scholarly journals Bio-efficacy and Wash-fastness of a Lamda-cyhalothrin Long-lasting Insecticide Treatment Kit (ICON® Maxx) Against Mosquitoes on Various Polymer Materials

2021 ◽  
Author(s):  
Patrick Tungu ◽  
Wema Sudi ◽  
Harparkash Kaur ◽  
Stephen Magesa ◽  
Mark Rowland
Keyword(s):  
Malaria Prevention ◽  
Home Treatment ◽  
Polymer Materials ◽  
World Health ◽  
Insecticide Treated Nets ◽  
Pyrethroid Insecticides ◽  
Wash Fastness ◽  
Lambda Cyhalothrin ◽  
Efficacy Criteria ◽  
Health Organization

Abstract BackgroundLong-lasting efficacy of insecticide treated nets is a balance between adhesion, retention and migration of insecticide to the surface of netting fibres. ICON® Maxx is a twin-sachet ‘home-treatment kit’ of pyrethroid plus binding agent, recommended by the World Health Organization for long-lasting, wash-fast treatment of polyester nets. While knitted polyester netting is widely used, fine woven polyethylene netting is increasingly available and nets made of cotton and nylon are common in Africa and Asia. It is important to investigate whether ICON Maxx is able to fulfill the WHO criteria of long-lasting treatment on a range of domestic fabrics to widen the scope for malaria protection.Method This study was a controlled comparison of the bio-efficacy and wash-fastness of lambda-cyhalothrin CS, with or without binder, on nets made of cotton, polyethylene, nylon, dyed and undyed polyester. Evaluation compared an array of bioassays, WHO cone and cylinder, median time to knockdown and WHO tunnel tests using Anopheles mosquitoes. Chemical assay revealed further insight. ResultsICON Maxx treated polyethylene and polyester netting met the WHO cone and tunnel test bio-efficacy criteria for LLIN after 20 standardized washes. Although nylon and cotton netting failed to meet the WHO cone and cylinder criteria, both materials passed the WHO tunnel test criterion of 80% mortality after 20 washes. All materials treated with standard lambda-cyhalothrin CS without binder failed to meet any of the WHO bio-efficacy criteria within 5 washes. ConclusionThe bio-efficacy of ICON Maxx against mosquitoes on netting washed up to 20 times demonstrated wash durability on a range of synthetic polymer and natural fibres: polyester, polyethylene, nylon and cotton. This raises the prospect of making the insecticide-binder kit into an effective approach for turning untreated nets, curtains, military clothing, blankets - and tents and tarpaulins as used in disasters and humanitarian emergencies - into effective malaria prevention products. It may provide a solution to the problem of reduced LLIN coverage between campaigns by converting commercially sourced untreated nets into LLINs through community or home treatment. It may also open the door to binding of non-pyrethroid insecticides to nets and textiles for control of pyrethroid resistant vectors.

scholarly journals Bio-efficacy and wash-fastness of a lambda-cyhalothrin long-lasting insecticide treatment kit (ICON® Maxx) against mosquitoes on various polymer materials

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Patrick K. Tungu ◽  
Wema S. Sudi ◽  
Harparkash Kaur ◽  
Stephen M. Magesa ◽  
Mark Rowland
Keyword(s):  
Malaria Prevention ◽  
Home Treatment ◽  
Polymer Materials ◽  
World Health ◽  
Insecticide Treated Nets ◽  
Pyrethroid Insecticides ◽  
Wash Fastness ◽  
Lambda Cyhalothrin ◽  
Efficacy Criteria ◽  
Health Organization

