scholarly journals Insecticides Resistance Status of An. gambiae in Areas of Varying Agrochemical Use in Côte D’Ivoire

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Behi K. Fodjo ◽  
Benjamin G. Koudou ◽  
Emmanuel Tia ◽  
Jasmina Saric ◽  
Prisca B. N’dri ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Cote D'ivoire ◽  
Côte D’Ivoire ◽  
Crop Protection ◽  
Malaria Vectors ◽  
Taqman Assay ◽  
Malaria Vector Control ◽  
Cote D’Ivoire ◽  
Côte D'ivoire ◽  
Use Pattern

Background. Insecticide resistance monitoring of the malaria vectors to different classes of insecticides is necessary for resistance management. Malaria vector control management approaches are essentially based on IRS and LLINs. However, insecticide resistance is caused by several sources of selection and in case the selection pressure is from agricultural practices, then measures need to be taken to avoid a failure of the control methods put in place. The current study was undertaken to monitor the susceptibility of vectors to different classes of insecticides in areas of varying agrochemical use patterns. Methods. A survey to determine the agricultural chemical use pattern was undertaken in ten localities across Côte d’Ivoire. In addition, WHO susceptibility tests were carried out on adults Anopheles gambiae s.l. mosquitoes emerging from collected larvae from the sites surveyed. Four insecticides from each class of the four classes of insecticides were evaluated using the standard susceptibility test methods. Furthermore, the target site mutations involved in resistance mechanisms were identified following the Taqman assay protocols and mosquito species were identified using SINE-PCR. Results. The mortalities of all the An. gambiae s.l populations were similar regardless of the pesticide use pattern. The vectors were resistant to DDT, deltamethrin, and bendiocarb in all localities. In contrast, mosquitoes showed high susceptibility to malathion. High frequency of the Kdr-West gene allele was observed (70-100%). A single Kdr-East mutation was identified in a mosquito that harboured both Ace-1 and Kdr-West genes. Conclusion. Cultivated marshlands representing good habitats for mosquito development may deeply contribute to the selection of resistance genes given the intensive use of agrochemical for crop protection. In view of these, special attention must be given to them to mitigate mosquito resistance to insecticides.

scholarly journals Rapid spread of double East- and West-African kdr mutations in wild Anopheles coluzzi from Côte d’Ivoire

2019 ◽  
Vol 4 ◽  
pp. 31 ◽  
Author(s):  
Chouaïbou Seïdou Mouhamadou ◽  
Prisca Bédjou N’Dri ◽  
Behi Kouadio Fodjo ◽  
Christabelle Gba Sadia ◽  
France-Paraudie Kouadio Affoue ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Vector Control ◽  
Cote D'ivoire ◽  
Côte D’Ivoire ◽  
West African ◽  
Malaria Vectors ◽  
Cote D’Ivoire ◽  
Côte D'ivoire ◽  
Rapid Spread ◽  
East And West

Malaria morbidity and mortality rates in Sub-Saharan Africa are increasing. The scale-up of long-lasting insecticidal nets and indoor residual spraying have been the major contributors to the decrease of malaria burden. These tools are now threatened by insecticide resistance in malaria vectors, which is spreading dramatically. After two different real-time polymerase chain reaction molecular characterizations carried out on 70 mosquitoes sampled in the locality of Elibou in southern Côte d’Ivoire, results revealed that 9 mosquitoes from Anopheles coluzzi harbored the double East- and West-African knockdown resistance mutations. In the previous year, only 1 mosquito out of 150 sampled from 10 regions of the country had the same genotype. These results show the rapid spread of insecticide resistance in malaria vectors and highlight the urgent need to diversify the methods of vector control in order to avoid the failure of insecticide-based vector control tools which may favor malaria fatalities.

scholarly journals Use of Insecticides in Agriculture and the Prevention of Vector-Borne Diseases: Population Knowledge, Attitudes, Practices and Beliefs in Elibou, South Côte d’Ivoire

