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Luker HA. A critical review of current laboratory methods used to evaluate mosquito repellents. FRONTIERS IN INSECT SCIENCE 2024; 4:1320138. [PMID: 38469342 PMCID: PMC10926509 DOI: 10.3389/finsc.2024.1320138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 01/02/2024] [Indexed: 03/13/2024]
Abstract
Pathogens transmitted by mosquitoes threaten human health around the globe. The use of effective mosquito repellents can protect individuals from contracting mosquito-borne diseases. Collecting evidence to confirm and quantify the effectiveness of a mosquito repellent is crucial and requires thorough standardized testing. There are multitudes of methods to test repellents that each have their own strengths and weaknesses. Determining which type of test to conduct can be challenging and the collection of currently used and standardized methods has changed over time. Some of these methods can be powerful to rapidly screen numerous putative repellent treatments. Other methods can test mosquito responses to specific treatments and measure either spatial or contact repellency. A subset of these methods uses live animals or human volunteers to test the repellency of treatments. Assays can greatly vary in their affordability and accessibility for researchers and/or may require additional methods to confirm results. Here I present a critical review that covers some of the most frequently used laboratory assays from the last two decades. I discuss the experimental designs and highlight some of the strengths and weaknesses of each type of method covered.
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Affiliation(s)
- Hailey A. Luker
- Molecular Vector Physiology Laboratory, Department of Biology, New Mexico State University, Las Cruces, NM, United States
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2
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Bauer IL. The oral repellent - science fiction or common sense? Insects, vector-borne diseases, failing strategies, and a bold proposition. Trop Dis Travel Med Vaccines 2023; 9:7. [PMID: 37381000 DOI: 10.1186/s40794-023-00195-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 06/09/2023] [Indexed: 06/30/2023] Open
Abstract
Over the last decades, unimaginable amounts of money have gone into research and development of vector control measures, repellents, treatment, and vaccines for vector borne diseases. Technological progress and scientific breakthroughs allowed for ever more sophisticated and futuristic strategies. Yet, each year, millions of people still die or suffer from potentially serious consequences of malaria or dengue to more recent infections, such as zika or chikungunya, or of debilitating consequences of neglected tropical diseases. This does not seem value for money. In addition, all current vector control strategies and personal protection methods have shortcomings, some serious, that are either destructive to non-target species or unsatisfactory in their effectiveness. On the other hand, the rapid decline in insect populations and their predators reflects decades-long aggressive and indiscriminate vector control. This major disruption of biodiversity has an impact on human life not anticipated by the well-meaning killing of invertebrates. The objective of this paper is to re-examine current control methods, their effectiveness, their impact on biodiversity, human and animal health, and to call for scientific courage in the pursuit of fresh ideas. This paper brings together topics that are usually presented in isolation, thereby missing important links that offer potential solutions to long-standing problems in global health. First, it serves as a reminder of the importance of insects to human life and discusses the few that play a role in transmitting disease. Next, it examines critically the many currently employed vector control strategies and personal protection methods. Finally, based on new insights into insect chemo-sensation and attractants, this perspective makes a case for revisiting a previously abandoned idea, the oral repellent, and its use via currently successful methods of mass-application. The call is out for focused research to provide a powerful tool for public health, tropical medicine, and travel medicine.
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Affiliation(s)
- Irmgard L Bauer
- College of Healthcare Sciences, Academy - Tropical Health and Medicine, James Cook University, Townsville, QLD, 4811, Australia.
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3
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Du F, Rupp H, Jariyavidyanont K, Janke A, Petzold A, Binder W, Androsch R. 3D-printing of the polymer/insect-repellent system poly(l-lactic acid)/ethyl butylacetylaminopropionate (PLLA/IR3535). Int J Pharm 2022; 624:122023. [PMID: 35843363 DOI: 10.1016/j.ijpharm.2022.122023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 07/11/2022] [Accepted: 07/12/2022] [Indexed: 11/24/2022]
Abstract
The polymer/solvent system poly(l-lactic acid)/ethyl butylacetylaminopropionate (PLLA/IR3535) is regarded as an insect-repellent-delivery system, serving, e.g., for fighting mosquito-borne tropical diseases. In such systems the solid polymer hosts the liquid repellent, with the latter slowly released to the environment, expelling mosquitoes. As a new approach, exceeding prior work about application of different technologies to obtain such devices, in this work, samples of the polymer/repellent system PLLA/IR3535 were prepared by 3D-printing. The experiments showed that it is possible to print 3D-parts containing up to 25 m% repellent, with an only minor loss of repellent during the printing process. For samples containing low amount of repellent, crystallization of PLLA was suppressed due to the rather fast cooling step and the low bed temperature of around 25 °C, being lower than the glass transition temperature of the homogeneous polymer/repellent strands. At higher repellent concentration, due to the lowering of the glass transition temperature to near or even below ambient temperature, the crystallinity slowly increased during storage after printing. For all samples, regardless of the initial repellent concentration, the repellent-release rate increases with temperature, and at ambient temperature the release-time constant is in the order of 10 days. The study successfully proved the applicability of the technology of extrusion-based 3D-printing for the preparation of polymer parts with a specific shape/design containing mosquito-repellent at a concentration which raises the expectation to be used as a repellent delivery-device.
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Affiliation(s)
- Fanfan Du
- Interdisciplinary Center for Transfer-oriented Research in Natural Sciences, Martin Luther University Halle-Wittenberg, 06099 Halle/Saale, Germany
| | - Harald Rupp
- Institute of Chemistry, Martin Luther University Halle-Wittenberg, 06099 Halle/Saale, Germany
| | - Katalee Jariyavidyanont
- Interdisciplinary Center for Transfer-oriented Research in Natural Sciences, Martin Luther University Halle-Wittenberg, 06099 Halle/Saale, Germany
| | - Andreas Janke
- Leibniz-Institut für Polymerforschung Dresden e. V., Hohe Str. 6, 01069 Dresden, Germany
| | - Albrecht Petzold
- Institute of Physics, Martin Luther University Halle-Wittenberg, 06099 Halle/Saale, Germany
| | - Wolfgang Binder
- Institute of Chemistry, Martin Luther University Halle-Wittenberg, 06099 Halle/Saale, Germany.
| | - René Androsch
- Interdisciplinary Center for Transfer-oriented Research in Natural Sciences, Martin Luther University Halle-Wittenberg, 06099 Halle/Saale, Germany.
