Examining Mechanisms of Pyrethroid Resistance in Eggs of Two Populations of the Chagas’ Disease VectorTriatoma infestans(Hemiptera: Reduviidae)

Triatomines are blood-sucking bugs that occur mainly in Latin America. They are vectors of Trypanosoma cruzi, the parasite that causes Chagas disease. Chemical control of Chagas disease´s vectors by using pyrethroid insecticides has been highly successful for the elimination of domestic infestation and consequently the reduction of the vector transmission. However, at the beginning of the 2000s a decrease in the effectiveness of the chemical control of triatomines was detected in several areas from Argentina and Bolivia, particularly in the Gran Chaco eco-region.During the last 15 years, several studies demonstrated the evolution of insecticide resistance in Triatoma infestans and established the presence of different toxicological profiles, the autosomal inherence of resistance, the biological costs of deltamethrin resistance, the expression of deltamethrin resistance thorough the embryonic development, and the main mechanisms of resistance (target-site insensitivity and metabolic detoxification of insecticides).The emergence of pyrethroid resistance coupled with the usual difficulties in sustaining adequate rates of insecticide applications emphasize the need of incorporating other tools for integrated vector and disease control, such as the proposal of the organo-phosphorus insecticide fenitrothion as an alternative chemical strategy for the management of the resistance because it was effective against pyrethroid-resistant populations in laboratory and semi-field trials.New studies on the current situation of presence and spread of resistant populations of triatomines and the acceptance of the use of alternative insecticides are critical requirements in the implementation of strategies for the management of resistance and for the rational design of campaigns oriented to reducing the vector transmission of Chagas’ disease.

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Cytochrome P450 monooxigenase genes (CYP) associated with pyrethroid resistance in the Chagas disease vectorTriatoma infestans

10.1603/ice.2016.113310 ◽

2016 ◽

Author(s):

Nicolás Pedrini

Keyword(s):

Cytochrome P450 ◽

Chagas Disease ◽

Pyrethroid Resistance

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Recent trends in global insecticide use for disease vector control and potential implications for resistance management

Scientific Reports ◽

10.1038/s41598-021-03367-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Henk van den Berg ◽

Haroldo Sergio da Silva Bezerra ◽

Samira Al-Eryani ◽

Emmanuel Chanda ◽

Bhupender N. Nagpal ◽

...

Keyword(s):

Insecticide Resistance ◽

Vector Control ◽

Chagas Disease ◽

Pyrethroid Resistance ◽

Resistance Management ◽

Insecticide Treated Nets ◽

Vector Borne Diseases ◽

Control Programs ◽

Disease Vector ◽

Vector Borne

AbstractInsecticides have played a major role in the prevention, control, and elimination of vector-borne diseases, but insecticide resistance threatens the efficacy of available vector control tools. A global survey was conducted to investigate vector control insecticide use from 2010 to 2019. Out of 140 countries selected as sample for the study, 87 countries responded. Also, data on ex-factory deliveries of insecticide-treated nets (ITNs) were analyzed. Insecticide operational use was highest for control of malaria, followed by dengue, leishmaniasis and Chagas disease. Vector control relied on few insecticide classes with pyrethroids the most used overall. Results indicated that IRS programs have been slow to react to detection of pyrethroid resistance, while proactive resistance management using insecticides with unrelated modes of action was generally weak. The intensive use of recently introduced insecticide products raised concern about product stewardship regarding the preservation of insecticide susceptibility in vector populations. Resistance management was weakest for control of dengue, leishmaniasis or Chagas disease. Therefore, it will be vital that vector control programs coordinate on insecticide procurement, planning, implementation, resistance monitoring, and capacity building. Moreover, increased consideration should be given to alternative vector control tools that prevent the development of insecticide resistance.

