scholarly journals Co-occurrence of kdr mutations V1016I and F1534C in pyrethroid-resistant Aedes aegypti (Diptera: Culicidae) populations from Costa Rica

2019 ◽  
Author(s):  
Aryana Zardkoohi ◽  
David Castañeda ◽  
Carmen Castillo ◽  
Juan C Lol ◽  
Francisco Lopez ◽  
...  

AbstractAedes aegypti (Linnaeus, 1762) is considered the most important mosquito vector species for several arboviruses (e.g., dengue, chikungunya, Zika) in Costa Rica. The main strategy for the control and prevention of Aedes-borne diseases relies on insecticide-based vector control. However, the emergence of insecticide resistance in the mosquito populations present a big threat for the prevention actions. The characterization of the mechanisms driving the insecticide resistance in Ae. aegypti are vital for decision making in vector control programs. Therefore, we analyzed the voltage-gated sodium channel gene for the presence of the V1016I and F1534C kdr mutations in pyrethroid-resistant Ae. aegypti populations from Puntarenas and Limon provinces, Costa Rica. The CDC bottle bioassays showed that both Costa Rican Ae. aegypti populations were resistant to permethrin and deltamethrin. In the case of kdr genotyping, results revealed the co-occurrence of V1016I and F1534C mutations in permethrin and deltamethrin-resistant populations, as well as the fixation of the 1534C allele. Therefore, our findings make an urgent call to expand the knowledge about the insecticide resistance status and mechanisms in the Costa Rican populations of Ae. aegypti which must be a priority to develop an effective resistance management plan.

2019 ◽  
Vol 57 (3) ◽  
pp. 830-836
Author(s):  
Aryana Zardkoohi ◽  
David Castañeda ◽  
Juan C Lol ◽  
Carmen Castillo ◽  
Francisco Lopez ◽  
...  

Abstract Aedes aegypti (Linnaeus, 1762) is considered the most important mosquito vector species for several arboviruses (e.g., dengue, chikungunya, Zika) in Costa Rica. The primary strategy for the control and prevention of Aedes-borne diseases relies on insecticide-based vector control. However, the emergence of insecticide resistance in the mosquito populations presents a significant threat to these prevention actions. The characterization of the mechanisms driving the insecticide resistance in Ae. aegypti is vital for decision making in vector control programs. Therefore, we analyzed the voltage-gated sodium channel (VGSC) gene for the presence of the V1016I and F1534C kdr mutations in Ae. aegypti populations from Puntarenas and Limon provinces, Costa Rica. The CDC bottle bioassays showed that both Costa Rican Ae. aegypti populations were resistant to permethrin and deltamethrin. In the case of kdr genotyping, results revealed the co-occurrence of V1016I and F1534C mutations in permethrin and deltamethrin-resistant populations, as well as the fixation of the 1534C allele. A strong association between these mutations and permethrin and deltamethrin resistance was found in Puntarenas. Limon did not show this association; however, our results indicate that the Limon population analyzed is not under the same selective pressure as Puntarenas for the VGSC gene. Therefore, our findings make an urgent call to expand the knowledge about the insecticide resistance status and mechanisms in the Costa Rican populations of Ae. aegypti, which must be a priority to develop an effective resistance management plan.


2011 ◽  
Vol 101 (4) ◽  
pp. 435-441 ◽  
Author(s):  
K.A. Polson ◽  
S.C. Rawlins ◽  
W.G. Brogdon ◽  
D.D. Chadee

