scholarly journals Assessment of Novel Lehmann’s Funnel Entry Trap Prototypes Performance to Control Malaria Mosquito Populations

2020 ◽  
Author(s):  
Roger Sanou ◽  
Hamidou Maïga ◽  
Etienne M. Bilgo ◽  
P. Simon Sawadogo ◽  
Bazoumana D. Sow ◽  
...  

Abstract BackgroundThere is a global consensus that new intervention tools are needed to cross the last miles in malaria elimination/eradication. In a recent study in Burkina Faso, the Lehmann Funnel Entry Trap (LFET) have shown excellent promise in mosquito densities reducing even in area of high insecticide resistance up to 80%. It requires no chemicals and is self-operated. However, one of the issues of the LFET is the big size of the funnel occupying lot of space inside houses. Here we compared the performance of three new prototypes of LFET with reduced size that combine screening and killing effect on mosquitoes. MethodsThe study was carried out for three months during the rainy season both in low and high malaria vector density sites, Soumousso and Vallée du Kou respectively. The original LFET was modified and 3 new prototypes were produced locally and tested over 3 months (8 days/month) to evaluate their effectiveness in trapping and killing mosquitoes entering houses through the windows. ResultsIn both sites, an overall of 78,435 culicine mosquitoes collected in both traps and houses and most of them were mainly Anopheles gambiae s.l. n= 76,558 (98%) and other species represented n = 1,877 (2%). Of the culicine caught in the trial, n= 55,256 (72%) were collected in traps. The 3 new LFET prototypes reduced the indoor density of mosquitoes collected in the houses by a range of 36 to 73% and 69 to 70% in low vector density setting, Soumousso and high vector density area, Vallée du Kou respectively. The prototype 1 caught a greater number of mosquitoes than the prototype 2 whereas no difference was observed between other prototypes in VK3. In Soumousso, the prototypes 1 and 2 collected significantly higher number of mosquitoes compared to the prototypes 3 and 4. ConclusionThis study has shown that the new LFET prototypes are promising for malaria vector control and could enter in the malaria vector control toolbox in the coming years. Therefore, a large-scale study with one of the prototypes is needed on the practical ability and community acceptance of the LFET to control malaria vectors.

2020 ◽  
Author(s):  
Roger Sanou ◽  
Hamidou Maïga ◽  
Etienne M. Bilgo ◽  
P. Simon Sawadogo ◽  
Bazoumana D. Sow ◽  
...  

Abstract BackgroundThere is a global consensus that new intervention tools are needed to make the final steps toward malaria elimination/eradication. In a recent study in Burkina Faso, the Lehmann Funnel Entry Trap (LFET) has shown promising results in the reduction of mosquito densities, even in areas where insecticide resistance is as high as 80%. The LFET requires no chemicals and is self-operated. However, one of the issues with the original LFET is the size of the funnel, which often occupies too much space within users’ homes. Here, we compared the performance of three new, smaller-sized LFET prototypes that combine a screening and killing effect on mosquitoes. MethodsThe study was carried out over three months during the rainy season in low and high malaria vector density sites, Soumousso and Vallée du Kou, respectively. The original LFET (or ‘Prototype 1’/’P1’) was modified to produce three new prototypes, which we will refer to as Prototype 2 (‘the Medium’ or ‘P2’), Prototype 3 (P3) and Prototype 4 (P4). Each of the new prototypes was tested on eight days per month over the three-month period to assess their effectiveness in trapping and killing mosquitoes entering houses through the windows compared to the original LFET. ResultsOverall, 78,435 mosquitoes (mainly Anopheles gambiae s.l.) were collected in the two study sites, both in the traps and in the houses. A total of 56,430 (72%) mosquitoes were collected from the traps. In Vallée du Kou, the original LFET caught a greater number of mosquitoes than the Medium (prototype 2), whereas no difference was observed between the other new prototypes (3 and 4) and the Medium. In Soumousso, the original and Medium LFETs both collected significantly greater numbers of mosquitoes compared to prototypes 3 and 4. ConclusionThis study has shown that the new LFET prototypes are effective in trapping mosquitoes in high mosquito density settings. A large-scale study with one of the prototypes will be needed to assess community acceptance of the traps and their ability to control malaria vectors.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Roger Sanou ◽  
Hamidou Maïga ◽  
Etienne M. Bilgo ◽  
Simon P. Sawadogo ◽  
Bazoumana B. D. Sow ◽  
...  