Abstract Background Long-lasting efficacy of insecticide-treated nets is a balance between adhesion, retention and migration of insecticide to the surface of netting fibres. ICON® Maxx is a twin-sachet ‘home-treatment kit’ of pyrethroid plus binding agent, recommended by the World Health Organization (WHO) for long-lasting, wash-fast treatment of polyester nets. While knitted polyester netting is widely used, fine woven polyethylene netting is increasingly available and nets made of cotton and nylon are common in Africa and Asia. It is important to investigate whether ICON Maxx is able to fulfill the WHO criteria of long-lasting treatment on a range of domestic fabrics to widen the scope for malaria protection. Methods This study was a controlled comparison of the bio-efficacy and wash-fastness of lambda-cyhalothrin CS, with or without binder, on nets made of cotton, polyethylene, nylon, dyed and undyed polyester. Evaluation compared an array of bioassays: WHO cone and cylinder, median time to knockdown and WHO tunnel tests using Anopheles mosquitoes. Chemical assay revealed further insight. Results ICON Maxx treated polyethylene and polyester netting met the WHO cone and tunnel test bio-efficacy criteria for LLIN after 20 standardized washes. Although nylon and cotton netting failed to meet the WHO cone and cylinder criteria, both materials passed the WHO tunnel test criterion of 80% mortality after 20 washes. All materials treated with standard lambda-cyhalothrin CS without binder failed to meet any of the WHO bio-efficacy criteria within 5 washes. Conclusion The bio-efficacy of ICON Maxx against mosquitoes on netting washed up to 20 times demonstrated wash durability on a range of synthetic polymer and natural fibres: polyester, polyethylene, nylon and cotton. This raises the prospect of making insecticide-binder kits into an effective approach for turning untreated nets, curtains, military clothing, blankets—and tents and tarpaulins as used in disasters and humanitarian emergencies—into effective malaria prevention products. It may provide a solution to the problem of reduced LLIN coverage between campaigns by converting commercially sourced untreated nets into LLINs through community or home treatment. It may also open the door to binding of non-pyrethroid insecticides to nets and textiles for control of pyrethroid resistant vectors.

scholarly journals The Efficacy of Vectron 20 WP, Etofenprox, for Indoor Residual Spraying in Areas of High Vector Resistance to Pyrethroids and Organochlorines in Zambia

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Emmanuel Chanda ◽  
Alister Kandyata ◽  
Javan Chanda ◽  
Faustina N. Phiri ◽  
Lucy Muzia ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
World Health Organization ◽  
Indoor Residual Spraying ◽  
Control Programme ◽  
World Health ◽  
Malaria Vectors ◽  
Insecticide Treated Nets ◽  
Lambda Cyhalothrin ◽  
Residual Efficacy ◽  
Health Organization

The selection of insecticide resistance in malaria vectors has the potential to compromise any insecticide-based vector control programme. To ensure that the insecticides used for indoor residual spraying and insecticide-treated nets in Zambia remain effective and their choice is evidence based, insecticide resistance surveillance and monitoring are essential. This study assessed and compared the residual efficacy of etofenprox (Vectron 20 WP), an ether pyrethroid, at 0.1 g/m2 with pyrethroids: bifenthrin (Bistar 10 WP) and lambda-cyhalothrin (Icon 10 CS) at 25 mg/m2 for indoor residual spraying. We also assessed the resistance status of etofenprox to local malaria vectors, An. funestus s.s and An. gambiae s.s, using World Health Organization standard protocols. The residual efficacy of Vectron 20 WP on cement, rendered walls of houses lasted for four months with 100% mortality. By the eighth month, the killing effect had reduced to 73.8% compared to 63.3% for bifenthrin and 77.0% for lambda-cyhalothrin. Susceptibility tests using standard World Health Organization assays on An. gambiae s.s showed susceptibility to etofenprox (0.1%) but some resistance was detected to Anopheles funestus s.s. The product is recommended as an ideal insecticide for indoor residual spraying for malaria control in Zambia as part of a resistance management programme in selected areas of the country.