AbstractInsecticide resistance is an important factor in the effectiveness of Aedes aegypti control and the related spread of dengue. The objectives of this study were to investigate the status of the organochlorine dichlorodiphenyltrichloroethane (DDT) and pyrethroid (permethrin and deltamethrin) resistance in Trinidad and Tobago populations of Ae. aegypti and the underlying biochemical mechanisms. Nine populations of Ae. aegypti larvae from Trinidad and Tobago were assayed to DDT and PYs using the Centers for Disease Control and Prevention (CDC) time-mortality-based bioassay method. A diagnostic dosage (DD) was established for each insecticide using the CAREC reference susceptible Ae. aegypti strain and a resistance threshold (RT), time in which 98–100% mortality was observed in the CAREC strain, was calculated for each insecticide. Mosquitoes which survived the DD and RT were considered as resistant, and the resistance status of each population was categorised based on the WHO criteria with mortality <80% indicative of resistance. Biochemical assays were conducted to determine the activities of α and β esterases, mixed function oxidases (MFO) and glutathione-S-transferases (GST) enzymes which are involved in resistance of mosquitoes to DDT and PYs. Enzymatic activity levels in each population were compared with those obtained for the CAREC susceptible strain, and significant differences were determined by Kruskal-Wallis and Tukey's non-parametric tests (P<0.05). The established DDs were 0.01 mg l−1, 0.2 mg l−1 and 1.0 mg l−1 for deltamethrin, permethrin and DDT, respectively; and the RTs for deltamethrin, permethrin and DDT were 30, 75 and 120 min, respectively. All Ae. aegypti populations were resistant to DDT (<80% mortality); two strains were incipiently resistant to deltamethrin and three to permethrin (80–98% mortality). Biochemical assays revealed elevated levels of α-esterase and MFO enzymes in all Ae. aegypti populations. All, except three populations, showed increased levels of β-esterases; and all populations, except Curepe, demonstrated elevated GST levels.Metabolic detoxification of enzymes is correlated with the manifestation of DDT and PY resistance in Trinidad and Tobago populations of Ae. aegypti. The presence of this resistance also suggests that knock down (kdr)-type resistance may be involved, hence the need for further investigations. This information can contribute to the development of an insecticide resistance surveillance programme and improvement of resistance management strategies aimed at combatting the spread of dengue in Trinidad and Tobago.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Henk van den Berg ◽  
Haroldo Sergio da Silva Bezerra ◽  
Samira Al-Eryani ◽  
Emmanuel Chanda ◽  
Bhupender N. Nagpal ◽  
...  

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.


2021 ◽  
Vol 15 (4) ◽  
pp. e0009358
Author(s):  
Henk van den Berg ◽  
Raman Velayudhan ◽  
Rajpal S. Yadav

Interventions to control the vectors of human diseases, notably malaria, leishmaniasis and dengue, have relied mainly on the action of chemical insecticides. However, concerns have been raised regarding the management of insecticides in vector-borne disease-endemic countries. Our study aimed to analyze how vector control insecticides are managed in selected countries to extract lessons learned. A qualitative analysis of the situation of vector control insecticides management was conducted in six countries. Multi-stakeholder meetings and key informer interviews were conducted on aspects covering the pesticide lifecycle. Findings were compared and synthesized to extract lessons learned. Centrally executed guidelines and standards on the management of insecticides offered direction and control in most malaria programs, but were largely lacking from decentralized dengue programs, where practices of procurement, application, safety, storage, and disposal were variable between districts. Decentralized programs were better at facilitating participation of stakeholders and local communities and securing financing from local budgets. However, little coordination existed between malaria, visceral leishmaniasis and dengue programs within countries. Entomological capacity was concentrated in malaria programs at central level, while dengue and visceral leishmaniasis programs were missing out on expertise. Monitoring systems for insecticide resistance in malaria vectors were rarely used for dengue or visceral leishmaniasis vectors. Strategies for insecticide resistance management, where present, did not extend across programs or sectors in most countries. Dengue programs in most countries continued to rely on space spraying which, considering the realities on the ground, call for revision of international guidelines. Vector control programs in the selected countries were confronted with critical shortcomings in the procurement, application, safety measures, storage, and disposal of vector control insecticides, with implications for the efficiency, effectiveness, and safety of vector control. Further international support is needed to assist countries in situation analysis, action planning and development of national guidelines on vector control insecticide management.


2018 ◽  
Vol 4 (2) ◽  
pp. 83-90
Author(s):  
Ign Joko Suyono ◽  
Aditya K. Karim

Dengue is the most important emerging tropical viral disease of humans in the world today. Aedes aegypti is a major mosquito vector responsible for transmitting many viral diseases and this mosquito that spreads major health problems like dengue fever. The resistance of Ae. aegypti to insecticides is already widespread and represents a serious problem for programmes aimed at the control and prevention of dengue in tropical countries. The search for compounds extracted from medicinal plant preparations as alternatives insecticide for mosquito control is in immediate need. Alternative approach for control Ae. aegypti dan virus dengue using the medicinal plant will be discussed in this paper.Key words: Medicinal plant, Aedes aegypti, dengue fever, dengue haemorragi fever, dengue shock syndrome


2020 ◽  
Vol 14 ◽  
pp. 117863022095279
Author(s):  
Stephanie L Richards ◽  
Brian D Byrd ◽  
Michael H Reiskind ◽  
Avian V White

Mosquito insecticide resistance (IR) is a growing global issue that must be addressed to protect public health. Vector control programs (VCPs) should regularly monitor local mosquito populations for IR and plan control measures accordingly. In some cases, state/federal resources financially support this testing with expertise and/or training programs. Standardization of methods (eg, Centers for Disease Control and Prevention bottle bioassay, World Health Organization tube testing, dose-mortality bioassay) for monitoring IR must be prioritized. One solution is regional hubs of IR monitoring at the state or other level. Training programs on methodology and interpretation of results should be developed and routinely offered to local VCPs conducting IR testing in mosquitoes. Here, current methods for assessing mosquito IR are discussed and insights into a variety of questions from VCPs are considered. It is critical that methods for IR monitoring and data interpretation are standardized through routine training, with the goal of evidence-driven decision making to improve control of mosquitoes and mosquito-borne disease.


