Fitness of pyrethroid resistance inTriatoma infestans, a vector of Chagas disease

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.

Download Full-text

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

Download Full-text

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.

Download Full-text