scholarly journals Defining the larval habitat: abiotic and biotic parameters associated with Anopheles farauti productivity

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Kimberley McLaughlin ◽  
Thomas R. Burkot ◽  
Jance Oscar ◽  
Nigel W. Beebe ◽  
Tanya L. Russell
Keyword(s):  
Vector Control ◽  
Control Strategy ◽  
World Health ◽  
Effective Control ◽  
Biological Parameters ◽  
Insecticide Treated Nets ◽  
Larval Habitats ◽  
Anopheles Farauti ◽  
Larval Source Management ◽  
Source Management

Abstract Background In the Solomon Island, the dominant malaria vector, Anopheles farauti, is highly anthropophagic and increasingly exophilic and early biting. While long-lasting insecticide-treated nets remain effective against An. farauti, supplemental vector control strategies will be needed to achieve malaria elimination. Presently, the only World Health Organization recommended supplemental vector control strategy is larval source management (LSM). Effective targeted larval source management requires understanding the associations between abiotic, chemical and biological parameters of larval habitats with the presence or density of vector larvae. Methods Potential and actual An. farauti larval habitats were characterized for presence and density of larvae and associated abiotic, chemical and biological parameters. Results A third of all sampled potential habitats harboured An. farauti larvae with 80% of An. farauti positive habitats being in three habitat classifications (swamps/lagoons, transient pools and man-made holes). Large swamps were the most abundant positive habitats surveyed (43% of all An. farauti positive habitats). Habitats with An. farauti larvae were significantly associated with abiotic (pH, nitrate, ammonia and phosphate concentrations and elevated temperature) and biotic (predators) parameters. Conclusion Large swamps and lagoons are the largest and most abundant An. farauti habitats in the Solomon Islands. Positive habitats were more frequently associated with the presence of predators (vertebrates and invertebrates) and higher water temperatures. Cohabitation with predators is indicative of a complex habitat ecosystem and raises questions about the potential of biological control as an effective control strategy. Increased presence of An. farauti with higher water temperature suggests a potential explanation for the coastal distribution of this species which is not found inland at elevated altitudes where temperatures would be cooler.

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 Estimating the Optimal Control of Zoonotic Visceral Leishmaniasis by the Use of a Mathematical Model

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Laila Massad Ribas ◽  
Vera Lucia Zaher ◽  
Helio Junji Shimozako ◽  
Eduardo Massad
Keyword(s):  
Mathematical Model ◽  
Optimal Control ◽  
Visceral Leishmaniasis ◽  
Vector Control ◽  
Control Strategy ◽  
Control Strategies ◽  
Effective Control ◽  
Alternative Control ◽  
Alternative Strategies ◽  
Zoonotic Visceral Leishmaniasis

We argue that the strategy of culling infected dogs is not the most efficient way to control zoonotic visceral leishmaniasis (ZVL) and that, in the presence of alternative control strategies with better potential results, official programs of compulsory culling adopted by some countries are inefficient and unethical. We base our arguments on a mathematical model for the study of control strategies against ZVL, which allows the comparison of the efficacies of 5, alternative strategies. We demonstrate that the culling program, previously questioned on both theoretical and practical grounds is the less effective control strategy. In addition, we show that vector control and the use of insecticide-impregnated dog collars are, by far, more efficient at reducing the prevalence of ZVL in humans.

scholarly journals Effectiveness of vector control methods for the control of cutaneous and visceral leishmaniasis: A meta-review

2021 ◽  
Vol 15 (5) ◽  
pp. e0009309
Author(s):  
Carlos Alberto Montenegro Quiñonez ◽  
Silvia Runge-Ranzinger ◽  
Kazi Mizanur Rahman ◽  
Olaf Horstick
Keyword(s):  
Visceral Leishmaniasis ◽  
Vector Control ◽  
Systematic Reviews ◽  
Indoor Residual Spraying ◽  
World Health ◽  
Control Methods ◽  
Insecticide Treated Nets ◽  
Meta Review ◽  
Environmental Measures ◽  
Meta Analyses

Elimination of visceral leishmaniasis (VL) in Southeast Asia and global control of cutaneous leishmaniasis (CL) and VL are priorities of the World Health Organization (WHO). But is the existing evidence good enough for public health recommendations? This meta-review summarises the available and new evidence for vector control with the aims of establishing what is known about the value of vector control for the control of CL and VL, establishing gaps in knowledge, and particularly focusing on key recommendations for further scientific work. This meta-review follows the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) criteria, including (1) systematic reviews and meta-analyses (SRs/MAs) for (2) vector control methods and strategies and (3) for the control of CL and/or VL. Nine SRs/MAs were included, with different research questions and inclusion/exclusion criteria. The methods analysed for vector control can be broadly classified into (1) indoor residual spraying (IRS); (2) insecticide-treated nets (ITNs; including insecticide-impregnated bednets); (3) insecticide-treated curtains (ITCs; including insecticide-treated house screening); (4) insecticide-treated bedsheets (ITSs) and insecticide-treated fabrics (ITFs; including insecticide-treated clothing) and (5) durable wall lining (treated with insecticides) and other environmental measures to protect the house; (6) control of the reservoir host; and (7) strengthening vector control operations through health education. The existing SRs/MAs include a large variation of different primary studies, even for the same specific research sub-question. Also, the SRs/MAs are outdated, using available information until earlier than 2018 only. Assessing the quality of the SRs/MAs, there is a considerable degree of variation. It is therefore very difficult to summarise the results of the available SRs/MAs, with contradictory results for both vector indices and—if available—human transmission data. Conclusions of this meta-review are that (1) existing SRs/MAs and their results make policy recommendations for evidence-based vector control difficult; (2) further work is needed to establish efficacy and community effectiveness of key vector control methods with specific SRs and MAs (3) including vector and human transmission parameters; and (4) attempting to conclude with recommendations in different transmission scenarios.