Author(s):  
Adedayo Olatunbosun-Oduola ◽  
Ezra Abba ◽  
Olukayode Adelaja ◽  
Adeolu Taiwo-Ande ◽  
Kennedy Poloma-Yoriyo ◽  
...  

Background: Timely entomological and insecticide resistance monitoring is a key to generating relevant data for vector management. We investigated the insecticide susceptibility status of Anopheles gambiae s.l. in eight rural farming communities in Southern Gombe, Nigeria. Methods: Overall, 3–5 days-old adult female Anopheles mosquitoes reared from field-collected immature stages between September and November, 2014 were exposed to the diagnostic doses of pyrethroids, organophosphate and carbamate insecticides using the Center for Disease Control Bottle bioassay. The observatory knockdown time from exposure to each insecticide was recorded up to two hours. The dead mosquitoes were then identified morphological­ly and by molecular assays. Results: Mortality results showed resistance in An. gambiae s.l. populations to bendiocarb (2.3–100%), deltamethrin (39–70%), pirimiphos-methyl (65–95%), dichloro-diphenyl-trichloroethane (0–38.1%), permethrin (0–46.3%) and lambda-cyhalothrin (42.5–86.4%). The few cases of full susceptibility were observed from lamdacyhalothrin exposed population of An. gambiae s.l. in Banbam and Pantami respectively. An. gambiae 177 (45%) was significantly higher (P< 0.05) than An. arabiensis 64 (16.3%), An. coluzzii 34 (8.7%) and An. gambiae/An. coluzzii hybrid 78 (19.8%). Conclusion: A strong evidence of widespread resistance in the major malaria vector species in Southern Gombe to all common classes of insecticides is a justification for the State Malaria Elimination Programme to consciously con­sider incorporating insecticide resistance management strategies into control programs in order to sustain the future of current control interventions


2020 ◽  
Author(s):  
Ashwaq Madani Alnazawi ◽  
Simon Ashall ◽  
David Weetman

Vector control programs worldwide are facing the challenge of mosquitoes becoming resistant to available insecticides. Larviciding is a crucial preventative measure for dengue control but data on insecticide resistance of larval Ae. aegypti in the Middle Eastern Region are limited. This study assesses the susceptibility status of Ae. aegypti collected from the two most important dengue foci in Saudi Arabia, Jeddah and Makkah, to important chemical and biological larvicides; the organophosphate temephos and Bacillus thuringiensis israelensis, Bti). Whilst worldwide, and particularly in Latin America, high-level resistance to temephos is common, Jeddah and Makkah populations exhibited full susceptibility to both temephos and Bti. These data suggest each can be considered by vector control programs for preventative dengue control in the region, as part of temporal rotations or spatial mosaics to manage insecticide resistance.


2020 ◽  
Vol 8 (1) ◽  
pp. 54-68
Author(s):  
Deswandi W. S. Berri ◽  
Julianty Almet ◽  
Diana Agustiani Wuri

Dengue hemorrhagic fever (DHF) is a disease that is found in some tropical and subtropical regions. This disease is caused by dengue virus and is transmitted to humans through the bite of the Aedes aegypti mosquito. the solution taken in controlling DHF is to break the life cycle of the Aedes aegypti mosquito. Vector control is generally carried out using synthetic larvicides, namely abate / temefos, but the use of abate can cause residues, environmental pollution, poisoning and resistance of the eradicated vectors so that natural larvasides from plants are needed namely temulawak rhizome (Curcuma xanthorrhiza Roxb.) for vector control. The purpose of this study was to determine whether temulawak rhizome extract was effective or not in killing Aedes aegypti larvae. This research method includes larva collection, identification and maintenance of mosquitoes, determining sample size, making extracts and testing effectiveness. This study used a control and experiment group with 3 repetitions in the minutes to 15, 30, 45, 60 and 1440 (24 Hours). The control group was positive control using abate and negative control using aquades while the eksperiment group used extract of temulawak rhizome (Curcuma xanthorrhiza Roxb.) with concentrations of 0.6%, 0.8%, 1%, 1.2% and 1.5%. The results of this study indicate that the temulawak rhizome extract (Curcuma xanthorrhiza Roxb.) effective as larvicides because at the lowest concentration 0.6% can kill 100% Aedes aegypti larvae.


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