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Ferreira HRP, Cabral RLB, Queiroga TBD, Guedes PMM, Lourenço de Assis AB, de Moura Barbosa T, do Nascimento JHO, Gama RA. The repellency effect of icaridin nanostructural solution applied on cotton knitting fabric against Lutzomyia longipalpis. Parasitol Res 2022; 121:2673-2681. [PMID: 35821144 DOI: 10.1007/s00436-022-07595-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 07/04/2022] [Indexed: 11/30/2022]
Abstract
The use of repellents is considered an alternative against biting insects, including Lutzomyia longipalpis (Diptera: Psychodidae), the main vector of the protozoan Leishmania infantum, visceral leishmaniasis's (VL) etiologic agent in the Americas. This study aimed to evaluate the repellent efficacy of icaridin nanostructured solution applied on cotton knitting fabric against L. longipalpis. Arm-in-cage tests were performed in eight volunteers at different concentrations (5%, 10%, 25%, and 50%), using L. longipalpis (n = 30). The bioassay was performed in 1, 24, 48, 72, 96, 120, and 144 h after impregnation and one test after washing the fabrics with icaridin. The total repellency rate (%R) > 95% was used as a reference to define a minimum effective concentration (MEC). The results revealed that the insects' landing mean decreased significantly in different icaridin concentrations, compared with the control tests (p < 0.05) and the 25% and 50% concentrations compared to lower concentration (5%) (p < 0.05). The higher concentrations (25% and 50%) provided longer complete protection times (CPTs) with 120 and 144 h of protection, respectively and the %R of 100% for 72 and 96 h after impregnation, respectively. The 25% was the MEC (%R Total = 98.18%). Our results indicate, for the first time, that icaridin nanostructured solution applied on cotton knitting fabric proved to be an efficient repellent against L. longipalpis with the presence of repellent action even after washing. The concentration of 25% showed better efficiency and may become an efficient method for L. longipalpis biting control.
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Affiliation(s)
- Henrique Rafael Pontes Ferreira
- Parasitary Biology Post-Graduate Program, Biosciences Center, Federal University of Rio Grande Do Norte, Av. Senador Salgado Filho, 3000, Natal, Candelária, RN 59.072-970, Brazil.
| | - Rivaldo Leonn Bezerra Cabral
- IMNG - Innovation in Micro and Nanotechnologies Group, Center of Technology, Federal University of Rio Grande Do Norte - UFRN, Natal, Rio Grande do Norte, Brazil
| | - Tamyres Bernadete Dantas Queiroga
- Pharmaceutical Sciences Post-Graduate Program, Federal University of Rio Grande Do Norte, Av. Sen. Salgado Filho, 3000, Natal, Candelária, RN 59.072-970, Brazil
| | - Paulo Marcos Matta Guedes
- Parasitary Biology Post-Graduate Program, Biosciences Center, Federal University of Rio Grande Do Norte, Av. Senador Salgado Filho, 3000, Natal, Candelária, RN 59.072-970, Brazil
| | - Ana Beatriz Lourenço de Assis
- Parasitary Biology Post-Graduate Program, Biosciences Center, Federal University of Rio Grande Do Norte, Av. Senador Salgado Filho, 3000, Natal, Candelária, RN 59.072-970, Brazil
| | - Taciano de Moura Barbosa
- Parasitary Biology Post-Graduate Program, Biosciences Center, Federal University of Rio Grande Do Norte, Av. Senador Salgado Filho, 3000, Natal, Candelária, RN 59.072-970, Brazil
| | - José Heriberto Oliveira do Nascimento
- IMNG - Innovation in Micro and Nanotechnologies Group, Center of Technology, Federal University of Rio Grande Do Norte - UFRN, Natal, Rio Grande do Norte, Brazil
| | - Renata Antonaci Gama
- Parasitary Biology Post-Graduate Program, Biosciences Center, Federal University of Rio Grande Do Norte, Av. Senador Salgado Filho, 3000, Natal, Candelária, RN 59.072-970, Brazil
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Yener H, Erdmann R, Jariyavidyanont K, Mapossa A, Focke WW, Hillrichs G, Androsch R. Slow-DEET-Release Mosquito-Repellent System Based on Poly(butylene succinate). ACS OMEGA 2022; 7:8377-8384. [PMID: 35309496 PMCID: PMC8928517 DOI: 10.1021/acsomega.1c05897] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 12/22/2021] [Indexed: 06/14/2023]
Abstract
Bio-sourced and biodegradable poly(butylene succinate) (PBS) strands containing up to 40 m% mosquito-repellent N,N-diethyl-3-methylbenzamide (DEET) were obtained by extrusion, for an initial evaluation of the DEET evaporation characteristics and the possible application of such strands as biodegradable slow-release repellent-delivery devices. For DEET concentrations up to 20 m%, DEET is entrapped in the semicrystalline spherulitic superstructure of PBS. In contrast, at higher DEET concentrations, the liquid repellent, at least partially, is not fully incorporated in the PBS spherulites rather than segregates to form an own macrophase. Quantification of the release of DEET to the environment by thermogravimetric analysis at different temperatures between 60 and 100 °C allowed estimation of the evaporation rate at lower service temperatures, suggesting an extremely low release rate with a time constant of the order of magnitude of 1-2 years at 25 °C, independent of the initial concentration.
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Affiliation(s)
- Hande
Ece Yener
- Interdisciplinary
Center for Transfer-oriented Research in Natural Sciences (IWE TFN), Martin Luther University Halle-Wittenberg, 06099 Halle/Saale, Germany
| | - Rafael Erdmann
- Institute
for Biopolymers and Sustainability (ibp), University of Applied Sciences Hof, Alfons-Goppel-Platz 1, 95028 Hof/Saale, Germany
| | - Katalee Jariyavidyanont
- Interdisciplinary
Center for Transfer-oriented Research in Natural Sciences (IWE TFN), Martin Luther University Halle-Wittenberg, 06099 Halle/Saale, Germany
| | - António
B. Mapossa
- Institute
of Applied Materials, Department of Chemical Engineering, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
- Institute
for Sustainable Malaria Control & MRC Collaborating Centre for
Malaria Research, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Walter W. Focke
- Institute
of Applied Materials, Department of Chemical Engineering, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
- Institute
for Sustainable Malaria Control & MRC Collaborating Centre for
Malaria Research, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Georg Hillrichs
- Department
of Engineering and Natural Sciences, University
of Applied Sciences Merseburg, Eberhard-Leibnitz-Straße 2, 06217 Merseburg, Germany
| | - René Androsch
- Interdisciplinary
Center for Transfer-oriented Research in Natural Sciences (IWE TFN), Martin Luther University Halle-Wittenberg, 06099 Halle/Saale, Germany
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Rashkov P. Modeling repellent-based interventions for control of vector-borne diseases with constraints on extent and duration. MATHEMATICAL BIOSCIENCES AND ENGINEERING : MBE 2022; 19:4038-4061. [PMID: 35341285 DOI: 10.3934/mbe.2022185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
We study a simple model for a vector-borne disease with control intervention based on clothes and household items treated with mosquito repellents, which has constraints on the extent (population coverage) and on the time duration reflecting technological and physical properties. We compute first, the viability kernel of initial data of the model for which exists an optimal control that maintains the infected host population below a given cap for all future times. Second, we use the viability kernel to compute the set of initial data of the model for which exists an optimal control that brings this population below the cap in a time period not exceeding the intervention's duration. We discuss applications of this framework in predicting and evaluating the performance of control interventions under the given type of constraints.