Insecticide Resistance in Anopheles stephensi in Somali Region, Eastern Ethiopia

2020 ◽  
Author(s):  
Solomon Yared ◽  
Araya Gebressielasie ◽  
Lambodhar Damodaran ◽  
Victoria Bonnell ◽  
Karen Lopez ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Anopheles Stephensi ◽  
Mortality Rates ◽  
Resistance Mechanisms ◽  
World Health ◽  
Malaria Vectors ◽  
Eastern Ethiopia ◽  
Pyrethroid Insecticides ◽  
Pirimiphos Methyl ◽  
Health Organization

Abstract Background: The movement of malaria vectors into new areas is a growing concern in the efforts to control malaria. The recent report of Anopheles stephensi in eastern Ethiopia has raised the necessity to understand the insecticide resistance status of the vector in the region to better inform vector-based interventions. The aim of this study was to evaluate insecticide resistance in An. stephensi in eastern Ethiopia using two approaches: 1) World Health Organization (WHO) bioassay tests in An. stephensi and 2) genetic analysis of insecticide resistance genes in An. stephensi in eastern Ethiopia. Methods: Mosquito larvae and pupae were collected from Kebridehar. Insecticide susceptibility of An. stephensi was tested with malathion 5%, bendiocarb 0.1%, propoxur 0.1%, deltamethrin 0.05%, permethrin 0.75%, Pirimiphos-methyl 0.25% and DDT 4%, according to WHO standard protocols. Results: All An. stephensi samples were resistant to carbamates, with mortality rates 23% and 21% for bendiocarb and propoxur, respectively. Adult An. stephensi was also resistant to pyrethroid insecticides with mortality rates 67% for deltamethrin and 53% for permethrin. Resistance to DDT and malathion was detected in An. stephensi with mortality rates of 32% as well as An. stephensi was resistance to pirimiphos-methyl with mortality rates 14%. Analysis of the voltage gate sodium channel gene (vgsc) revealed the absence of kdr L1014 mutations. Conclusion: Overall, these findings support that An. stephensi is resistant to several classes of insecticides, most notably pyrethroids. However, the absence of the kdr L1014 gene may suggest non-target site resistance mechanisms. Continuous insecticide resistance monitoring should be carried out in the region to confirm the documented resistance and exploring mechanisms conferring resistance in An. stephensi in Ethiopia.

scholarly journals Reality of having bed nets at home, their status and pattern of using it at night among the population of Lakhantari Village Development Committee of Nepal

2018 ◽  
Vol 14 (1) ◽  
pp. 39-43
Author(s):  
Bijay Kumar Thapa ◽  
Kapil Kumar Pokharel ◽  
Nitendra Chaurasia ◽  
Alok Acharya ◽  
Rimu Mishra ◽  
...  
Keyword(s):  
Sample Size ◽  
Transmitted Disease ◽  
Cross Sectional Study ◽  
World Health ◽  
Bed Nets ◽  
Insecticide Treated Nets ◽  
Cross Sectional ◽  
Physical Integrity ◽  
Vector Borne ◽  
Health Organization

Background & Objectives:The use of insecticide treated nets has been advocated for the prevention of the vector borne transmitted disease (malaria) by the World Health Organization and UNICEF for more than a decade. In spite of this, there is no significant reduction in the transmission of the disease. Main objectives of study were to find out the real pattern of using it, to find out the physical integrity of the bed nets being used, and to prove the correlation in between the physical integrity of bed nets and the disease outcome. Torn bed nets with holes size more than 1.2 mm were considered as “holes” in this study.Materials & Methods:A community based cross- sectional study was carried out in Lakhantari VDC within the duration of two weeks. This VDC has been named recently as Gramthan Gaupalika one of State one.  Sample size of 384 was determined by the WHO sample size calculator. Face to face interview technique was used after taking consent from individual. Confidentiality was maintained. It was ethically approved by the IRC (Institutional Review Committee) of Nobel Medical College.Results:A total of 384 household were studied. Total household had bed nets but the physical integrity of bed nets was not intact. Almost 73% of the bed nets were torn having more than four holes in them. Nearly 94% of household used bed nets only for three to four days a week. Nearly half of the   Malaria was found among 22% and encephalitis in 17% of household. Conclusion:Use of bed nets do not prevent and provide guarantee from vector borne disease unless it is properly used. Torn bed nets are of almost no use unless people are using other preventive measures.