scholarly journals Designing effective control of dengue with combined interventions

2020 ◽  
Vol 117 (6) ◽  
pp. 3319-3325 ◽  
Author(s):  
Thomas J. Hladish ◽  
Carl A. B. Pearson ◽  
Kok Ben Toh ◽  
Diana Patricia Rojas ◽  
Pablo Manrique-Saide ◽  
...  
Keyword(s):  
Vector Control ◽  
Large Scale ◽  
Vaccination Campaign ◽  
Indoor Residual Spraying ◽  
World Health ◽  
Effective Control ◽  
Management Options ◽  
Control Programs ◽  
Resource Limitations ◽  
Health Organization

Viruses transmitted by Aedes mosquitoes, such as dengue, Zika, and chikungunya, have expanding ranges and seem unabated by current vector control programs. Effective control of these pathogens likely requires integrated approaches. We evaluated dengue management options in an endemic setting that combine novel vector control and vaccination using an agent-based model for Yucatán, Mexico, fit to 37 y of data. Our intervention models are informed by targeted indoor residual spraying (TIRS) experiments; trial outcomes and World Health Organization (WHO) testing guidance for the only licensed dengue vaccine, CYD-TDV; and preliminary results for in-development vaccines. We evaluated several implementation options, including varying coverage levels; staggered introductions; and a one-time, large-scale vaccination campaign. We found that CYD-TDV and TIRS interfere: while the combination outperforms either alone, performance is lower than estimated from their separate benefits. The conventional model hypothesized for in-development vaccines, however, performs synergistically with TIRS, amplifying effectiveness well beyond their independent impacts. If the preliminary performance by either of the in-development vaccines is upheld, a one-time, large-scale campaign followed by routine vaccination alongside aggressive new vector control could enable short-term elimination, with nearly all cases avoided for a decade despite continuous dengue reintroductions. If elimination is impracticable due to resource limitations, less ambitious implementations of this combination still produce amplified, longer-lasting effectiveness over single-approach interventions.

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 Are Dawn Collections of Anopheles stephensi a Better Method To Estimate the Resting Vector Density? A Study from Chennai, India

2021 ◽  
Author(s):  
Sangamithra Ravishankaran ◽  
Aswin Asokan ◽  
N. Johnson Amala Justin ◽  
Shalu Thomas ◽  
Manu Thomas Mathai ◽  
...  
Keyword(s):  
Longitudinal Study ◽  
Vector Control ◽  
Malaria Transmission ◽  
Anopheles Stephensi ◽  
Urban Setting ◽  
Larval Source Management ◽  
Vector Density ◽  
Management Measures ◽  
Close Proximity ◽  
Source Management

The study was an attempt to capture Anopheles stephensi from cattle sheds during dawn to understand the realistic density of the resting mosquitoes. A 2-year longitudinal study was carried out in cattle sheds in close proximity to the human dwellings to collect the resting vector mosquitoes. The man-hour density of A. stephensi ranged from 24.7 to 206.5. The vector incrimination results indicated 0.15% of A. stephensi infected with Pv210 in 2015 and 0.09% in 2016. The current study has revealed that cattle sheds are the preferred resting place of A. stephensi and that dawn is the perfect time to collect and estimate its densities. Hence, adult vector control may also be given due importance in addition to the routine larval source management measures to curb malaria transmission in an urban setting.

scholarly journals The Prevalence of Congenital Malaria

2019 ◽  
Vol 8 (1) ◽  
pp. 22-29
Author(s):  
Etefia Uwem Etefia
Keyword(s):  
Pregnant Women ◽  
Cost Effective ◽  
World Health ◽  
Effective Control ◽  
Insecticide Treated Nets ◽  
The World ◽  
Health Organization ◽  
The Tropics ◽  
Congenital Malaria ◽  
Effective Case

This study was aimed at highlighting on the prevalence of malaria among pregnant women in Nigeria within the last ten years. The prevalence of congenital malaria in Nigeria varies and it affects every geopolitical zone in Nigeria. This is because Nigeria like other countries in the tropics and subtropics has factors which favour the survival of mosquito. Although the World Health Organization (WHO) recommends the use of insecticide treated nets and effective case management of uncomplicated malaria as a feasible and cost-effective control strategy, Nigeria remains one of the worst affected countries in the world with malaria among pregnant women and neonates. This paper recommends more programs to the menace of this infection among pregnant women and neonates in Nigeria.