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Affiliation(s)
- Peter Rashkov
- Institute of Mathematics and Informatics, Bulgarian Academy of Sciences, Akademik Georgi Bonchev, blok 8, 1113 Sofia, Bulgaria
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Jung H, An H, Lee M, Lee J, Tak JH. Comparative Efficacy of Commercial Liquid and Mat-Type Electric Vaporizer Insecticides Against Asian Tiger Mosquito (Diptera: Culicidae). JOURNAL OF MEDICAL ENTOMOLOGY 2021; 58:2274-2283. [PMID: 34021566 DOI: 10.1093/jme/tjab087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Indexed: 06/12/2023]
Abstract
Mat and liquid-type electric insecticide vaporizers continuously emit insecticides into the surrounding air. Because both the target insects, mostly mosquitoes, and humans are exposed to those insecticides, it is crucial to understand and monitor their deposition and spatial distribution in treated areas. In the current study, we examined the evaporation of insecticides from seven commercial liquid and mat vaporizers and measured their knock-down and insecticidal activity against the adult females of the Asian tiger mosquito, Aedes albopictus (Skuse). Electric vaporizers from three manufactures had differences in their heaters and active ingredients. Most had continued evaporation during hourly and daily monitoring; however, some liquid vaporizers failed to continue emission to their designated end periods. Overall, mosquitoes located at the upper position in a Peet-Grady chamber and in a field-simulation room exhibited faster knock-down activity than did mosquitoes in other areas, indicating that the insecticides accumulated on the ceiling area. Although most of mat and liquid vaporizers had <60 min of average KT90 values when tested in the Peet-Grady chamber (1.8 × 1.8 × 1.8 m), they failed to have any knock-down in 2 h of observation in the field-simulation room (6.8 × 3.4 × 2.7 m) but showed 72. 8 ± 11.7% and 56. 7 ± 7.3% knock-down in the mat and liquid vaporizers, respectively, in 3 h of operation. Further study will be required to examine whether this relatively limited efficacy can be compensated by other physiological and behavioral effects, including disruption in host-seeking or blood-sucking activities.
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Affiliation(s)
- Hun Jung
- Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, South Korea
| | - Huijun An
- Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, South Korea
| | - Minjin Lee
- Consumer Product & Environment Business Division, KOTITI Testing & Research Institute, Seongnam, Gyeonggi 13202, South Korea
| | - Jieun Lee
- Consumer Product & Environment Business Division, KOTITI Testing & Research Institute, Seongnam, Gyeonggi 13202, South Korea
| | - Jun-Hyung Tak
- Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, South Korea
- Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826, South Korea
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Luker HA, Rodriguez S, Kandel Y, Vulcan J, Hansen IA. A novel Tick Carousel Assay for testing efficacy of repellents on Amblyomma americanum L.. PeerJ 2021; 9:e11138. [PMID: 33976963 PMCID: PMC8067905 DOI: 10.7717/peerj.11138] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 03/01/2021] [Indexed: 11/23/2022] Open
Abstract
Ticks are important vectors of human and veterinary diseases. A primary way ticks gain access to human hosts is by engaging to clothing. Repellents or acaricides sprayed onto fabric are used to deter ticks’ access to human hosts. However, there are a limited amount of standardized laboratory assays that can determine the potency and efficacy of repellents. We present a novel fabric-engagement assay referred to as the ‘Tick Carousel Assay’. This assay utilizes fabric brushing past ticks located on an artificial grass patch and measures tick engagements to fabric over time. After screening a variety of tick species, we used the lone star tick (Amblyomma americanum) to test the efficacy of four commonly used active ingredients in repellents: DEET, Picaridin, IR3535, and Oil of Lemon Eucalyptus. Repellency was tested immediately, after three hours, and six hours post application to fabric. Our data show that each repellent we tested significantly reduced the number of tick engagements to fabric for at least 6 hours. We did not find significant differences in repellent efficacy between the four active ingredients tested directly and three hours after application. After six hours, Oil of Lemon Eucalyptus repelled ticks more than the other active ingredients. We show that our Tick Carousel Assay provides an affordable, repeatable, and standardized way to compare and test repellent efficacy on treated fabrics. Our results confirm that commonly used repellents applied to fabric are an effective way to reduce tick engagement.
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Affiliation(s)
- Hailey A Luker
- Department of Biology, New Mexico State University, Las Cruces, NM, United States of America
| | - Stacy Rodriguez
- Department of Biology, New Mexico State University, Las Cruces, NM, United States of America
| | - Yashoda Kandel
- Department of Biology, New Mexico State University, Las Cruces, NM, United States of America
| | - Julia Vulcan
- Department of Biology, New Mexico State University, Las Cruces, NM, United States of America
| | - Immo A Hansen
- Department of Biology, New Mexico State University, Las Cruces, NM, United States of America
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Mapossa AB, Focke WW, Tewo RK, Androsch R, Kruger T. Mosquito-repellent controlled-release formulations for fighting infectious diseases. Malar J 2021; 20:165. [PMID: 33761967 PMCID: PMC7988998 DOI: 10.1186/s12936-021-03681-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Accepted: 03/03/2021] [Indexed: 12/18/2022] Open
Abstract
Malaria is a principal cause of illness and death in countries where the disease is endemic. Personal protection against mosquitoes using repellents could be a useful method that can reduce and/or prevent transmission of mosquito-borne diseases. The available repellent products, such as creams, roll-ons, and sprays for personal protection against mosquitoes, lack adequate long-term efficacy. In most cases, they need to be re-applied or replaced frequently. The encapsulation and release of the repellents from several matrices has risen as an alternative process for the development of invention of repellent based systems. The present work reviews various studies about the development and use of repellent controlled-release formulations such as polymer microcapsules, polymer microporous formulations, polymer micelles, nanoemulsions, solid-lipid nanoparticles, liposomes and cyclodextrins as new tools for mosquito-borne malaria control in the outdoor environment. Furthermore, investigation on the mathematical modelling used for the release rate of repellents is discussed in depth by exploring the Higuchi, Korsmeyer-Peppas, Weibull models, as well as the recently developed Mapossa model. Therefore, the studies searched suggest that the final repellents based-product should not only be effective against mosquito vectors of malaria parasites, but also reduce the biting frequency of other mosquitoes transmitting diseases, such as dengue fever, chikungunya, yellow fever and Zika virus. In this way, they will contribute to the improvement in overall public health and social well-being.
