ◽

Cited By ~ 1

Author(s):

Claudiney Biral dos Santos ◽

Marcelo Teixeira Tavares ◽

Gustavo Rocha Leite ◽

Adelson Luiz Ferreira ◽

Leonardo de Souza Rocha ◽

...

Keyword(s):

South America ◽

Chagas Disease ◽

Biological Control Agent ◽

Control Agent ◽

Triatoma Infestans ◽

Disease Vectors ◽

Parasitoid Species ◽

Triatomine Species ◽

Chagas Disease Vectors ◽

First Time

We report for the first time the parasitism of eggs of two triatomine Chagas disease vectors,Triatoma infestansandT. vitticeps, by the microhymenopterous parasitoidAprostocetus asthenogmus. We also describe the first identification of this parasitoid in South America.A. asthenogmuswere captured near unparasitized triatomine colonies in the municipality of Vitória, state of Espírito Santo, Brazil, and placed into pots with recently laid triatomine eggs. After 24 days, we observed wasps emerging fromT. infestansandT. vitticepseggs. Several characteristics of this parasitoid species suggest that it could be a potential biological control agent of triatomine species.

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The occurrence of synanthropic triatomines in Bahia, Brazil: what changed after 40 years of the vector-control program?

10.21203/rs.3.rs-50744/v1 ◽

2020 ◽

Author(s):

Gilmar Ribeiro ◽

Cristiane Medeiros Moraes de Carvalho ◽

Renato Freitas de Araújo ◽

Fernanda Cardoso Lanza ◽

Diego Lopes Paim Miranda ◽

...

Keyword(s):

Vector Control ◽

Chagas Disease ◽

Relative Abundance ◽

Disease Transmission ◽

Control Program ◽

The State ◽

Triatoma Infestans ◽

Entomological Surveillance ◽

Triatomine Species ◽

Vector Control Program

Abstract Background: This study presents a descriptive analysis of the occurrence of synanthropic triatomine species in the state of Bahia, before and after the implementation of the vector control program. Methods: Occurrence and number of collected specimens in the municipalities were analyzed in two periods: (A) 1957 to 1971, before systematic vector control actions; and (B) 2006 to 2019, after the certification of interruption of Chagas disease transmission by Triatoma infestans. Results: In total, 17 species were recorded during period A and 21 during period B. Panstrongylus megistus was the most frequent species in period A (42%), while Triatoma pseudomaculata (42%) and T. sordida (38%) were more frequent in period B. In period A, T. infestans was found in 26 (9%) municipalities, and in period B it was found in 7 (2%). During period B, most triatomines (88%) were captured at the peridomestic habitats, with a predominance of T. sordida (85%). Species with greatest relative abundance within the household were T. sordida (49%), T. brasiliensis (27%), and T. pseudomaculata (15%). Conclusions: We have observed a clear reduction in the occurrence of P. megistus and T. infestans and an increase in the relative abundance and geographical distribution of T. sordida and T. pseudomaculata after 40 years of the vector-control program. High frequency of other triatomine species in the municipalities of the state of Bahia and a great abundance of T. sordida in recent years, highlight the need to reinforce permanent entomological surveillance actions for Chagas disease.

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Trends in Taxonomy of Chagas Disease Vectors (Hemiptera, Reduviidae, Triatominae): From Linnaean to Integrative Taxonomy

Pathogens ◽

10.3390/pathogens10121627 ◽

2021 ◽

Vol 10 (12) ◽

pp. 1627

Author(s):

Kaio Cesar Chaboli Alevi ◽

Jader de Oliveira ◽

Dayse da Silva Rocha ◽

Cleber Galvão

Keyword(s):

Chagas Disease ◽

State Of The Art ◽

Integrative Taxonomy ◽

Disease Vectors ◽

Neglected Tropical Disease ◽

Cryptic Speciation ◽

Triatomine Species ◽

Chagas Disease Vectors ◽

First Time ◽

Five Tribes

Chagas disease is a neglected tropical disease caused by the protozoan Trypanosoma cruzi and transmitted mainly by members of the subfamily Triatominae. There are currently 157 species, grouped into 18 genera and five tribes. Most descriptions of triatomine species are based on classical taxonomy. Facing evolutionary (cryptic speciation and phenotypic plasticity) and taxonomic (more than 190 synonymizations) problems, it is evident that integrative taxonomy studies are an important and necessary trend for this group of vectors. Almost two-and-a-half centuries after the description of the first species, we present for the first time the state-of-the-art taxonomy of the whole subfamily, covering from the initial classic studies to the use of integrative taxonomy.