Abstract Background There is a global consensus that new intervention tools are needed for the final steps toward malaria elimination/eradication. In a recent study in Burkina Faso, the Lehmann Funnel Entry Trap (LFET) has shown promising results in the reduction of mosquito densities, even in areas where insecticide resistance is as high as 80%. The LFET requires no chemicals and is self-operated. However, one of the issues with the original LFET is the size of the funnel, which often occupies too much space within users’ homes. Here, the performance of three new, smaller-sized LFET prototypes that combine a screening and killing effect on mosquitoes was assessed. Methods The study was carried out over three months during the rainy season in low and high malaria vector density sites, Soumousso and Vallée du Kou, respectively. The original LFET (or ‘Prototype 1’/‘P1’) was modified to produce three new prototypes, which were referred to as prototype 2 (‘the Medium’ or ‘P2’), prototype 3 (P3) and prototype 4 (P4). Each of the new prototypes was tested on eight days per month over the three-month period to assess their effectiveness in trapping and killing mosquitoes entering houses through the windows compared to the original LFET. Results Overall, 78,435 mosquitoes (mainly Anopheles gambiae sensu lato) were collected in the two study sites, both in the traps and in the houses. A total of 56,430 (72%) mosquitoes were collected from the traps. In Vallée du Kou, the original LFET caught a greater number of mosquitoes than the medium (prototype 2), whereas no difference was observed between the other new prototypes (3 and 4) and the medium. In Soumousso, both the original and medium LFETs collected significantly greater numbers of mosquitoes compared to prototypes 3 and 4. Conclusion This study has shown that the new LFET prototypes are effective in trapping mosquitoes in high mosquito density settings. A large-scale study with one of the prototypes will be needed to assess community acceptance of the traps and their ability to control malaria vectors.


2020 ◽  
Author(s):  
Roger Sanou ◽  
Hamidou Maïga ◽  
Etienne M. Bilgo ◽  
Simon P. Sawadogo ◽  
Bazoumana D. Sow ◽  
...  

Abstract Background There is a global consensus that new intervention tools are needed for the final steps toward malaria elimination/eradication. In a recent study in Burkina Faso, the Lehmann Funnel Entry Trap (LFET) has shown promising results in the reduction of mosquito densities, even in areas where insecticide resistance is as high as 80%. The LFET requires no chemicals and is self-operated. However, one of the issues with the original LFET is the size of the funnel, which often occupies too much space within users’ homes. Here, the performance of three new, smaller-sized LFET prototypes that combine a screening and killing effect on mosquitoes was assessed. Methods The study was carried out over three months during the rainy season in low and high malaria vector density sites, Soumousso and Vallée du Kou, respectively. The original LFET (or ‘Prototype 1’/’P1’) was modified to produce three new prototypes, which were referred to as Prototype 2 (‘the Medium’ or ‘P2’), Prototype 3 (P3) and Prototype 4 (P4). Each of the new prototypes was tested on eight days per month over the three-month period to assess their effectiveness in trapping and killing mosquitoes entering houses through the windows compared to the original LFET. Results Overall, 78,435 mosquitoes (mainly Anopheles gambiae sensu lato) were collected in the two study sites, both in the traps and in the houses. A total of 56,430 (72%) mosquitoes were collected from the traps. In Vallée du Kou, the original LFET caught a greater number of mosquitoes than the Medium (prototype 2), whereas no difference was observed between the other new prototypes (3 and 4) and the Medium. In Soumousso, both the original and Medium LFETs collected significantly greater numbers of mosquitoes compared to prototypes 3 and 4. Conclusion This study has shown that the new LFET prototypes are effective in trapping mosquitoes in high mosquito density settings. A large-scale study with one of the prototypes will be needed to assess community acceptance of the traps and their ability to control malaria vectors.


2020 ◽  
Author(s):  
Roger Sanou ◽  
Hamidou Maïga ◽  
Etienne M. Bilgo ◽  
Simon P. Sawadogo ◽  
Bazoumana D. Sow ◽  
...  