scholarly journals Antiplasmodial natural products: an update

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Nasir Tajuddeen ◽  
Fanie R. Van Heerden
Keyword(s):  
Natural Products ◽  
Relevant Literature ◽  
World Health ◽  
Effective Control ◽  
Insecticide Treated Nets ◽  
Scientific Databases ◽  
The World ◽  
Significant Public Health ◽  
Public Health Challenge ◽  
Health Organization

Abstract Background Malaria remains a significant public health challenge in regions of the world where it is endemic. An unprecedented decline in malaria incidences was recorded during the last decade due to the availability of effective control interventions, such as the deployment of artemisinin-based combination therapy and insecticide-treated nets. However, according to the World Health Organization, malaria is staging a comeback, in part due to the development of drug resistance. Therefore, there is an urgent need to discover new anti-malarial drugs. This article reviews the literature on natural products with antiplasmodial activity that was reported between 2010 and 2017. Methods Relevant literature was sourced by searching the major scientific databases, including Web of Science, ScienceDirect, Scopus, SciFinder, Pubmed, and Google Scholar, using appropriate keyword combinations. Results and Discussion A total of 1524 compounds from 397 relevant references, assayed against at least one strain of Plasmodium, were reported in the period under review. Out of these, 39% were described as new natural products, and 29% of the compounds had IC50 ≤ 3.0 µM against at least one strain of Plasmodium. Several of these compounds have the potential to be developed into viable anti-malarial drugs. Also, some of these compounds could play a role in malaria eradication by targeting gametocytes. However, the research into natural products with potential for blocking the transmission of malaria is still in its infancy stage and needs to be vigorously pursued.

scholarly journals Michael Elliott CBE. 30 September 1924 — 17 October 2007

2016 ◽  
Vol 62 ◽  
pp. 109-123 ◽  
Author(s):  
John Pickett
Keyword(s):  
Food Production ◽  
Insect Pests ◽  
World Health ◽  
Individual Contribution ◽  
Pyrethroid Insecticides ◽  
New Class ◽  
Structure Activity ◽  
The World ◽  
Health Organization ◽  
Global Food

Michael Elliott was the leader of work at Rothamsted that invented and subsequently commercially developed the pyrethroids, a new class of insecticides. Michael made probably the greatest individual contribution to the control of insect pests that not only constrain global food production but also affect the health of ourselves and our livestock. In one of the first pioneering structure–activity relationship studies, Michael led the multidisciplinary team that invented the major pyrethroid insecticides bioresmethrin, permethrin, cypermethrin and deltamethrin. In the 1980s these represented two-thirds of the global pyrethroid market; at that time pyrethroids captured more than 25% of the total insecticide market and were used on 33 million hectares of crops (Wirtz et al . 2009). In 2002 deltamethrin was the world's largest-selling pyrethroid, with annual sales worth $208 million (information from Cropnosis Ltd). In terms of human health, in 2009 it was estimated that pyrethroid-treated bednets significantly decreased the number of deaths due to malaria among children under five years of age by about one-fifth as well as reducing all incidents of malaria, and in 2011 the World Health Organization recommended its vastly expanded use. Reference Wirtz, K., Bala, S., Amann, A. & Elbert, A. 2009 A promise extended—future roles of pyrethroids in agriculture. Bayer CropSci. J. 62 , 145–158.