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Lethality of triatomines (Hemiptera: Reduviiae), vectors of Chagas' disease, feeding on blood baits containing synthetic insecticides, under laboratory conditions

Revista do Instituto de Medicina Tropical de São Paulo ◽

10.1590/s0036-46651991000600002 ◽

1991 ◽

Vol 33 (6) ◽

pp. 427-433 ◽

Cited By ~ 4

Author(s):

Marli Maria Lima ◽

Luis Rey ◽

Rubens Pinto de Mello

Keyword(s):

Chagas Disease ◽

Laboratory Study ◽

Room Temperature ◽

Oral Route ◽

Triatoma Infestans ◽

Active Principle ◽

Defibrinated Sheep Blood ◽

Panstrongylus Megistus ◽

Killing Rate ◽

Triatomine Species

A laboratory study was conducted to test the toxicity of synthetic insecticides added to defibrinated sheep blood kept at room temperature and offered as food to the following triatomine species: Triatoma infestans, Panstrongylus megistus, Triatoma vitticeps, Triatoma pseudomaculata, Triatoma brasiliensis and Rhodnius prolixus. The insecticides used, at a concentration of 1g/l, were: HCH, DDT, Malathion and Trichlorfon, and the lethalithy observed at the end of a 7-day period varied according to the active principle of each. HCH was the most effective by the oral route, killing 100% of the insects, except P. megistus (95.7%) and T. pseudomaculata (94.1%). Trichlorfon killed the insects at rates ranging from 71.8% (T. vitticeps) to 98% (R. prolixus). Malathion was slightly less efficient, killing the insects at rates from 56.8% (T. vitticeps) to 97% (T.brasiliensis). DDT was the least effective, with a killing rate of 10% (T. vitticeps) to 75% (T.brasiliensis). Since the tests were performed at room temperature, we suggest that baits of this type should be tried for the control of triatomines in the field.

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Chromosome homogeneity in populations of Triatoma brasiliensis Neiva 1911 (Hemiptera - Reduviidae - Triatominae)

Cadernos de Saúde Pública ◽

10.1590/s0102-311x2000000800009 ◽

2000 ◽

Vol 16 (suppl 2) ◽

pp. S83-S88 ◽

Cited By ~ 20

Author(s):

Francisco Panzera ◽

Ruben Pérez ◽

Paula Nicolini ◽

Sonia Hornos ◽

Jane Costa ◽

...

Keyword(s):

Chagas Disease ◽

Genetic Differences ◽

Chromosome Behavior ◽

Specific Chromosome ◽

Chromosomal Organization ◽

Meiotic Process ◽

Chromosome Differentiation ◽

Semiarid Zone ◽

Triatomine Species

Triatoma brasiliensis is the most important vector of Chagas disease in the semiarid zone of the Northeast of Brazil. Several authors have reported the occurrence of four chromatic patterns with morphological, ecological, and genetic differences. In order to determine the existence of cytogenetic differentiation between these chromatic forms, we analyzed their karyotypes and the chromosome behavior during the male meiotic process. Triatoma brasiliensis shows distinct and specific chromosome characteristics, which differ from those observed in all other triatomine species. However, no cytogenetic differences were observed between the four chromatic forms of T. brasiliensis. The lack of chromosome differentiation among them could indicate that the populations of this species are in a process of differentiation that does not involve their chromosomal organization.

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Comprehensive Survey of Domiciliary Triatomine Species Capable of Transmitting Chagas Disease in Southern Ecuador

PLoS Neglected Tropical Diseases ◽

10.1371/journal.pntd.0004142 ◽

2015 ◽

Vol 9 (10) ◽

pp. e0004142 ◽

Cited By ~ 31

Author(s):

Mario J. Grijalva ◽

Anita G. Villacis ◽

Sofia Ocaña-Mayorga ◽

Cesar A. Yumiseva ◽

Ana L. Moncayo ◽

...

Keyword(s):

Chagas Disease ◽

Triatomine Species ◽

Southern Ecuador ◽

Comprehensive Survey

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Epidemiologic studies of chagas' disease in the urban zone of Teresina. State of Piauí, northeastern Brazil

Revista da Sociedade Brasileira de Medicina Tropical ◽

10.1590/s0037-86821984000400006 ◽

1984 ◽

Vol 17 (4) ◽

pp. 199-203 ◽

Cited By ~ 11

Author(s):

Dalva N. da C. Bento ◽

Ana Z. C. L Branco ◽

Marise R. Freitas ◽

Artur da S. Pinto

Keyword(s):

Chagas Disease ◽

Epidemiologic Studies ◽

Northeastern Brazil ◽

Palm Tree ◽

Natural Focus ◽

Predominant Species ◽

Palm Trees ◽

Urban Zone ◽

Triatomine Species ◽

Infection Index

The triatomine species Rhodnius nasutus and Triatoma pseudomaculata were captured on palm trees Orbignya martiana "babaçu ", in the urban zone of Teresina. This kind of palm tree is largely distributed in Piauí State. The predominant species was R. nasutus; the young in stars predominated. The infestation index of palm trees and the infection index of triatomines by flagellates were 96.0 ana 29.1%, respectively. Marsupiais, bats and a rodent were captured in palm trees. The flagellates found in both triatomines ana marsupiais were morphologically and biologically indistinguishable from Trypanosoma cruzi. Forty seven percent (481/1,025) of triatomines were found concentrated in six palm trees where marsupiais circulated. Of the total of 1,025 triatomines 230 (22%) were infected by flagellates and 53.0% (123/230) of these infected triatomines were present in the same six palm trees. No evidence of triatomine domiciliation or human transmission was observed in the houses in the vicinity of palm trees. The results suggest that marsupiais play an important role in the life-cycle of T. cruzi in this region. The natural focus of Chagas' disease, demonstrated in the present study could represent a potential epidemiological threat.