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Affiliation(s)
- António B Mapossa
- Department of Chemical Engineering, Institute of Applied Materials , University of Pretoria, Lynnwood Road, Pretoria, South Africa.
- UP Institute for Sustainable Malaria Control & MRC Collaborating Centre for Malaria Research, School of Health Systems and Public Health, University of Pretoria, Private Bag X20, Hatfield, 0028, Pretoria, South Africa.
| | - Walter W Focke
- Department of Chemical Engineering, Institute of Applied Materials , University of Pretoria, Lynnwood Road, Pretoria, South Africa
- UP Institute for Sustainable Malaria Control & MRC Collaborating Centre for Malaria Research, School of Health Systems and Public Health, University of Pretoria, Private Bag X20, Hatfield, 0028, Pretoria, South Africa
| | - Robert K Tewo
- Department of Chemical Engineering, Vaal University of Technology, Private Bag X021, 1911, Vanderbijlpark, South Africa
| | - René Androsch
- Interdisciplinary Center for Transfer-oriented Research in Natural Sciences, Martin Luther University Halle-Wittenberg, 06099, Halle/Saale, Germany
| | - Taneshka Kruger
- UP Institute for Sustainable Malaria Control & MRC Collaborating Centre for Malaria Research, School of Health Systems and Public Health, University of Pretoria, Private Bag X20, Hatfield, 0028, Pretoria, South Africa
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Wu W, Li S, Yang M, Lin Y, Zheng K, Akutse KS. Citronellal perception and transmission by Anopheles gambiae s.s. (Diptera: Culicidae) females. Sci Rep 2020; 10:18615. [PMID: 33122679 PMCID: PMC7596511 DOI: 10.1038/s41598-020-75782-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 10/14/2020] [Indexed: 11/08/2022] Open
Abstract
Anopheles gambiae s.s. is a key vector of Plasmodium parasites. Repellents, which may be a promising alternative to pesticides used to control malaria mosquitoes. Although citronellal is a known mosquito repellent, its repellency characteristics are largely unknown. Determining the specific odorant-binding proteins (OBPs) and odorant receptors (ORs) that detect and transfer the citronellal molecule in A. gambiae s.s. will help to define the mode of action of this compound. In this research, we assessed the repellent activity of citronellal in A. gambiae s.s. using a Y-tube olfactory meter, screened candidate citronellal-binding OBPs and ORs using reverse molecular docking, clarified the binding properties of predicted proteins for citronellal using fluorescence competition binding assay. Results showed that citronellal had a dosage effect on repelling A. gambiae s.s.. The 50% repellent rate was determined to be 4.02 nmol. Results of simulated molecular docking showed that the only proteins that bound tightly with citronellal were AgamOBP4 and AgamORC7. Fluorescence competitive binding assays confirmed the simulations. This research determined that citronellal was captured by AgamOBP4 and transmitted to AgamORC7 in A. gambiae s.s.. Our study will be beneficial in the further understanding the repellent mechanism of citronellal against A. gambiae s.s..
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Affiliation(s)
- Weijian Wu
- Institute of Subtropical Agriculture, Fujian Academy of Agriculture Sciences & Zhangzhou Institute of Technology, Zhangzhou, 363001, China
| | - Shanshan Li
- Institute of Subtropical Agriculture, Fujian Academy of Agriculture Sciences & Zhangzhou Institute of Technology, Zhangzhou, 363001, China
| | - Min Yang
- Institute of Subtropical Agriculture, Fujian Academy of Agriculture Sciences & Zhangzhou Institute of Technology, Zhangzhou, 363001, China
| | - Yongwen Lin
- Institute of Subtropical Agriculture, Fujian Academy of Agriculture Sciences & Zhangzhou Institute of Technology, Zhangzhou, 363001, China.
| | - Kaibin Zheng
- Institute of Subtropical Agriculture, Fujian Academy of Agriculture Sciences & Zhangzhou Institute of Technology, Zhangzhou, 363001, China
| | - Komivi Senyo Akutse
- International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya
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Long-Term Mosquito culture with SkitoSnack, an artificial blood meal replacement. PLoS Negl Trop Dis 2020; 14:e0008591. [PMID: 32941432 PMCID: PMC7523998 DOI: 10.1371/journal.pntd.0008591] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 09/29/2020] [Accepted: 07/13/2020] [Indexed: 11/19/2022] Open
Abstract
The reliance on blood is a limiting factor for mass rearing of mosquitoes for Sterile-Insect-Technique (SIT) and other mosquito-based control strategies. To solve this problem, we have developed SkitoSnack, a formulated diet for Aedes aegypti (L) mosquitoes, as an alternative for vertebrate blood. Here we addressed the question if long-term yellow fever mosquito culture with SkitoSnack resulted in changed life history traits and fitness of the offspring compared to blood-raised mosquitoes. We also explored if SkitoSnack is suitable to raise Asian tiger mosquitos, Aedes albopictus (L.), and the human bed bug, Cimex lectularius (L). We measured life history traits for 30th generation SkitoSnack-raised Ae. aegypti and 11th generation SkitoSnack-raised Ae. albopictus, and compared them with control mosquitoes raised on blood only. We compared meal preference, flight performance, and reproductive fitness in Ae. aegypti raised on SkitoSnack or blood. We also offered SkitoSnack to bed bug nymphs. We found that long-term culture with SkitoSnack resulted in mosquitoes with similar life history traits compared to bovine blood-raised mosquitoes in both species we studied. Also, Ae. aegypti mosquitoes raised on SkitoSnack had similar flight performance compared to blood raised mosquitoes, were still strongly attracted by human smell and had equal mating success. Minimal feeding occurred in bed bugs. Our results suggest that long-term culture with the blood-meal replacement SkitoSnack results in healthy, fit mosquitoes. Therefore, artificial diets like SkitoSnack can be considered as a viable alternative for vertebrate blood in laboratory mosquito culture as well as for mosquito mass production for Sterile-Insect-Technique mosquito control interventions. SkitoSnack was not suitable to induce engorgement of bed bugs.