scholarly journals All Nets are Equal, But Some Nets are More Equal Than Others

2020 ◽  
Vol 31 (1) ◽  
pp. 2-4
Author(s):  
Mark Rowland
Keyword(s):  
Sub Saharan Africa ◽  
World Health ◽  
Insecticide Treated Nets ◽  
Comparative Performance ◽  
Malaria Burden ◽  
Test Product ◽  
Dramatic Decline ◽  
The World ◽  
Sub Saharan ◽  
Health Organization

Much of the dramatic decline in malaria in sub-Saharan Africa since 2000 is due to the massive investment in long-lasting insecticide treated nets (LLIN). According to the latest figures from the World Health Organization (WHO), over half of Africa's population now has access to LLIN, increasing from 33% in 2010 to 57% in 2019 (WHO 2019). In 2018 alone, 197 million LLINs were delivered to Africa by manufacturers. Despite this, LLIN coverage has improved only marginally since 2015. The malaria burden worldwide has fallen only slightly from an estimated 231 million cases of malaria in 2017 to 228 million in 2018, and is at a standstill in Africa. WHO policy is to assess candidate 2nd-in-class products for entomological efficacy only. Due to the significant variation in the specifications of the candidates, to generate the required assurance of comparative performance to 1st in class, WHO has designed a non-inferiority trial design to demonstrate whether each candidate 2nd-in-class test product is no worse in experimental hut trials.

scholarly journals Uptake of Intermittent Preventive Treatment for Malaria during Pregnancy with Sulphadoxine-Pyrimethamine in Malawi after adoption of updated World Health Organization policy: An Analysis of Demographic and Health Survey 2015-2016

2020 ◽  
Author(s):  
Steven Chifundo Azizi
Keyword(s):  
Health Survey ◽  
Intermittent Preventive Treatment ◽  
Preventive Treatment ◽  
Malaria Prevention ◽  
Demographic And Health Survey ◽  
World Health ◽  
Limited Effectiveness ◽  
Malaria During Pregnancy ◽  
Health Organization ◽  
Sulphadoxine Pyrimethamine

Abstract Background: Malawi adopted the 2012 updated Word Health Organization (WHO) Intermittent preventive treatment of malaria during pregnancy with sulphadoxine-pyrimethamine (IPTp-SP) policy in 2013. This study aimed to estimate the proportion of and identify factors associated with the uptake of at least three doses of IPTp with SP among pregnant women in Malawi after the adoption and operationalisation of updated WHO IPTp-SP policy. Methods: The 2015-16 Malawi Demographic and Health Survey dataset was analysed. Of 1,219 women aged 15-49 years who had live births and the children were born after the date of July 2015, 1,069 women were included in the analysis. Bivariate and multiple logistic regression were used in data analysis. The statistical analysis took into account a complex survey sample design. Results: Of the 1,069 women, 447 (42%, 95% CI: 38.1-45.6) received three (optimal) or more doses of IPTp-SP. Less than half (47%) managed to attend at least four antenatal care (ANC) clinics. Only 52% received optimal SP doses among those who made at least four ANC visits. Only the number of ANC visits was associated with the optimal uptake of SP. Women who attended ANC three times only and those who visited ANC once or twice only were less likely to receive at least three doses of SP than those who managed to attend ANC at least four times during pregnancy (AOR=0.71, 95% CI 0.49-1.02) and (AOR=0.12, 95% CI 0.06-0.21) respectively. Conclusions: To achieve effective malaria prevention in pregnancy, IPTP-SP is used alongside other interventions. However, there is low uptake of optimal SP doses in Malawi, and this seems to be associated with the number of ANC visits. Moreover, there is limited effectiveness of an increased number of ANC visits on the uptake of optimal SP doses. Further research should be done to explore health systems factors affecting uptake of optimal IPTp with SP doses during pregnancy.

scholarly journals Insecticides Susceptibility Status of Malaria Vectors in a High Malaria Endemic Tribal District Gadchiroli (Maharashtra) of India

