Exposure of Gambian children to Anopheles gambiae malaria vectors in an irrigated rice production area

Cultivation of rice in Ethiopia is generally a recent phenomenon it was started first at Fogera and Gambella Plains in the early 1970’s, which is preceded by its utilization as a food crop. Hence the present review was to review on adoption, Trend, potential, and constraints of rice production to livelihood in Ethiopia. Although rice was introduced to the country very recently, it has proven to be a crop that can assure food security in Ethiopia. It is reported that the potential rice production area in Ethiopia is estimated to be about thirty million hectares. Since 2006, Ethiopian rice production trends show increases in both area and productivity. Considering the importance and potential of the crop, it has been recognized by the Government as “the new millennium crop of Ethiopia” to attain food security. Rice has become a commodity of strategic significance across many parts of Ethiopia for domestic consumption as well as export market for economic development. Due to the introduction of upland and irrigated rice varieties in the country, rice farming has increased from time to time. There has been twelve upland/lowland NERICAs and Sativa-type, and three irrigated rice varieties released in Ethiopia from 1999 up to 2007. However, Ethiopian rice sector still faces remaining challenges such as high competition with imported rice, poor infrastructure, insufficient mechanization and post-harvest processing technologies, lack of skilled manpower and research facilities, poor marketing infrastructure, and channels. Therefore, building the capacity of the research community, experts, smallholder farmers and the private sector is necessary not only to further increase production but also to improve the quality of rice products through better post-harvest handling and processing.

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Insecticide resistance status of malaria vectors Anopheles gambiae (s.l.) of southwest Burkina Faso and residual efficacy of indoor residual spraying with microencapsulated pirimiphos-methyl insecticide

Parasites & Vectors ◽

10.1186/s13071-020-04563-8 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Dieudonné Diloma Soma ◽

Barnabas Zogo ◽

Domonbabele François de Sales Hien ◽

Aristide Sawdetuo Hien ◽

Didier Alexandre Kaboré ◽

...

Keyword(s):

Insecticide Resistance ◽

Burkina Faso ◽

Anopheles Gambiae ◽

Local Population ◽

Residual Activity ◽

Indoor Residual Spraying ◽

Susceptible Strain ◽

Malaria Vectors ◽

Pirimiphos Methyl ◽

Residual Efficacy

Abstract Background The rapid spread of insecticide resistance in malaria vectors and the rebound in malaria cases observed recently in some endemic areas underscore the urgent need to evaluate and deploy new effective control interventions. A randomized control trial (RCT) was conducted with the aim to investigate the benefit of deploying complementary strategies, including indoor residual spraying (IRS) with pirimiphos-methyl in addition to long-lasting insecticidal nets (LLINs) in Diébougou, southwest Burkina Faso. Methods We measured the susceptibility of the Anopheles gambiae (s.l.) population from Diébougou to conventional insecticides. We further monitored the efficacy and residual activity of pirimiphos-methyl on both cement and mud walls using a laboratory susceptible strain (Kisumu) and the local An. gambiae (s.l.) population. Results An. gambiae (s.l.) from Diébougou was resistant to DDT, pyrethroids (deltamethrin, permethrin and alphacypermethrin) and bendiocarb but showed susceptibility to organophosphates (pirimiphos-methyl and chlorpyrimiphos-methyl). A mixed-effect generalized linear model predicted that pirimiphos-methyl applied on cement or mud walls was effective for 210 days against the laboratory susceptible strain and 247 days against the local population. The residual efficacy of pirimiphos-methyl against the local population on walls made of mud was similar to that of cement (OR = 0.792, [0.55–1.12], Tukey’s test p-value = 0.19). Conclusions If data on malaria transmission and malaria cases (as measured trough the RCT) are consistent with data on residual activity of pirimiphos-methyl regardless of the type of wall, one round of IRS with pirimiphos-methyl would have the potential to control malaria in a context of multi-resistant An. gambiae (s.l.) for at least 7 months.

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Anopheles gambiae Genome Conservation as a Resource for Rational Gene Drive Target Site Selection

Insects ◽

10.3390/insects12020097 ◽

2021 ◽

Vol 12 (2) ◽

pp. 97

Author(s):

Nace Kranjc ◽

Andrea Crisanti ◽

Tony Nolan ◽

Federica Bernardini

Keyword(s):

Anopheles Gambiae ◽

Data Storage ◽

Genomic Variation ◽

Malaria Vectors ◽

Anopheles Coluzzii ◽

Structural Constraints ◽

Gene Drive ◽

Genetic Traits ◽

A Genome ◽

Insight Into

The increase in molecular tools for the genetic engineering of insect pests and disease vectors, such as Anopheles mosquitoes that transmit malaria, has led to an unprecedented investigation of the genomic landscape of these organisms. The understanding of genome variability in wild mosquito populations is of primary importance for vector control strategies. This is particularly the case for gene drive systems, which look to introduce genetic traits into a population by targeting specific genomic regions. Gene drive targets with functional or structural constraints are highly desirable as they are less likely to tolerate mutations that prevent targeting by the gene drive and consequent failure of the technology. In this study we describe a bioinformatic pipeline that allows the analysis of whole genome data for the identification of highly conserved regions that can point at potential functional or structural constraints. The analysis was conducted across the genomes of 22 insect species separated by more than hundred million years of evolution and includes the observed genomic variation within field caught samples of Anopheles gambiae and Anopheles coluzzii, the two most dominant malaria vectors. This study offers insight into the level of conservation at a genome-wide scale as well as at per base-pair resolution. The results of this analysis are gathered in a data storage system that allows for flexible extraction and bioinformatic manipulation. Furthermore, it represents a valuable resource that could provide insight into population structure and dynamics of the species in the complex and benefit the development and implementation of genetic strategies to tackle malaria.