2020 ◽  
Vol 5 (1) ◽  
pp. 36
Author(s):  
Bédjou P. N’Dri ◽  
Kathrin Heitz-Tokpa ◽  
Mouhamadou Chouaïbou ◽  
Giovanna Raso ◽  
Amoin J. Koffi ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Cote D'ivoire ◽  
Côte D’Ivoire ◽  
Malaria Vectors ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Cote D’Ivoire ◽  
Attitudes And Practices ◽  
Côte D'ivoire ◽  
Population Attitudes

People’s knowledge, attitudes, practices and beliefs (KAPB) pertaining to malaria are generally well described. However, little is known about population knowledge and awareness of insecticide resistance in malaria vectors. The aim of this study was to investigate KAPB related to insecticide resistance in malaria vectors due to the use of insecticides in agriculture and the prevention against mosquitoes. In mid-2017, we carried out a cross-sectional survey in Elibou, South Côte d’Ivoire, employing a mixed methods approach. Quantitative data were obtained with a questionnaire addressed to household heads. Interviews were conducted with key opinion leaders, including village chiefs, traditional healers, heads of health centres and pesticide sellers. Focus group discussions were conducted with youth and elders. A total of 203 individuals participated in the questionnaire survey (132 males, 65%). We found that people had good knowledge about malaria and mosquitoes transmitting the disease, while they felt that preventing measures were ineffective. Pesticides were intensively used by farmers, mainly during the rainy season. Among the pesticides used, insecticides and herbicides were most commonly used. While there was poor knowledge about resistance, the interviewees stated that insecticides were not killing the mosquitoes anymore. The main reason given was that insecticides were diluted by the manufacturers as a marketing strategy to sell larger quantities. More than a third of the farmers used agricultural pesticides for domestic purposes to kill weeds or mosquitoes. We observed a misuse of pesticides among farmers, explained by the lack of specific training. In the community, long-lasting insecticidal nets were the most common preventive measure against malaria, followed by mosquito coils and insecticide sprays. The interviewees felt that the most effective way of dealing with insecticide resistance was to combine at least two preventive measures. In conclusion, population attitudes and practices related to insecticides used in agriculture and the prevention against mosquitoes could lead to resistance in malaria vectors, while people’s knowledge about insecticide resistance was limited. There is a need to raise awareness in communities about the presence of resistance in malaria vectors and to involve them in resistance management.

scholarly journals Influence of the agrochemicals used for rice and vegetable cultivation on insecticide resistance in malaria vectors in southern Côte d’Ivoire

2016 ◽  
Vol 15 (1) ◽  
Author(s):  
Mouhamadou S. Chouaïbou ◽  
Behi K. Fodjo ◽  
Gilbert Fokou ◽  
Ouattara F. Allassane ◽  
Benjamin G. Koudou ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Cote D'ivoire ◽  
Côte D’Ivoire ◽  
Malaria Vectors ◽  
Cote D’Ivoire ◽  
Côte D'ivoire ◽  
Vegetable Cultivation

scholarly journals Fine scale spatial investigation of multiple insecticide resistance and underlying target-site and metabolic mechanisms in Anopheles gambiae in central Côte d’Ivoire

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Welbeck A. Oumbouke ◽  
Patricia Pignatelli ◽  
Antoine M. G. Barreaux ◽  
Innocent Z. Tia ◽  
Alphonsine A. Koffi ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Anopheles Gambiae ◽  
Cote D'ivoire ◽  
Côte D’Ivoire ◽  
Pyrethroid Resistance ◽  
Controlled Trial ◽  
Management Strategies ◽  
Cluster Randomised Controlled Trial ◽  
Cote D’Ivoire ◽  
Côte D'ivoire