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Iikura H, Takizawa H, Ozawa S, Nakagawa T, Matsui Y, Nambu H. Mosquito repellence induced by tarsal contact with hydrophobic liquids. Sci Rep 2020; 10:14480. [PMID: 32879341 PMCID: PMC7468126 DOI: 10.1038/s41598-020-71406-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 08/14/2020] [Indexed: 11/19/2022] Open
Abstract
Mosquito legs have a unique highly water-repellent surface structure. While being beneficial to mosquitoes, the water-repellence of the tarsi enhances the wettability of hydrophobic substances such as oils. This high wettability induces strong attraction forces on a mosquito’s legs (up to 87% of the mosquito’s weight) towards the oil. We studied the landing behaviour of mosquitoes on oil-coated surfaces and observed that the mosquito contact time was reduced compared to that on hydrophilic-liquid-coated surfaces, suggesting that the oil coating induces an escape response. The observed escape behaviour occurred consistently with several hydrophobic liquids, including silicone oil, which is used globally in personal care products. As the repellent effect is similar to multiple hydrophobic substances, it is likely to be mechanically stimulated owing to the physical properties of the hydrophobic liquids and not due to chemical interactions. On human skin, the contact time was sufficiently short to prevent mosquitoes from starting to blood-feed. The secretion of Hippopotamus amphibius, which has physical properties similar to those of low-viscosity silicone oil, also triggered an escape response, suggesting that it acts as a natural mosquito repellent. Our results are beneficial to develop new, safe, and effective mosquito-repellent technologies.
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Affiliation(s)
- Hiroaki Iikura
- Material Science Research, Kao Corporation, 2-1-3 Bunka, Sumida, Tokyo, 131-8501, Japan. .,Material Science Research, Kao Corporation, 1334 Minato, Wakayama, Wakayama, 640-8580, Japan.
| | - Hiroyuki Takizawa
- Personal Health Care Products Research, Kao Corporation, 2-1-3 Bunka, Sumida, Tokyo, 131-8501, Japan
| | - Satoshi Ozawa
- Material Science Research, Kao Corporation, 1334 Minato, Wakayama, Wakayama, 640-8580, Japan
| | - Takao Nakagawa
- Personal Health Care Products Research, Kao Corporation, 2-1-3 Bunka, Sumida, Tokyo, 131-8501, Japan
| | - Yoshiaki Matsui
- Material Science Research, Kao Corporation, 2-1-3 Bunka, Sumida, Tokyo, 131-8501, Japan.,Material Science Research, Kao Corporation, 1334 Minato, Wakayama, Wakayama, 640-8580, Japan
| | - Hiromi Nambu
- Material Science Research, Kao Corporation, 2-1-3 Bunka, Sumida, Tokyo, 131-8501, Japan.,Material Science Research, Kao Corporation, 1334 Minato, Wakayama, Wakayama, 640-8580, Japan
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13
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Mapossa AB, Sitoe A, Focke WW, Izadi H, du Toit EL, Androsch R, Sungkapreecha C, van der Merwe EM. Mosquito repellent thermal stability, permeability and air volatility. PEST MANAGEMENT SCIENCE 2020; 76:1112-1120. [PMID: 31576645 DOI: 10.1002/ps.5623] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 09/07/2019] [Accepted: 09/16/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND The effectiveness of mosquito repellents, whether applied topically on the skin or released from a wearable device, is determined by the evaporation rate. This is because a repellent has to be present in the form of a vapour in the vicinity of the exposed skin that needs protection. Therefore, gravimetric techniques were used to investigate the direct evaporation of selected liquid repellents, their permeation through polymer films, and their release from a microporous polyethylene matrix. RESULTS Evaporation of a repellent into quiescent air is determined by its air permeability. This is a product of the vapour pressure and the diffusion coefficient, i.e. S A = P A sat D A . It was found that repellents could be ranked in terms of decreasing volatility as: ethyl anthranilate > citriodiol > dimethyl phthalate > N,N-diethyl-meta-toluamide (DEET) > decanoic acid > ethyl butylacetylaminopropionate > Icaridin. Experimental SA values, at 50 °C, ranged from 0.015 ± 0.008 mPa m2 s-1 for the least volatile repellent (Icaridin) to 0.838 ± 0.077 mPa m2 s-1 for the most volatile (ethyl anthranilate). The release rate from microporous polyethylene strands, produced by extrusion-compounding into ice water baths followed a similar ranking. These strands featured an integral skin-like membrane that covered the extruded strands and controlled the release of the repellent at a low effective rate. CONCLUSION The high thermal and thermo-oxidative stability together with the low volatility of the mosquito repellents ethyl butylacetylaminopropionate and Icaridin make them attractive candidates for long-lasting wearable mosquito-repellent devices. Such anklets/bracelets may have utility for outdoor protection against infective mosquito bites in malaria-endemic regions. © 2019 Society of Chemical Industry.