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The regulatory genome of the malaria vector Anopheles gambiae: integrating chromatin accessibility and gene expression

NAR Genomics and Bioinformatics ◽

10.1093/nargab/lqaa113 ◽

2021 ◽

Vol 3 (1) ◽

Author(s):

José L Ruiz ◽

Lisa C Ranford-Cartwright ◽

Elena Gómez-Díaz

Keyword(s):

Gene Expression ◽

Transcriptional Regulation ◽

Anopheles Gambiae ◽

Mosquito Control ◽

Regulatory Elements ◽

Chromatin Accessibility ◽

Malaria Vectors ◽

Specific Gene ◽

Mosquito Vector ◽

Human Malaria

Abstract Anopheles gambiae mosquitoes are primary human malaria vectors, but we know very little about their mechanisms of transcriptional regulation. We profiled chromatin accessibility by the assay for transposase-accessible chromatin by sequencing (ATAC-seq) in laboratory-reared A. gambiae mosquitoes experimentally infected with the human malaria parasite Plasmodium falciparum. By integrating ATAC-seq, RNA-seq and ChIP-seq data, we showed a positive correlation between accessibility at promoters and introns, gene expression and active histone marks. By comparing expression and chromatin structure patterns in different tissues, we were able to infer cis-regulatory elements controlling tissue-specific gene expression and to predict the in vivo binding sites of relevant transcription factors. The ATAC-seq assay also allowed the precise mapping of active regulatory regions, including novel transcription start sites and enhancers that were annotated to mosquito immune-related genes. Not only is this study important for advancing our understanding of mechanisms of transcriptional regulation in the mosquito vector of human malaria, but the information we produced also has great potential for developing new mosquito-control and anti-malaria strategies.

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Human biting rhythm of Anopheles gambiae Giles, 1902 (Diptera: Culicidae) and sleeping behaviour of pregnant women in a lagoon area in Southern Benin

BMC Research Notes ◽

10.1186/s13104-021-05615-7 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Armel Djènontin ◽

Aziz Bouraima ◽

Christophe Soares ◽

Seun Egbinola ◽

Gilles Cottrell

Keyword(s):

Plasmodium Falciparum ◽

Pregnant Women ◽

Anopheles Gambiae ◽

Early Morning ◽

Allelic Frequency ◽

Malaria Vectors ◽

Mosquito Nets ◽

Anopheles Gambiae Giles ◽

Almost All ◽

Southern Benin

Abstract Objective In the framework of EVALMOUS study aiming to assess the use and effectiveness of mosquito nets by pregnant women and other members of their household in a lagoon area in southern Benin, the behaviour of pregnant women relative to the time they go to bed using the net were recorded. Malaria vectors biting rhythm, Plasmodium falciparum infection and insecticide resistance genes in malaria vectors were also determined. Results Overall, 3848 females of Anopheles gambiae s. l were collected and 280 pregnant women responded to the survey. Almost all Anopheles gambiae s. l. tested were Anopheles coluzzi Coetzee and Wilkerson 2013 (Diptera: Culicidae). The CSP index in malaria vector was 1.85% and the allelic frequency of kdr gene was 74.4%. Around 90% of bites and Plasmodium falciparum Welch, 1897 (Haemosporida: Plasmodiidae) transmission occurred between 10 p.m. and 6 a.m., which coincides with the period when more than 80% of pregnant women were under bednet. Despite a slight early evening and early morning biting activity of malaria vectors in the study area, the good use of nets might remain a useful protection tool against mosquito biting and malaria transmission.

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Impact of Herbicides on Non-Target Organisms in Sustainable Irrigated Rice Production Systems: State of Knowledge and Future Prospects

Herbicides and Environment ◽

10.5772/13568 ◽

2011 ◽

Author(s):

Victor Galhano ◽

Laranjo Gomes ◽

Fernndez-valientec Eduardo ◽

Romeu Videira ◽

Francisco Peixoto

Keyword(s):

Production Systems ◽

Rice Production ◽

Future Prospects ◽

Irrigated Rice

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Bioefficacy of local Lantana camara (Verberneae) plant extracts against the 3rd instar larva and adult stages of Anopheles gambiae senso lato (Giles).