Abstract Routine monitoring of occurrence, levels and mechanisms of insecticide resistance informs effective management strategies, and should be used to assess the effect of new tools on resistance. As part of a cluster randomised controlled trial evaluating a novel insecticide-based intervention in central Côte d’Ivoire, we assessed resistance and its underlying mechanisms in Anopheles gambiae populations from a subset of trial villages. Resistance to multiple insecticides in An. gambiae s.s. and An. coluzzii was detected across villages, with dose–response assays demonstrating extremely high resistance intensity to the pyrethroid deltamethrin (> 1,500-fold), and mortality following exposure to pyrethroid-treated bednets was low (< 30% mortality in cone bioassays). The 1014F kdr mutation was almost fixed (≥ 90%) in all villages but the 1575Y kdr-amplifying mutation was relatively rare (< 15%). The carbamate and organophosphate resistance-associated Ace-1 G119S mutation was also detected at moderate frequencies (22–43%). Transcriptome analysis identified overexpression of P450 genes known to confer pyrethroid resistance (Cyp9K1, Cyp6P3, and Cyp6M2), and also a carboxylesterase (COEAE1F) as major candidates. Cyp6P3 expression was high but variable (up to 33-fold) and correlated positively with deltamethrin resistance intensity across villages (r2 = 0.78, P = 0.02). Tools and strategies to mitigate the extreme and multiple resistance provided by these mechanisms are required in this area to avoid future control failures.

scholarly journals First report of the East African kdr mutation in an Anopheles gambiae mosquito in Côte d’Ivoire

2017 ◽  
Vol 2 ◽  
pp. 8 ◽  
Author(s):  
Mouhamadou Chouaïbou ◽  
Fodjo Behi Kouadio ◽  
Emmanuel Tia ◽  
Luc Djogbenou
Keyword(s):  
Anopheles Gambiae ◽  
East Africa ◽  
Cote D'ivoire ◽  
Côte D’Ivoire ◽  
Sub Saharan Africa ◽  
Taqman Assay ◽  
East African ◽  
Cote D’Ivoire ◽  
Côte D'ivoire ◽  
Genotype Frequencies

Background. The intensive use of insecticides in public health and agriculture has led to the development of insecticide resistances in malaria vectors across sub-Saharan Africa countries in the last two decades. The kdr target site point mutation which is among the best characterised resistance mechanisms seems to be changing its distribution patterns on the African continent. The 1014F kdr mutation originally described only in West Africa is spreading to East Africa while the 1014S kdr mutation originally described in East Africa, is spreading to West and Central Africa. However, the East-kdr mutation has not been reported in Côte d'Ivoire so far. Methods. Immature stages of Anopheles gambiae s.l. were collected from breeding sites at the outskirts of Yamoussoukro, Côte d'Ivoire. Emerging 3–5 day old adult female mosquitoes were tested for susceptibility to deltamethrin 0.05%, malathion 5%, bendiocarb 1% and dichlorodiphenyltrichloroethane (DDT) 4% according to WHO standard procedures. A total of 50 An. gambiae s.l. specimens were drawn at random for DNA extraction and identification down to the species level. A subsample of 30 mosquitoes was tested for the East-African kdr mutation using a Taqman assay. Results. The tested mosquito population appeared to be strongly resistant to deltamethrin (1.03% mortality), bendiocarb (38.46% mortality) and DDT (0% mortality) with probable resistance observed for malathion (92.47%). Among the 41 mosquitoes that were successfully characterized, An. coluzzii was predominant (68.3%) followed by An. gambiae s.s. (19.5%) and a few hybrids (7.3%). Out of 30 specimens genotyped for East-kdr, a single hybrid mosquito appeared to be heterozygous for the mutation. Conclusion. The present study revealed the presence of the East-kdr mutation in Côte d’Ivoire for the first time in An. gambiae and highlights the urgent need to start monitoring the allele and genotype frequencies.

scholarly journals Anopheles bionomics, insecticide resistance mechanisms, and malaria transmission in the Korhogo area, northern Côte d’Ivoire: a pre-intervention study

Parasite ◽  
2019 ◽  
Vol 26 ◽  
pp. 40 ◽  
Author(s):  
Barnabas Zogo ◽  
Dieudonné Diloma Soma ◽  
Bertin N’Cho Tchiekoi ◽  
Anthony Somé ◽  
Ludovic P. Ahoua Alou ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Anopheles Gambiae ◽  
Malaria Transmission ◽  
Cote D'ivoire ◽  
Rainy Season ◽  
Côte D’Ivoire ◽  
Resistance Mechanisms ◽  
Effective Control ◽  
Cote D’Ivoire ◽  
Côte D'ivoire