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Affiliation(s)
- António B Mapossa
- Department of Chemical Engineering, Institute of Applied Materials, University of Pretoria, Pretoria, South Africa
- UP Institute for Sustainable Malaria Control & MRC Collaborating Centre for Malaria Research, University of Pretoria, Pretoria, South Africa
| | - Alcides Sitoe
- Department of Chemical Engineering, Institute of Applied Materials, University of Pretoria, Pretoria, South Africa
- UP Institute for Sustainable Malaria Control & MRC Collaborating Centre for Malaria Research, University of Pretoria, Pretoria, South Africa
- Department of Chemistry, Eduardo Mondlane University, Maputo, Mozambique
| | - Walter W Focke
- Department of Chemical Engineering, Institute of Applied Materials, University of Pretoria, Pretoria, South Africa
- UP Institute for Sustainable Malaria Control & MRC Collaborating Centre for Malaria Research, University of Pretoria, Pretoria, South Africa
| | - Homa Izadi
- Department of Chemical Engineering, Institute of Applied Materials, University of Pretoria, Pretoria, South Africa
| | - Elizabeth L du Toit
- Department of Chemical Engineering, Institute of Applied Materials, University of Pretoria, Pretoria, South Africa
| | - René Androsch
- Interdisciplinary Center for Transfer-oriented Research in Natural Sciences, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany
| | - Chanita Sungkapreecha
- Interdisciplinary Center for Transfer-oriented Research in Natural Sciences, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany
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Mitra S, Rodriguez SD, Vulcan J, Cordova J, Chung HN, Moore E, Kandel Y, Hansen IA. Efficacy of Active Ingredients From the EPA 25(B) List in Reducing Attraction of Aedes aegypti (Diptera: Culicidae) to Humans. JOURNAL OF MEDICAL ENTOMOLOGY 2020; 57:477-484. [PMID: 31612914 DOI: 10.1093/jme/tjz178] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Indexed: 06/10/2023]
Abstract
Mosquitoes of the Aedes genus are vectors for dengue, chikungunya, Zika, and yellow fever viruses. Mosquito repellents are an effective way to prevent mosquito bites and reduce the spread of mosquito-borne diseases. In the early 90s, the U.S. Environmental Protection Agency (EPA) published a list of active ingredients that pose minimum risk to human health that can be used as pesticides or repellents without passing the EPA registration process. The present study examined the efficacy of 21 of the active ingredients listed by the EPA 25 (B) exempt list and five commercially available sprays that only contained active ingredients from the EPA 25(B) list in repelling female Aedes aegypti (L.) females. We performed choice bioassays in a controlled laboratory environment, using a Y-tube olfactometer to determine attraction rates of humans to female Ae. aegypti in the presence of one of the 21 active ingredients and five commercially available repellent sprays. We found that cinnamon oil, peppermint oil, spearmint oil, lemongrass oil, and garlic oil reduced mosquito attraction to human odor. Of the five commercial repellent sprays, only one reduced mosquito attraction for up to 30 min in our assay. The EPA 25 (B) list contains active ingredients that under the conditions of our assay repel Ae. aegypti.
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Affiliation(s)
- Soumi Mitra
- Department of Biology, New Mexico State University, Las Cruces, NM
| | | | - Julia Vulcan
- Department of Biology, New Mexico State University, Las Cruces, NM
| | - Joel Cordova
- Department of Biology, New Mexico State University, Las Cruces, NM
| | - Hae-Na Chung
- Department of Biology, New Mexico State University, Las Cruces, NM
| | - Emily Moore
- Department of Biology, New Mexico State University, Las Cruces, NM
| | - Yashoda Kandel
- Department of Biology, New Mexico State University, Las Cruces, NM
| | - Immo A Hansen
- Department of Biology, New Mexico State University, Las Cruces, NM
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15
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Melo VAD, Silva JRS, Corte RL. Personal protective measures of pregnant women against Zika virus infection. Rev Saude Publica 2019; 53:72. [PMID: 31483008 PMCID: PMC6707619 DOI: 10.11606/s1518-8787.2019053001146] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 11/23/2018] [Indexed: 12/25/2022] Open
Abstract
OBJECTIVE To evaluate the adherence of pregnant women to personal protective measures against mosquito bites, recommended by the Ministry of Health, and to investigate the factors associated with the non-adoption of these measures. METHODS We interviewed 177 pregnant women between November 2016 and February 2017 in the 10 basic health units of the municipality of Propriá, state of Sergipe, two located in the rural area and eight in the urban area, during prenatal appointments, to raise information about the use of preventive measures against the vector transmission of Zika virus. Data were analyzed using descriptive statistical methods, chi-square test or Fisher’s exact test, and the odds ratio was calculated. The independent variables were grouped by the analysis of principal components, and the dependents (the use of repellent, mosquito nets, garments, screens and insecticides) were analyzed using the logistic regression method. RESULTS Among the measures recommended by the Ministry of Health, mosquito nets were the most used by pregnant women living in rural areas and with low education level, while the repellents were more used by women in the urban area and with higher education level. Women in a vulnerable socio-economic situation presented a risk 2.4 times higher for not using screens in their homes, 1.9 times higher for not changing clothes and 2.5 times higher for not using repellent than pregnant women in better economic conditions. CONCLUSIONS The socioeconomic status of pregnant women, especially among the less privileged, influenced the use of protective measures against Zika virus, from the purchase of repellent, clothing, insecticides to other resources in the municipality of Propriá, SE.
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Affiliation(s)
| | - José Rodrigo Santos Silva
- Universidade Federal de Sergipe. Programa de Pós-Graduação em Biologia Parasitária. São Cristovão, SE, Brasil.,Universidade Federal de Sergipe. Departamento de Estatística e Ciências Atuariais. Centro de Ciências Exatas e Tecnologia. São Cristovão, SE, Brasil
| | - Roseli La Corte
- Universidade Federal de Sergipe. Programa de Pós-Graduação em Biologia Parasitária. São Cristovão, SE, Brasil.,Universidade Federal de Sergipe. Departamento de Morfologia. Centro de Ciências Biológicas e da Saúde. São Cristovão, SE, Brasil
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16
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Potter A, Jardine A, Morrissey A, Lindsay MDA. Evaluation of a Health Communication Campaign to Improve Mosquito Awareness and Prevention Practices in Western Australia. Front Public Health 2019; 7:54. [PMID: 30941341 PMCID: PMC6433780 DOI: 10.3389/fpubh.2019.00054] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 02/22/2019] [Indexed: 11/13/2022] Open
Abstract
Fight the Bite represents the Department of Health's first attempt to actively raise awareness and improve prevention practices related to mosquitoes in Western Australia (WA). The multi-faceted campaign model involved a range of stakeholders and delivery methods over a 2 year period, achieving a recall rate of 8.2% among 2,500 survey participants. Significant regional differences were noted in campaign exposure, reflecting the variation in mosquito management issues throughout the State, and subsequent engagement by local government. Of those individuals with campaign recall, 43.8% reported an increase in awareness and 27.4% reported a change in behavior, which equated to a 1.7 and 1.2% change across the total survey population, respectively. The results of this study demonstrate that Fight the Bite has significantly improved awareness and prevention practices among those individuals who were exposed to the campaign. This was particularly promising, given the modest budget, resources, and time period over which the campaign was run prior to evaluation. This outcome means that Fight the Bite can be confidently adopted as a proven and standardized but regionally adaptable campaign approach to raising awareness about mosquito avoidance and mosquito-borne diseases by the Department of Health and its stakeholders. Future campaign aims include increasing reach through heightened and sustained promotion of Fight the Bite by both the Department and local government, as well as expanded collaboration with a range of stakeholders within the community.
