scholarly journals Evaluating insecticide resistance across African districts to aid malaria control decisions

2020 ◽  
Vol 117 (36) ◽  
pp. 22042-22050 ◽  
Author(s):  
Catherine L. Moyes ◽  
Duncan K. Athinya ◽  
Tara Seethaler ◽  
Katherine E. Battle ◽  
Marianne Sinka ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Pyrethroid Resistance ◽  
Resistance Mechanisms ◽  
World Health ◽  
Malaria Vector Control ◽  
Ensemble Model ◽  
Metabolic Resistance ◽  
The World ◽  
Susceptibility Tests ◽  
Health Organization

Malaria vector control may be compromised by resistance to insecticides in vector populations. Actions to mitigate against resistance rely on surveillance using standard susceptibility tests, but there are large gaps in the monitoring data across Africa. Using a published geostatistical ensemble model, we have generated maps that bridge these gaps and consider the likelihood that resistance exceeds recommended thresholds. Our results show that this model provides more accurate next-year predictions than two simpler approaches. We have used the model to generate district-level maps for the probability that pyrethroid resistance inAnopheles gambiaes.l. exceeds the World Health Organization thresholds for susceptibility and confirmed resistance. In addition, we have mapped the three criteria for the deployment of piperonyl butoxide-treated nets that mitigate against the effects of metabolic resistance to pyrethroids. This includes a critical review of the evidence for presence of cytochrome P450-mediated metabolic resistance mechanisms across Africa. The maps for pyrethroid resistance are available on the IR Mapper website, where they can be viewed alongside the latest survey data.

scholarly journals Mapping insecticide resistance in mosquitoes to aid malaria control

2020 ◽  
Author(s):  
Catherine L. Moyes ◽  
Duncan Kobia Athinya ◽  
Tara Seethaler ◽  
Katherine Battle ◽  
Marianne Sinka ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Malaria Control ◽  
Pyrethroid Resistance ◽  
Resistance Management ◽  
Resistance Mechanisms ◽  
World Health ◽  
Malaria Vector Control ◽  
Metabolic Resistance ◽  
Insecticide Resistance Management ◽  
Health Organization

AbstractMalaria vector control may be compromised by resistance to insecticides in vector populations. Actions to mitigate against resistance rely on surveillance using standard susceptibility tests, but there are large gaps in the monitoring data. Using a published geostatistical ensemble model, we have generated maps that bridge these gaps and consider the likelihood that resistance exceeds recommended thresholds. Our results show that this model provides more accurate next-year predictions than two simpler approaches. We have used the model to generate district-level maps for the probability that pyrethroid resistance in Anopheles gambiae s.l. exceeds the World Health Organization (WHO) thresholds for susceptibility and confirmed resistance. In addition, we have mapped the three criteria for the deployment of piperonyl butoxide-treated nets that mitigate against the effects of metabolic resistance to pyrethroids. This includes a critical review of the evidence for presence of cytochrome P450-mediated metabolic resistance mechanisms across Africa. The maps for pyrethroid resistance are available on the IR Mapper website where they can be viewed alongside the latest survey data.Significance StatementMalaria control in Africa largely relies on the use of insecticides to prevent mosquitoes from transmitting the malaria parasite to humans, however, these mosquitoes have evolved resistance to these insecticides. To manage this threat to malaria control, it is vital that we map locations where the prevalence of resistance exceeds thresholds defined by insecticide resistance management plans. A geospatial model and data from Africa are used to predict locations where thresholds of resistance linked to specific recommended actions are exceeded. This model is shown to provide more accurate next-year predictions than two simpler approaches. The model is used to generate maps that aid insecticide resistance management planning and that allow targeted deployment of interventions that counter specific mechanisms of resistance.

scholarly journals Potential Metabolic Resistance Mechanisms to Ivermectin in Anopheles Gambiae: A Synergist Bioassay Study

2020 ◽  
Author(s):  
Patricia Nicolas ◽  
Caroline Kiuru ◽  
Martin Wagah ◽  
Martha Muturi ◽  
Urs Duthaler ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Anopheles Gambiae ◽  
Control Strategies ◽  
Resistance Mechanisms ◽  
World Health ◽  
Malaria Vectors ◽  
Malaria Vector Control ◽  
Cytochrome P450 Enzymes ◽  
Metabolic Resistance ◽  
Active Efflux

Abstract Background Despite remarkable success obtained with current malaria vector control strategies in the last 15 years, additional innovative measures will be needed to achieve the ambitious goals set for 2030 by the World Health Organization (WHO). New tools will need to address insecticide resistance and residual transmission as key challenges. Endectocides such as ivermectin are drugs that kill mosquitoes which feed on treated subjects. Mass administration of ivermectin can effectively target outdoor and early biting vectors, complementing the still effective conventional tools. Although this approach has garnered attention, development of ivermectin resistance is a potential pitfall. Herein, we evaluate the potential role of xenobiotic pumps and cytochrome P450 enzymes in protecting mosquitoes against ivermectin by active efflux and metabolic detoxification, respectively. Methods We determined the lethal-concentration 50 for ivermectin in colonized Anopheles gambiae, then we used chemical inhibitors and inducers of xenobiotic pumps and cytochrome P450 enzymes in combination with ivermectin to probe the mechanism of ivermectin detoxification. Results Dual inhibition of xenobiotic pumps and cytochromes have a synergistic effect with ivermectin, greatly increasing mosquito mortality. Inhibition of xenobiotic pumps alone had no effect on ivermectin-induced mortality. Induction of xenobiotic pumps and cytochromes may confer partial protection from ivermectin.Conclusion there is a clear pathway for development of ivermectin resistance in malaria vectors. Detoxification mechanisms mediated by cytochrome P450 enzymes are more important than xenobiotic pumps in protecting mosquitoes against ivermectin.