A better understanding of malaria transmission at a local scale is essential for developing and implementing effective control strategies. In the framework of a randomized controlled trial (RCT), we aimed to provide an updated description of malaria transmission in the Korhogo area, northern Côte d’Ivoire, and to obtain baseline data for the trial. We performed human landing collections (HLCs) in 26 villages in the Korhogo area during the rainy season (September–October 2016, April–May 2017) and the dry season (November–December 2016, February–March 2017). We used PCR techniques to ascertain the species of the Anopheles gambiae complex, Plasmodium falciparum sporozoite infection, and insecticide resistance mechanisms in a subset of Anopheles vectors. Anopheles gambiae s.l. was the predominant malaria vector in the Korhogo area. Overall, more vectors were collected outdoors than indoors (p < 0.001). Of the 774 An. gambiae s.l. tested in the laboratory, 89.65% were An. gambiae s.s. and 10.35% were An. coluzzii. The frequencies of the kdr allele were very high in An. gambiae s.s. but the ace-1 allele was found at moderate frequencies. An unprotected individual living in the Korhogo area received an average of 9.04, 0.63, 0.06 and 0.12 infected bites per night in September–October, November–December, February–March, and April–May, respectively. These results demonstrate that the intensity of malaria transmission is extremely high in the Korhogo area, especially during the rainy season. Malaria control in highly endemic areas such as Korhogo needs to be strengthened with complementary tools in order to reduce the burden of the disease.

Vectorial Transmission of Malaria in Major Districts of Côte d’Ivoire

2019 ◽  
Vol 57 (3) ◽  
pp. 908-914
Author(s):  
Konan F Assouho ◽  
Akré M Adja ◽  
Négnorogo Guindo-Coulibaly ◽  
Emmanuel Tia ◽  
Affoué M N Kouadio ◽  
...  
Keyword(s):  
Malaria Transmission ◽  
Mass Distribution ◽  
Cote D'ivoire ◽  
Rural Areas ◽  
Urban Areas ◽  
Côte D’Ivoire ◽  
Anopheles Funestus ◽  
Malaria Vectors ◽  
Cote D’Ivoire ◽  
Côte D'ivoire

Abstract To better understand the influence of periodic mass distribution of Long-Lasting Insecticidal Nets (LLINs) on malaria transmission, a 1-yr entomological survey was conducted in three major districts of Côte d’Ivoire. Mosquitoes were sampled by Human Landing Catches (HLC) in urban and rural areas of San Pedro and Abidjan (coastal), and in Yamoussoukro (central). Mosquitoes were identified morphologically and by molecular methods. The Plasmodium falciparum circumsporozoite (CSP) indices were measured by ELISA, and the Entomological Inoculation Rates (EIR) were calculated for each species and area. Anopheles gambiae s.l. Giles (Diptera: Culicidae) and Anopheles nili Theobald (Diptera: Culicidae) were identified in coastal districts, while An. gambiae s.l. and Anopheles funestus Giles (Diptera: Culicidae) were reported in the central district. In urban areas, malaria vectors showed a low aggressiveness (&lt;10 bites per person per night), except in Yamoussoukro, where up to 18.9 b/p/n were recorded. The annual EIR was higher in the central urban area (138.7 infected bites per person per year) than in coastal ones (10–62 ib/p/n). In rural areas, malaria vectors were highly aggressive with an average 13 b/p/n for An. gambiae s.l, 21.2 b/p/n for An. nili and 12 b/p/n for An. funestus. The annual EIR ranged between 94.9 and 193.4 infected bites per person per year. This work indicates that, despite repeated mass distribution of LLINs, malaria transmission remains high and heterogeneous across Côte d’Ivoire. Malaria transmission was lower in coastal urban areas than in the central one, and remains high rural areas where two additional Anopheles vectors are involved in malaria transmission.

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