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Affiliation(s)
- Abbey Potter
- Medical Entomology, Environmental Health Directorate, Public and Aboriginal Health Division, Department of Health, Perth, WA, Australia
| | - Andrew Jardine
- Medical Entomology, Environmental Health Directorate, Public and Aboriginal Health Division, Department of Health, Perth, WA, Australia
| | - Annette Morrissey
- Communications Directorate, Office of the Director General, Department of Health, Perth, WA, Australia
| | - Michael D A Lindsay
- Medical Entomology, Environmental Health Directorate, Public and Aboriginal Health Division, Department of Health, Perth, WA, Australia
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17
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Bernier UR, Kline DL, Vazquez-Abad A, Perry M, Cohnstaedt LW, Gurman P, D’hers S, Elman NM. A combined experimental-computational approach for spatial protection efficacy assessment of controlled release devices against mosquitoes (Anopheles). PLoS Negl Trop Dis 2019; 13:e0007188. [PMID: 30856177 PMCID: PMC6440642 DOI: 10.1371/journal.pntd.0007188] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 03/29/2019] [Accepted: 01/24/2019] [Indexed: 11/19/2022] Open
Abstract
This work describes the use of entomological studies combined with in silico models (computer simulations derived from numerical models) to assess the efficacy of a novel device for controlled release of spatial repellents. Controlled Release Devices (CRDs) were tested with different concentrations of metofluthrin and tested against An. quadrimaculatus mosquitoes using arm-in cage, semi-field, and outdoor studies. Arm-in-cage trials showed an approximate mean values for mosquito knockdown of 40% and mosquito bite reduction of 80% for the optimal metofluthrin formulation for a 15-minute trial. Semi-field outdoor studies showed a mean mortality of a 50% for 24 hour trial and 75% for a 48 hour trial for optimal concentrations. Outdoors studies showed an approximate mean mortality rate of 50% for a 24 hour trial for optimal concentrations. Numerical simulations based on Computational Fluid Dynamics (CFD) were performed in order to obtain spatial concentration profiles for 24 hour and 48 hour periods. Experimental results were correlated with simulation results in order to obtain a functional model that linked mosquito mortality with the estimated spatial concentration for a given period of time. Such correlation provides a powerful insight in predicting the effectiveness of the CRDs as a vector-control tool. While CRDs represent an alternative to current spatial repellent delivery methods, such as coils, candles, electric repellents, and passive emanators based on impregnated strips, the presented method can be applied to any spatial vector control treatment by correlating entomological endpoints, i.e. mortality, with in-silico simulations to predict overall efficacy. The presented work therefore presents a new methodology for improving design, development and deployment of vector-control tools to reduce transmission of vector-borne diseases, including malaria and dengue.
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Affiliation(s)
- Ulrich R. Bernier
- United States Department of Agriculture-Agricultural Research Service, Center for Medical, Agricultural, and Veterinary Entomology, Gainesville, Florida, United States of America
| | - Daniel L. Kline
- United States Department of Agriculture-Agricultural Research Service, Center for Medical, Agricultural, and Veterinary Entomology, Gainesville, Florida, United States of America
| | - Agustin Vazquez-Abad
- Instituto Tecnológico de Buenos Aires (ITBA), Ciudad Autónoma de Buenos Aires, Argentina
| | - Melynda Perry
- Textile Materials Evaluation Team, The US Army Natick Soldier Research, And Development Engineering Center (NSRDEC), Natick, MA, United States of America
| | - Lee W. Cohnstaedt
- United States Department of Agriculture-Agricultural Research Service, The Arthropod-Borne Animal Diseases Research Unit (ABADRU), Manhattan, KS, United States of America
| | - Pablo Gurman
- GearJump Technologies LLC, Brookline, MA, United States of America
| | - Sebastián D’hers
- Instituto Tecnológico de Buenos Aires (ITBA), Ciudad Autónoma de Buenos Aires, Argentina
| | - Noel M. Elman
- GearJump Technologies LLC, Brookline, MA, United States of America
- * E-mail:
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18
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Tangena JAA, Thammavong P, Chonephetsarath S, Logan JG, Brey PT, Lindsay SW. Field evaluation of personal protection methods against outdoor-biting mosquitoes in Lao PDR. Parasit Vectors 2018; 11:661. [PMID: 30558671 PMCID: PMC6296151 DOI: 10.1186/s13071-018-3239-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 11/28/2018] [Indexed: 11/10/2022] Open
Abstract
Background Protecting people outdoors against mosquito-borne diseases is a major challenge. Here we compared commercially available personal protection methods to identify the most effective method for outdoor use in northern Lao PDR. Methods From June to August 2016 the protective efficacy of treatments were compared in a secondary forest during the afternoon and a village during the evening. Comparisons were made using a replicated Latin square design between: (i) short permethrin-treated overalls; (ii) long permethrin-treated overalls; (iii) short untreated overalls with para-menthane-3,8-diol (PMD) applied topically; (iv) short permethrin-treated overalls plus PMD applied topically; (v) short untreated overalls with metofluthrin coils in a metal casing worn on a belt; and (vi) long untreated overalls. Short untreated overalls served as the control. Cone tests were conducted on the treated and untreated fabric before and after field experiments. A questionnaire survey was used to measure social acceptability. Results Mosquito coils in a metal casing worn on a belt resulted in 92.3% (95% confidence interval, CI: 88.9–94.6%). landing protection from female mosquitoes in the afternoon and 68.8% (95% CI: 41.7–83.3%) protection in the evening compared to short untreated clothing. PMD was protective both when combined with short permethrin-treated overalls (afternoon, 68.2%, 95% CI: 52.6–78.7%; evening, 52.3%, 95% CI: 33.8–65.7%) and when used in combination with short untreated overalls (afternoon, 55.0%, 95% CI: 41.7–65.2%; evening, 25.2%, 95% CI: 9.4–38.2%). Whilst long permethrin-treated overalls were protective (afternoon, 61.1%, 95% CI: 51.4–68.8%; evening, 43.0%, 95% CI: 25.5–56.4%), short permethrin-treated overalls and long untreated overalls were not. Exposure to new permethrin-treated fabric in cone tests resulted in 25.0% (95% CI, 17.8–32.2%) and 26.2% (95% CI 16.7–35.8%) mortality for susceptible Ae. albopictus and susceptible Ae. aegypti, respectively. There was a loss of efficacy of permethrin-treated clothing after use in the field, with 3 min knockdown rates of Ae. albopictus and 1 h knockdown of Ae. aegypti decreasing over time. Participants considered all treatments acceptable. Conclusions The portable mosquito coils were highly protective against outdoor biting mosquitoes, although there are safety concerns related to its use. The combination of permethrin-treated clothing and PMD repellent represent an alternative treatment for protection against outdoor-biting mosquitoes. Electronic supplementary material The online version of this article (10.1186/s13071-018-3239-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Julie-Anne A Tangena
- Medical Entomology & Biology of Disease Vectors Laboratory, Institut Pasteur du Laos, Vientiane, Lao PDR.