2021 ◽  
Vol 53 (03) ◽  
pp. 33-50
Author(s):  
RK Singh ◽  
Keyword(s):  
World Health ◽  
Malaria Vectors ◽  
Synthetic Pyrethroids ◽  
Lambda Cyhalothrin ◽  
Deltamethrin Resistance ◽  
Cone Bioassay ◽  
Susceptibility Tests ◽  
Health Organization ◽  
Susceptibility Status ◽  
Major Malaria Vector

Background and Objective: The current study was undertaken to determine insecticide susceptibility of malaria vectors in various villages of high malaria endemic PHCs of Gadchiroli district of Maharashtra. Methods: Adult malaria vectors were collected from the human dwellings/ cattle sheds of 156 villages of 18 malaria endemic PHCs. Susceptibility tests were carried out for different insecticides against An. culicifacies and An. fluviatilis mosquitoes as per the World Health Organization (WHO) procedure. Cone bioassays were also done to assess the quality and efficacy of indoor residual spray. Results:An. fluviatilis could be collected from 23 villages only and all the populations were fully susceptible to synthetic pyrethroid (deltamethrin) while being tolerant to organophosphorous (malathion). Susceptibility of An. culicifacies from 156 villages indicated that only 3 populations of An. culicifacies were resistant to deltamethrin while 57 populations were fully susceptible and other 96 populations were tolerant to deltamethrin. Resistance was recorded in 25 populations of An. culicifacies against malathion and 30 populations were tolerant to malathion insecticide. Remaining populations of An. fluviatilis and An. culicifacies were highly resistant to organochlorine. Results of cone bioassay revealed the mortality ranged from 32.5-51.1% on cemented and 27.5-43.3% on the mud wall sprayed with lambda cyhalothrin. Conclusion: The current study indicates that resistance has developed to synthetic pyrethroids in the major malaria vector An. culicifacies. Therefore, there is an urgent need for the evaluation of new insecticide molecules for better control of malaria vectors.

scholarly journals The promise, problems and pitfalls of mass drug administration for malaria elimination: a qualitative study with scientists and policymakers

2018 ◽  
Vol 11 (3) ◽  
pp. 166-176 ◽  
Author(s):  
Nils Kaehler ◽  
Bipin Adhikari ◽  
Phaik Yeong Cheah ◽  
Nicholas P J Day ◽  
Daniel H Paris ◽  
...  
Keyword(s):  
Drug Administration ◽  
Mass Drug Administration ◽  
Malaria Elimination ◽  
Artemisinin Resistance ◽  
Malaria Prevention ◽  
Evidence Base ◽  
World Health ◽  
Pilot Studies ◽  
Target Populations ◽  
Health Organization

Abstract Background The emergence of artemisinin resistance in the Greater Mekong Subregion (GMS) has prompted urgent containment measures. One possible approach is mass drug administration (MDA). This article explores attitudes towards and perceptions of MDA for malaria elimination among policymakers and leading malariologists. Methods Thirty-two semistructured interviews (SSI) were conducted with policymakers (n=17) and principal investigators (n=15) selected based on their involvement in malaria prevention, control and elimination in the GMS. Interviews were audio recorded and transcribed for qualitative content (thematic) analysis using NVivo (QSR International, Doncaster, Victoria, Australia). Results Researchers and policymakers described reluctance and consequently delays to pilot MDA for malaria elimination. Most policymakers and some researchers reported concerns around the evidence base, citing a lack of data on its effectiveness and appropriate target populations. There were also worries about promoting resistance. Other issues included a previous lack of support from the World Health Organization, past MDAs, the remoteness of target populations and challenges explaining the rationale for MDA. Conclusions The complex rationale for MDA for malaria elimination, mistaking pilot studies for implementation, past experiences with MDA, difficulties in selecting appropriate sites and the WHO’s lack of clear backing undermined the support for MDA for malaria elimination.

Sign in / Sign up

Export Citation Format

Share Document