Abstract Background: There is a global consensus that new intervention tools are needed to make the final steps toward malaria elimination/eradication. In a recent study in Burkina Faso, the Lehmann Funnel Entry Trap (LFET) has shown promising results in the reduction of mosquito densities, even in areas where insecticide resistance is as high as 80%. The LFET requires no chemicals and is self-operated. However, one of the issues with the original LFET is the size of the funnel, which often occupies too much space within users’ homes. Here, we compared the performance of three new, smaller-sized LFET prototypes that combine a screening and killing effect on mosquitoes. Methods: The study was carried out over three months during the rainy season in low and high malaria vector density sites, Soumousso and Vallée du Kou, respectively. The original LFET (or ‘Prototype 1’/’P1’) was modified to produce three new prototypes, which we will refer to as Prototype 2 (‘the Medium’ or ‘P2’), Prototype 3 (P3) and Prototype 4 (P4). Each of the new prototypes was tested on eight days per month over the three-month period to assess their effectiveness in trapping and killing mosquitoes entering houses through the windows compared to the original LFET. Results: Overall, 78,435 mosquitoes (mainly Anopheles gambiae s.l.) were collected in the two study sites, both in the traps and in the houses. A total of 56,430 (72%) mosquitoes were collected from the traps. In Vallée du Kou, the original LFET caught a greater number of mosquitoes than the Medium (prototype 2), whereas no difference was observed between the other new prototypes (3 and 4) and the Medium. In Soumousso, both the original and Medium LFETs collected significantly greater numbers of mosquitoes compared to prototypes 3 and 4. Conclusion: This study has shown that the new LFET prototypes are effective in trapping mosquitoes in high mosquito density settings. A large-scale study with one of the prototypes will be needed to assess community acceptance of the traps and their ability to control malaria vectors.


PLoS ONE ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. e0224718 ◽  
Author(s):  
Maxwell G. Machani ◽  
Eric Ochomo ◽  
Fred Amimo ◽  
Jackline Kosgei ◽  
Stephen Munga ◽  
...  

2019 ◽  
Author(s):  
D.D Soma ◽  
B Zogo ◽  
P Taconet ◽  
A Somé ◽  
S Coulibaly ◽  
...  

AbstractBackgroundTo sustain the efficacy of malaria vector control, the World Health Organization (WHO) recommends the combination of effective tools. Before designing and implementing additional strategies in any setting, it is critical to monitor or predict when and where transmission occurs. However, to date, very few studies have quantified the behavioural interactions between humans and Anopheles vectors. Here, we characterized residual transmission in a rural area of Burkina Faso where long lasting insecticidal nets (LLIN) are widely used.MethodsWe analysed data on both human and malaria vectors behaviours from 27 villages to measure hourly human exposure to vector bites in dry and rainy seasons using mathematical models. We estimated the protective efficacy of LLINs and characterised where (indoors vs. outdoors) and when both LLIN users and non-users were exposed to vector bites.ResultsThe percentage of the population who declared sleeping under a LLIN the previous night was very high regardless of the season, with an average LLIN use ranging from 92.43% to 99.89%. The use of LLIN provided > 80% protection against exposure to vector bites. The proportion of exposure for LLIN users was 29-57% after 05:00 and 0.05-12 % before 20:00. More than 80% of exposure occurred indoors for LLIN users and the estimate reached 90% for children under five years old in the dry cold season.ConclusionsThis study supports the current use of LLIN as a primary malaria vector control tool. It also emphasises the need to complement LLIN with indoor-implemented measures such as indoor residual spraying (IRS) and/or house improvement to effectively combat malaria in the rural area of Diébougou. Furthermore, malaria elimination programmes would also require strategies that target outdoor biting vectors to be successful in the area.


2020 ◽  
Author(s):  
Corine Ngufor ◽  
Renaud Govoetchan ◽  
Augustin Fongnikin ◽  
Estelle Vigninou ◽  
Thomas Syme ◽  
...  