Journal of Medical Research and Health Sciences ◽

10.15520/jmrhs.v3i12.214 ◽

2020 ◽

Vol 3 (12) ◽

pp. 1120-1129

Author(s):

Wenceslas Yana ◽

Enda Corinna Andu ◽

Katamssadan Haman Tofel ◽

Abe Henri

Keyword(s):

Anopheles Gambiae ◽

Aqueous Extract ◽

Exposure Time ◽

Larval Mortality ◽

Acetone Extract ◽

Lantana Camara ◽

Hexane Extract ◽

Lethal Concentration ◽

Malaria Vectors ◽

Malaria Vector Control

Resistance of malaria vectors to synthetic chemicals with high operational cost and environmental pollution has been a great challenge to scientists. Alternative approaches such as the use of natural plant products which are environmentally friendly are put in place to control malaria vectors. This study was focused on testing the effectiveness of three solvent extracts of Lantana camara on the 3rd instar larvae and adults of Anopheles gambiae s. l. These extracts were obtained by maceration. Bioassays test were carried out by WHO’s method for determination of larvicidal and adulticidal efficacy. The results show that, larval mortality increased significantly with the concentration and exposure time. Lethal concentrations 50 (LC50) and 95 (LC95) after 24 hours of larvae exposure time are respectively 0.31 g/mL and 1.53 g/mL while within 48 h they are 0.27 g/mL and 0.79 g/mL for hexane extract; 1.45 g/mL and 2.0 g/mL (24 h exposure), 0.84 g/mL and 1.55 g/mL (48 h exposure) for acetone extract; 1.96 g/mL and no lethal concentration causing 95% mortality was determined; 0.40 g/mL and 2.20 g/mL (48 h) for aqueous extract. The efficacy of hexane and aqueous extract on the adult knock down and mortality were not significant even with the increasing extract concentrations and exposure time whereas with acetone extract, the adult LC50 after 24 h was 2.4 g/mL but with 95% mortality lethal concentration was not determined. According to the results, hexane extract showed high larvicidal efficacy of An. gambiae and acetone extract showed significant adult mortality. Those two extracts of L. camara can be used to fight against An. gambiae as alternative malaria vector control to replace conventional insecticides.

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Monitoring of the irrigated rice production dynamic in the Kazalinsk region, Kazakhstan, from 1984-2017

Central Asian Journal of Water Research ◽

10.29258/cajwr/2019-r1.v5-2/20-43.eng ◽

2019 ◽

Vol 5 (2) ◽

pp. 20-43

Author(s):

Olga Degtyareva ◽

◽

Nadiya Muratova ◽

Vitaly Salnikov ◽

Michael Thiel ◽

...

Keyword(s):

Rice Production ◽

Irrigated Rice ◽

Production Dynamic

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Phenotypic Insecticide Resistance in Anopheles gambiae (Diptera: Culicidae): Specific Characterization of Underlying Resistance Mechanisms Still Matters

Journal of Medical Entomology ◽

10.1093/jme/tjaa195 ◽

2020 ◽

Author(s):

Adandé A Medjigbodo ◽

Luc S Djogbenou ◽

Aubin A Koumba ◽

Laurette Djossou ◽

Athanase Badolo ◽

...

Keyword(s):

Insecticide Resistance ◽

Anopheles Gambiae ◽

Resistance Mechanisms ◽

Malaria Vectors ◽

Effective Control ◽

Anopheles Coluzzii ◽

Anopheles Gambiae S.S ◽

Diagnostic Dose ◽

Pirimiphos Methyl ◽

Old Adult

Abstract An effective control of malaria vectors requires an extensive knowledge of mechanisms underlying the resistance-phenotypes developed by these vectors against insecticides. We investigated Anopheles gambiae mosquitoes from Benin and Togo for their intensity of insecticide resistance and we discussed the involvement of genotyped mechanisms in the resistance-phenotypes observed. Three- to five-day-old adult mosquitoes emerged from field and laboratory An. gambiae larvae were assayed using WHO tube intensity tests against various doses of deltamethrin: 1× (0.05%); 2× (0.1%); 5× (0.25%); 7.5× (0.375%) and those of pirimiphos-methyl: 0.5× (0.125%); 1× (0.25%). Members of An. gambiae complex were screened in field populations using polymerase chain reaction (PCR) assays. The presence of kdrR(1014F/1014S) and ace-1R(119S) mutations was also investigated using TaqMan and PCR-RFLP techniques, respectively. Anopheles gambiae from field were very resistant to deltamethrin, whereas KisKdr and AcerKdrKis strains displayed 100% mortality rates at 2× the diagnostic dose. In contrast, the field mosquitoes displayed a low resistance-intensity against 1× the diagnostic dose of pirimiphos-methyl, whereas AcerKis and AcerKdrKis strains showed susceptibility at 0.5× the diagnostic dose. Anopheles gambiae s.s., Anopheles coluzzii, and Anopheles arabiensis were identified. Allelic frequencies of kdrR (1014F) and ace-1R (119S) mutations in the field populations varied from 0.65 to 1 and 0 to 0.84, respectively. The field An. gambiae displayed high-resistance levels against deltamethrin and pirimiphos-methyl when compared with those of the laboratory An. gambiae-resistant strains. These results exhibit the complexity of underlying insecticide resistance mechanisms in these field malaria vectors.

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