scholarly journals Cost of Community-Led Larval Source Management and House Improvement for Malaria Control: A Cost Analysis Within A Cluster-Randomised Trial in A Rural District in Malawi

2020 ◽  
Author(s):  
Mphatso Dennis Phiri ◽  
Robert Sean McCann ◽  
Alinune Nathanael Kabaghe ◽  
Henk van den Berg ◽  
Tumaini Malenga ◽  
...  
Keyword(s):  
Cost Analysis ◽  
Vector Control ◽  
Malaria Control ◽  
Randomised Trial ◽  
Wire Mesh ◽  
Sensitivity Analyses ◽  
Larval Source Management ◽  
House Improvement ◽  
Implementation Costs ◽  
Source Management

Abstract Background: House improvement (HI) to prevent mosquito house entry, and larval source management (LSM) targeting aquatic mosquito stages to prevent development into adult forms, are promising complementary interventions to current malaria vector control strategies. Lack of evidence on costs and cost-effectiveness of community-led implementation of HI and LSM has hindered wide scale adoption. This study presents an incremental cost analysis of community-led implementation of HI and LSM, in a factorial design trial, in addition to standard national malaria control interventions in Chikwawa district, southern Malawi.Methods: In the trial, LSM comprised draining, filling, and Bacillus thuringiensis israelensis larvicide application, while HI involved closing of eaves and gaps on walls, and screening windows and ventilation spaces with wire mesh. Communities implemented all interventions. Costs were estimated retrospectively using the ‘ingredients approach’, combining both ‘bottom-up’ and ‘top-down approaches’, from the societal perspective. To estimate the cost of independently implementing each intervention arm, resources shared between trial arms (e.g. overheads) were allocated to each consuming arm using proxies developed based on share of resource input quantities consumed. Incremental implementation costs (in 2017 US$) are presented for HI only, LSM only and HI+LSM arms. In sensitivity analyses, the effect of varying costs of important inputs on estimated costs was explored. Results: The total economic program costs of community-led HI and LSM implementation was $626,152. Economic implementation costs of HI, LSM and HI+LSM were estimated as $27.04, $25.06 and $33.44, per person per year, respectively. Staff, transport and labour costs, but not larvicide or screening material, were the major cost drivers across all interventions. Estimated costs were sensitive to changes in staff costs and population covered. Conclusions: In the context of the trial, the economic costs of community-led HI and LSM implementation were high compared to conventional vector control interventions. Several factors, including the year-round implementation of LSM and low human population density could explain the high costs. The factorial trial design necessitated use of proxies to allocate costs shared between trial arms, which may limit generalisability of estimated costs where different designs are used. Nevertheless, costs may inform planners of future similar intervention packages. Trial registration: Not applicable. The original trial was registered with The Pan African Clinical Trials Registry on 3 March 2016, trial number PACTR201604001501493.

scholarly journals Towards a Sustainable Vector-Control Strategy in the Post Kala-Azar Elimination Era

2021 ◽  
Vol 11 ◽  
Author(s):  
Rajesh Garlapati ◽  
Eva Iniguez ◽  
Tiago D. Serafim ◽  
Prabhas K. Mishra ◽  
Basab Rooj ◽  
...  
Keyword(s):  
Vector Control ◽  
Control Strategy ◽  
Indoor Residual Spraying ◽  
Public Health Problem ◽  
Control Measures ◽  
World Health ◽  
Sand Fly ◽  
Current Vector ◽  
Kala Azar ◽  
Vector Control Strategy

Visceral leishmaniasis (VL) is a potentially deadly parasitic disease. In the Indian sub-continent, VL is caused by Leishmania donovani and transmitted via the bite of an infected Phlebotomus argentipes female sand fly, the only competent vector species in the region. The highest disease burden is in the northern part of the Indian sub-continent, especially in the state of Bihar. India, Bangladesh, and Nepal embarked on an initiative, coordinated by World Health Organization, to eliminate VL as a public health problem by the year 2020. The main goal is to reduce VL incidence below one case per 10,000 people through early case-detection, prompt diagnosis and treatment, and reduction of transmission using vector control measures. Indoor residual spraying, a major pillar of the elimination program, is the only vector control strategy used by the government of India. Though India is close to its VL elimination target, important aspects of vector bionomics and sand fly transmission dynamics are yet to be determined. To achieve sustained elimination and to prevent a resurgence of VL, knowledge gaps in vector biology and behavior, and the constraints they may pose to current vector control methods, need to be addressed. Herein, we discuss the successes and failures of previous and current vector-control strategies implemented to combat kala-azar in Bihar, India, and identify gaps in our understanding of vector transmission towards development of innovative tools to ensure sustained vector control in the post-elimination period.

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