scholarly journals Potential metabolic resistance mechanisms to ivermectin in Anopheles gambiae: a synergist bioassay study

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Patricia Nicolas ◽  
Caroline Kiuru ◽  
Martin G. Wagah ◽  
Martha Muturi ◽  
Urs Duthaler ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Anopheles Gambiae ◽  
Control Strategies ◽  
Resistance Mechanisms ◽  
World Health ◽  
Malaria Vectors ◽  
Malaria Vector Control ◽  
Cytochrome P450 Enzymes ◽  
Metabolic Resistance ◽  
Active Efflux

Abstract Background Despite remarkable success obtained with current malaria vector control strategies in the last 15 years, additional innovative measures will be needed to achieve the ambitious goals for malaria control set for 2030 by the World Health Organization (WHO). New tools will need to address insecticide resistance and residual transmission as key challenges. Endectocides such as ivermectin are drugs that kill mosquitoes which feed on treated subjects. Mass administration of ivermectin can effectively target outdoor and early biting vectors, complementing the still effective conventional tools. Although this approach has garnered attention, development of ivermectin resistance is a potential pitfall. Herein, we evaluate the potential role of xenobiotic pumps and cytochrome P450 enzymes in protecting mosquitoes against ivermectin by active efflux and metabolic detoxification, respectively. Methods We determined the lethal concentration 50 for ivermectin in colonized Anopheles gambiae; then we used chemical inhibitors and inducers of xenobiotic pumps and cytochrome P450 enzymes in combination with ivermectin to probe the mechanism of ivermectin detoxification. Results Dual inhibition of xenobiotic pumps and cytochromes was found to have a synergistic effect with ivermectin, greatly increasing mosquito mortality. Inhibition of xenobiotic pumps alone had no effect on ivermectin-induced mortality. Induction of xenobiotic pumps and cytochromes may confer partial protection from ivermectin. Conclusion There is a clear pathway for development of ivermectin resistance in malaria vectors. Detoxification mechanisms mediated by cytochrome P450 enzymes are more important than xenobiotic pumps in protecting mosquitoes against ivermectin.

scholarly journals EFEKTIFITAS PENGGUNAAN KELAMBU BERINSEKTISIDA (LLINs) TERHADAP KASUS MALARIA (Studi Di Desa Ngreco Kecamatan Tegalombo Kabupaten Pacitan Tahun 2016)

2017 ◽  
Vol 15 (1) ◽  
Author(s):  
Rizka Ilmawati ◽  
Sri Mardoyo ◽  
Suroso Bambang Eko Warno
Keyword(s):  
Vector Control ◽  
Malaria Vector ◽  
World Health ◽  
Malaria Vector Control ◽  
Insecticide Treated Nets ◽  
Mosquito Net ◽  
Control Effort ◽  
The World ◽  
Quasi Experimental ◽  
Health Organization

ABSTRACTMalaria is a contagious disease that still becomes wide health problem in the world, including Indonesia.In 2014, API of Pacitan was the highest in East Java with 75 patients suffered from malaria. One of the endemicvillage in Pacitan is Ngreco village. Malaria vector control effort undertaken in the village is the use of insecticidetreatedbed nets, as recommended by the World Health Organization (WHO). The use of insecticide-treated netseffectively prevent transmission of malaria when supported with good care to insecticide-treated nets.This study aims to determine the effectiveness of insecticide-treated nets used by Ngreco Villagecommunity as malaria vector control to the decline in malaria cases. This is a quasi-experimental research. Thedata were collected through interview and sampling. The research sample was 29 homes for interviews and 4insecticide-treated nets used by the community for Bio-assay Test.The results of this study shows a decrease in new case of malaria in 2007-2010 from 23 new cases into2 new cases in 2011 to 2015. The results of efficacy test conducted on four samples of net used by thecommunity showed that net with 30 months of use (effectiveness <80%) are no longer effective to be used as avector control of malaria, while net with 12 months of use (effectiveness> 80%) is still effective to be used asmalaria vector control.The society should pay more attention on how to laundry the net that it is durable as malaria vectorcontrol. The health center needs to conduct controlling of mosquito nets routinely to find out whether the netsare still effective that replacement or dyeing of the of net can be performed.Keywords: Insecticidal mosquito net, effectiveness, malaria

scholarly journals Assessing cross-resistance within the pyrethroids in terms of their interactions with key cytochrome P450 enzymes and resistance in vector populations