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Quantitative Imagery Analysis of Spot Patterns for Haplogroup Classification of Triatoma Dimidiata (Latreille, 1811) (Hemiptera: Reduviidae) an Important Vector of Chagas Disease

10.21203/rs.3.rs-78108/v1 ◽

2020 ◽

Author(s):

Daryl David Cruz Flores ◽

Dennis Denis Ávila ◽

Elizabeth Arellano ◽

Carlos N. Ibarra-Cerdeña

Keyword(s):

Chagas Disease ◽

Function Analysis ◽

Spot Pattern ◽

Spot Area ◽

Phylogenetic Studies ◽

The Neural Network ◽

Triatomine Species ◽

Almost All ◽

Correct Discrimination

Abstract Background: Spots and coloring patterns evaluated quantitatively can be used to discrimination and identify possible cryptic species. Triatoma dimidiata (Reduviidae: Triatominae) is one of the main complexes of Chagas disease vector species. Phylogenetic studies have defined three haplogroups for Mexico and part of Central America. In this work, we evaluate the possibility of correctly discriminating among these T. dimidiata haplogroups using the pattern of dorsal spots.Methods: Digital images of the dorsal region of individuals from the three haplogroups were used. We used image processing to extract primary and secondary variables characterizing the dorsal spot pattern. The statistical analysis of the variables included descriptive statistics, non-parametric Kruskal-Wallis tests, Discriminant Function Analysis (DFA), and a neural classification network.Results: A distinctive spot pattern was found for each haplogroup. The most differentiated pattern was presented by haplogroup 2, mainly apparent in the notably larger central spots. Haplogroups 1 and 3 were more similar to each other, but there were consistent differences in the shape and orientation of the spots. Significant differences were found among haplogroups in almost all the variables analyzed, these differences being greater in relative spot area, mean relative area of central spots, central spots Feret diameters, lateral spots Feret diameters and aspect ratio. Both the DFA and the neural network had correct discrimination values above 90%. Conclusions: We conclude that the spot pattern can be reliably used to discriminate among haplogroups, and possibly among triatomine species.

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On the possibility of autochthonous Chagas disease in Roraima, Amazon region, Brazil, 2000-2001

Revista do Instituto de Medicina Tropical de São Paulo ◽

10.1590/s0036-46652005000100008 ◽

2005 ◽

Vol 47 (1) ◽

pp. 45-54 ◽

Cited By ~ 16

Author(s):

José Francisco Luitgards-Moura ◽

José Borges-Pereira ◽

Jane Costa ◽

Patrícia Lago Zauza ◽

Maria Goreti Rosa-Freitas

Keyword(s):

Chagas Disease ◽

Pcr Amplification ◽

Epidemiological Survey ◽

Amazon Region ◽

Northeastern Brazil ◽

Arid Zones ◽

Serological Tests ◽

Transmission Cycle ◽

Triatomine Species ◽

Panstrongylus Geniculatus

Chagas disease has been almost entirely eradicated from the arid zones in Central and Northeastern Brazil where rare or no autochthonous cases have been reported. However, in the last 10 years the disease has increasingly been registered in the Amazon Region. Aiming to investigate the possibility of the occurrence of autochthonous cycle of Chagas disease in Roraima, triatomine collections, vectorial susceptibility studies (this one to be shown elsewhere), parasitological and serological analyses were conducted in three agricultural settlement areas (Rorainópolis, Passarão Project and Ilha Community). Blood-donor candidates were also investigated. This is the first epidemiological survey on Chagas disease conducted in agricultural settlements in Roraima. Triatomine species found were Triatoma maculata, Rhodnius pictipes, Rhodnius robustus and Panstrongylus geniculatus. Trypanosoma cruzi detection analyses included xenodiagnosis, indirect immunofluorescence, indirect hemaglutination, ELISA and kinetoplast PCR amplification. Natural triatomine infection was not found in intestinal contents. Twenty-five adult settlers (1.4% out of 1821, all > 15 year-old, 20 migrants) presented anti-T. cruzi antibodies. Two migrant settlers (from Minas Gerais and Maranhão) tested positive for more than two serological tests, besides either being positive for xenodiagnosis or PCR. Results show that Chagas disease is not endemic in the areas studied. However, all elements of the transmission cycle are present, demanding for an adequate and continuous vigilance.

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