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Biological Parameters of Two Triatoma protracta Subspecies (Hemiptera: Reduviidae)

Journal of Medical Entomology ◽

10.1093/jme/tjab158 ◽

2021 ◽

Author(s):

B Nogueda-Torres ◽

J A Martínez-Ibarra ◽

M Barboza-López ◽

O D Montañez-Valdez ◽

J G Michel-Parra

Keyword(s):

United States ◽

Chagas Disease ◽

Geographic Origin ◽

The United States ◽

Mortality Rates ◽

Life Cycles ◽

Biological Parameters ◽

Route Of Transmission ◽

Two Populations ◽

Blood Meals

Abstract In recent years, concerns about Chagas disease in the United States have increased. Triatomine bug (Hemiptera: Reduviidae) populations are the vectors of the parasite Trypanosoma cruzi Chagas (Trypanosomatida: Trypanosomatidae), which causes Chagas disease, although the route of transmission is considered inefficient in United States. However, more studies on triatomine feeding and defecation behavior are needed. In this study, six related biological parameters from two populations of Triatoma protracta protracta (Uhler) and T. p. woodi (Uhler) from Mexican locations near the U.S. border were evaluated. The four population life cycles were less than 6 mo (161–171 d), with 9–10 blood meals needed to molt. Mortality rates were similar (31–38%) among the four populations. Triatoma p. woodi from Hidalgo, Coahuila was the most aggressive one. Feeding times were over 10 min, increasing with instar in all populations. Defecation behaviors varied among populations. High percentages of male and female fourth- and fifth-instar nymphs of T. p. protracta from Imuris and both populations of T. p. woodi defecated immediately after or <1 min of feeding. Lower percentages were observed for T. p. protracta from Jacumé. Because most parameters were similar among the four populations, independent of their subspecies and their geographic origin, we considered that T. p. protracta and T. p. woodi are efficient vectors of T. cruzi. In contrast, defecation patterns were noticeably different among some of the four triatomine populations studied. Our results highlight the importance of studying the biological parameters of local triatomine populations. They also contribute to increasing the knowledge of North American triatomine behavior and defecation patterns.

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Identification of a point mutation associated with pyrethroid resistance in the para-type sodium channel of Triatoma infestans, a vector of Chagas’ disease

Infection Genetics and Evolution ◽

10.1016/j.meegid.2011.12.006 ◽

2012 ◽

Vol 12 (2) ◽

pp. 487-491 ◽

Cited By ~ 40

Author(s):

Jésica Fabro ◽

Marcos Sterkel ◽

Natalia Capriotti ◽

Gastón Mougabure-Cueto ◽

Mónica Germano ◽

...

Keyword(s):

Sodium Channel ◽

Point Mutation ◽

Chagas Disease ◽

Pyrethroid Resistance ◽

Triatoma Infestans

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706 B-type natriuretic peptide (BNP) and ventricular arrhythmias in Chagas disease

European Journal of Heart Failure Supplements ◽

10.1016/s1567-4215(07)60435-4 ◽

2007 ◽

Vol 6 (1) ◽

pp. 155-156

Author(s):

J MARQUES ◽

A KANSKY ◽

I MENDOZA ◽

L LOPEZGOMEZ ◽

F MOLEIRO ◽

...

Keyword(s):

Natriuretic Peptide ◽

Chagas Disease ◽

Ventricular Arrhythmias

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Comparison of Principal Component Solutions in Two Populations

Methodology ◽

10.1027/1614-2241/a000099 ◽

2016 ◽

Vol 12 (1) ◽

pp. 11-20 ◽

Cited By ~ 1

Author(s):

Gregor Sočan

Keyword(s):

Simulation Study ◽

Principal Components ◽

Common Factor ◽

Principal Component ◽

Component Model ◽

Bootstrap Procedure ◽

Factor Loadings ◽

Component Loadings ◽

Principal Component Model ◽

Two Populations

Abstract. When principal component solutions are compared across two groups, a question arises whether the extracted components have the same interpretation in both populations. The problem can be approached by testing null hypotheses stating that the congruence coefficients between pairs of vectors of component loadings are equal to 1. Chan, Leung, Chan, Ho, and Yung (1999) proposed a bootstrap procedure for testing the hypothesis of perfect congruence between vectors of common factor loadings. We demonstrate that the procedure by Chan et al. is both theoretically and empirically inadequate for the application on principal components. We propose a modification of their procedure, which constructs the resampling space according to the characteristics of the principal component model. The results of a simulation study show satisfactory empirical properties of the modified procedure.

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