AbstractThe rotational use of insecticides with different modes of action for indoor residual spraying (IRS) is recommended for improving malaria vector control and managing insecticide resistance. A more diversified portfolio of IRS insecticides is required; insecticides with new chemistries which can provide improved and prolonged control of insecticide-resistant vector populations are urgently needed. Broflanilide is a newly discovered insecticide being considered for malaria vector control. We investigated the efficacy of a wettable powder (WP) formulation of broflanilide (VECTRON™ T500) for IRS on mud and cement wall substrates in WHO laboratory and experimental hut studies against pyrethroid-resistant malaria vectors in Benin, in comparison with pirimiphos-methyl CS (Actellic® 300CS). There was no evidence of cross-resistance to pyrethroids and broflanilide in CDC bottle bioassays. In laboratory cone bioassays, mortality of susceptible and pyrethroid-resistant A. gambiae s.l. with broflanilide WP treated substrates was >80% for 6-14 months. At application rates of 100mg/m2 and 150 mg/m2, mortality of wild pyrethroid-resistant A. gambiae s.l. entering treated experimental huts in Covè, Benin was 57%-66% with broflanilide WP and did not differ significantly from pirimiphos-methyl CS (57-66% vs. 56%, P>0.05). Mosquito mortality did not differ between the two application rates and local wall substrate-types tested (P>0.05). Throughout the 6-month hut trial, monthly wall cone bioassay mortality on broflanilide WP treated hut walls remained >80% for both susceptible and resistant strains of A. gambiae s.l.. Broflanilide shows potential to significantly improve the control of malaria transmitted by pyrethroid-resistant mosquito vectors and would thus be a crucial addition to the current portfolio of IRS insecticides.One Sentence SummaryVECTRON™ T500, a new wettable powder formulation of broflanilide developed for indoor residual spraying, showed high and prolonged activity against wild pyrethroid-resistant malaria vectors, on local wall substrates, in laboratory bioassays and experimental household settings in Benin.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Elodie Ekoka ◽  
Surina Maharaj ◽  
Luisa Nardini ◽  
Yael Dahan-Moss ◽  
Lizette L. Koekemoer

AbstractWith the rapid development and spread of resistance to insecticides among anopheline malaria vectors, the efficacy of current World Health Organization (WHO)-approved insecticides targeting these vectors is under threat. This has led to the development of novel interventions, including improved and enhanced insecticide formulations with new targets or synergists or with added sterilants and/or antimalarials, among others. To date, several studies in mosquitoes have revealed that the 20-hydroxyecdysone (20E) signaling pathway regulates both vector abundance and competence, two parameters that influence malaria transmission. Therefore, insecticides which target 20E signaling (e.g. methoxyfenozide and halofenozide) may be an asset for malaria vector control. While such insecticides are already commercially available for lepidopteran and coleopteran pests, they still need to be approved by the WHO for malaria vector control programs. Until recently, chemicals targeting 20E signaling were considered to be insect growth regulators, and their effect was mostly studied against immature mosquito stages. However, in the last few years, promising results have been obtained by applying methoxyfenozide or halofenozide (two compounds that boost 20E signaling) to Anopheles populations at different phases of their life-cycle. In addition, preliminary studies suggest that methoxyfenozide resistance is unstable, causing the insects substantial fitness costs, thereby potentially circumventing one of the biggest challenges faced by current vector control efforts. In this review, we first describe the 20E signaling pathway in mosquitoes and then summarize the mechanisms whereby 20E signaling regulates the physiological processes associated with vector competence and vector abundance. Finally, we discuss the potential of using chemicals targeting 20E signaling to control malaria vectors.


F1000Research ◽  
2022 ◽  
Vol 10 ◽  
pp. 200
Author(s):  
Dewi Susanna ◽  
Dian Pratiwi

Background: The application of insecticides for malaria vector control has led to a global problem, which is the current trend of increased resistance against these chemicals. This study aimed to review the insecticide resistance status was previously determined in Asia and how to implement the necessary interventions. Moreover, the implications of resistance in malaria vector control in this region were studied. Methods: This systematic review was conducted using a predefined protocol based on PRISMA-retrieved articles from four science databases, namely ProQuest, Science Direct, EBSCO, and PubMed in the last ten years (2009 to 2019). The searching process utilized four main combinations of the following keywords: malaria, vector control, insecticide, and Asia. In ProQuest, malaria control, as well as an insecticide, were used as keywords. The following criteria were included in the filter, namely full text, the source of each article, scholarly journal, Asia, and publication date as in the last ten years. Results: There were 1408 articles retrieved during the initial search (ProQuest=722, Science Direct=267, EBSCO=50, PubMed=285, and Scopus=84). During the screening, 27 articles were excluded because of duplication, 1361 based on title and abstract incompatibility with the inclusion criteria, and 20 due to content differences. In the final screening process, 15 articles were chosen to be analyzed. From the 15 articles, it is known that there was organochlorine (DDT), organophosphate (malathion), and pyrethroids resistance in several Anopheles species with a less than 80% mortality rate. Conclusion: This review found multiple resistance in several Anopheles includes resistance to pyrethroid. The reports of pyrethroid resistance were quite challenging because it is considered effective in the malaria vector control. Several countries in Asia are implementing an insecticide resistance management (IRM) strategy against malaria vectors following the Global Plan for IRM.


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