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
C. L. Moyes ◽  
R. S. Lees ◽  
C. Yunta ◽  
K. J. Walker ◽  
K. Hemmings ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Binding Affinity ◽  
Malaria Vector ◽  
Pyrethroid Resistance ◽  
Resistance Mechanisms ◽  
Cross Resistance ◽  
Type I ◽  
Cytochrome P450 Enzymes ◽  
Metabolic Resistance ◽  
The Common

Abstract Background It is important to understand whether the potential impact of pyrethroid resistance on malaria control can be mitigated by switching between different pyrethroids or whether cross-resistance within this insecticide class precludes this approach. Methods Here we assess the relationships among pyrethroids in terms of their binding affinity to, and depletion by, key cytochrome P450 enzymes (hereafter P450s) that are known to confer metabolic pyrethroid resistance in Anopheles gambiae (s.l.) and An. funestus, in order to identify which pyrethroids may diverge from the others in their vulnerability to resistance. We then investigate whether these same pyrethroids also diverge from the others in terms of resistance in vector populations. Results We found that the type I and II pyrethroids permethrin and deltamethrin, respectively, are closely related in terms of binding affinity to key P450s, depletion by P450s and resistance within vector populations. Bifenthrin, which lacks the common structural moiety of most pyrethroids, diverged from the other pyrethroids tested in terms of both binding affinity to key P450s and depletion by P450s, but resistance to bifenthrin has rarely been tested in vector populations and was not analysed here. Etofenprox, which also lacks the common structural moiety of most pyrethroids, diverged from the more commonly deployed pyrethroids in terms of binding affinity to key P450s and resistance in vector populations, but did not diverge from these pyrethroids in terms of depletion by the P450s. The analysis of depletion by the P450s indicated that etofenprox may be more vulnerable to metabolic resistance mechanisms in vector populations. In addition, greater resistance to etofenprox was found across Aedes aegypti populations, but greater resistance to this compound was not found in any of the malaria vector species analysed. The results for pyrethroid depletion by anopheline P450s in the laboratory were largely not repeated in the findings for resistance in malaria vector populations. Conclusion Importantly, the prevalence of resistance to the pyrethroids α-cypermethrin, cyfluthrin, deltamethrin, λ-cyhalothrin and permethrin was correlated across malaria vector populations, and switching between these compounds as a tool to mitigate against pyrethroid resistance is not advised without strong evidence supporting a true difference in resistance.

scholarly journals Open source 3D printable replacement parts for the WHO insecticide susceptibility bioassay system

2019 ◽  
Author(s):  
Sean Tomlinson ◽  
Henrietta C. Yates ◽  
Ambrose Oruni ◽  
Harun Njoroge ◽  
David Weetman ◽  
...  
Keyword(s):  
Prolonged Exposure ◽  
World Health ◽  
Adult Mosquito ◽  
Malaria Vector Control ◽  
3D Printer ◽  
Development Of Resistance ◽  
Significant Difference ◽  
The World ◽  
Timely Fashion ◽  
Health Organization

BackgroundMalaria vector control and research rely heavily on monitoring mosquito populations for the development of resistance to public health insecticides. One standard method for determining susceptibility in adult mosquito populations is the World Health Organization test (WHO bioassay). The WHO bioassay kit consists of several acrylic pieces that are assembled into a unit. Parts of the kit commonly break, reducing the capacity of insectaries to carry out resistance profiling. Since there is at present only a single supplier for the test kits, replacement parts can be hard to procure in a timely fashion. Here, we present 3D printable versions for all pieces of the WHO bioassay kit.ResultsUsing widely available polylactic acid (PLA) filament as a printing material, we were able to design and print functional replacements for each piece of the WHO bioassay kit. We note no significant difference in mortality results obtained from PLA printed tubes and WHO acrylic tubes. Additionally, we observed no degradation of PLA in response to prolonged exposure times of commonly used cleaning solutions.ConclusionsOur designs can be used to produce replacement parts for the WHO bioassay kit in any facility with a 3D printer, which are becoming increasingly widespread. 3D printing technologies can affordably and rapidly address equipment shortages and be used to develop bespoke equipment in laboratories.

Erstes Instrument zur standardisierten Erfassung der Teilhabe Behinderter

2017 ◽  
Vol 79 (07) ◽  
pp. 526-527
Keyword(s):  
World Health Organization ◽  
World Health ◽  
The World ◽  
Health Organization ◽  
Menschen Mit Behinderung

Coenen M et al. [Recommendation for the collection and analysis of data on participation and disability from the perspective of the World Health Organization]. Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz 2016; 59: 1060–1067 Um eine gleichberechtigte Teilhabe an der Gesellschaft von Menschen mit Behinderung zu ermöglichen, werden zunächst Daten zu vorhandenen Einschränkungen gebraucht. Erst wenn diese detailliert erhoben wurden, können Konzepte zur Beseitigung von Problemen entwickelt werden. Ein standardisiertes Erhebungsinstrument für alle Aspekte der Funktionsfähigkeit fehlte jedoch bisher.

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