| | - Phoutmany Thammavong
- Medical Entomology & Biology of Disease Vectors Laboratory, Institut Pasteur du Laos, Vientiane, Lao PDR
| | - Somsanith Chonephetsarath
- Medical Entomology & Biology of Disease Vectors Laboratory, Institut Pasteur du Laos, Vientiane, Lao PDR
| | - James G Logan
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK.,ARCTEC, London School of Hygiene and Tropical Medicine, London, UK
| | - Paul T Brey
- Medical Entomology & Biology of Disease Vectors Laboratory, Institut Pasteur du Laos, Vientiane, Lao PDR
| | - Steve W Lindsay
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK.,Department of Biosciences, Durham University, Durham, UK
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Moore EL, Scott MA, Rodriguez SD, Mitra S, Vulcan J, Cordova JJ, Chung HN, Linhares Lino de Souza D, Gonzales KK, Hansen IA. An online survey of personal mosquito-repellent strategies. PeerJ 2018; 6:e5151. [PMID: 30002979 PMCID: PMC6034598 DOI: 10.7717/peerj.5151] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 06/12/2018] [Indexed: 12/21/2022] Open
Abstract
Background Mosquito repellents can be an effective method for personal protection against mosquito bites that are a nuisance and carry the risk of transmission of mosquito-borne pathogens like plasmodia, dengue virus, chikungunya virus, and Zika virus. A multitude of commercially available products are currently on the market, some of them highly effective while others have low or no efficacy. Many home remedies of unknown efficacy are also widely used. Methods We conducted a survey study to determine what kind of mosquito repellents and other mosquito control strategies people use. Our online survey was focused on unconventional methods and was answered by 5,209 participants. Results The majority of participants resided in the United States, were female (67%), had higher education (81% had a university degree), and were 18 to 37 years old (50%). The most commonly used repellent was DEET spray (48%), followed closely by citronella candles (43%) and ‘natural’ repellent sprays (36%). We collected a plethora of home remedies and other strategies people use that warrant further research into their effectiveness. Discussion Our study lays the foundation for future research in alternative, unconventional methods to repel mosquitoes that may be culturally acceptable and accessible for people.
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Affiliation(s)
- Emily Lucille Moore
- Department of Biology, New Mexico State University, Las Cruces, NM, United States of America
| | - Mary Alice Scott
- Department of Anthropology, New Mexico State University, Las Cruces, NM, United States of America
| | - Stacy Deadra Rodriguez
- Department of Biology, New Mexico State University, Las Cruces, NM, United States of America
| | - Soumi Mitra
- Department of Biology, New Mexico State University, Las Cruces, NM, United States of America
| | - Julia Vulcan
- Department of Biology, New Mexico State University, Las Cruces, NM, United States of America
| | - Joel Javierla Cordova
- Department of Biology, New Mexico State University, Las Cruces, NM, United States of America
| | - Hae-Na Chung
- Department of Biology, New Mexico State University, Las Cruces, NM, United States of America
| | | | - Kristina Kay Gonzales
- Department of Biology, New Mexico State University, Las Cruces, NM, United States of America
| | - Immo Alex Hansen
- Department of Biology, New Mexico State University, Las Cruces, NM, United States of America.,Institute for Applied Biosciences, New Mexico State University, Las Cruces, NM, United States of America
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Singh RK, Dhama K, Khandia R, Munjal A, Karthik K, Tiwari R, Chakraborty S, Malik YS, Bueno-Marí R. Prevention and Control Strategies to Counter Zika Virus, a Special Focus on Intervention Approaches against Vector Mosquitoes-Current Updates. Front Microbiol 2018; 9:87. [PMID: 29472902 PMCID: PMC5809424 DOI: 10.3389/fmicb.2018.00087] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Accepted: 01/15/2018] [Indexed: 12/31/2022] Open
Abstract
Zika virus (ZIKV) is the most recent intruder that acquired the status of global threat creating panic and frightening situation to public owing to its rapid spread, attaining higher virulence and causing complex clinical manifestations including microcephaly in newborns and Guillain Barré Syndrome. Alike other flaviviruses, the principal mode of ZIKV transmission is by mosquitoes. Advances in research have provided reliable diagnostics for detecting ZIKV infection, while several drug/therapeutic targets and vaccine candidates have been identified recently. Despite these progresses, currently there is neither any effective drug nor any vaccine available against ZIKV. Under such circumstances and to tackle the problem at large, control measures of which mosquito population control need to be strengthened following appropriate mechanical, chemical, biological and genetic control measures. Apart from this, several other known modes of ZIKV transmission which have gained importance in recent past such as intrauterine, sexual intercourse, and blood-borne spread need to be checked and kept under control by adopting appropriate precautions and utmost care during sexual intercourse, blood transfusion and organ transplantation. The virus inactivation by pasteurization, detergents, chemicals, and filtration can effectively reduce viral load in plasma-derived medicinal products. Added to this, strengthening of the surveillance and monitoring of ZIKV as well as avoiding travel to Zika infected areas would aid in keeping viral infection under check. Here, we discuss the salient advances in the prevention and control strategies to combat ZIKV with a focus on highlighting various intervention approaches against the vector mosquitoes of this viral pathogen along with presenting an overview regarding human intervention measures to counter other modes of ZIKV transmission and spread. Additionally, owing to the success of vaccines for a number of infections globally, a separate section dealing with advances in ZIKV vaccines and transmission blocking vaccines has also been included.
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Affiliation(s)
- Raj K Singh
- ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, India
| | - Kuldeep Dhama
- Division of Pathology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, India
| | - Rekha Khandia
- Department of Biochemistry and Genetics, Barkatullah University, Bhopal, India
| | - Ashok Munjal
- Department of Biochemistry and Genetics, Barkatullah University, Bhopal, India
| | - Kumaragurubaran Karthik
- Central University Laboratory, Tamil Nadu Veterinary and Animal Sciences University, Chennai, India
| | - Ruchi Tiwari
- Department of Veterinary Microbiology and Immunology, College of Veterinary Sciences, UP Pandit Deen Dayal Upadhayay Pashu Chikitsa Vigyan Vishwavidyalay Evum Go-Anusandhan Sansthan, Mathura, India
| | - Sandip Chakraborty
- Department of Veterinary Microbiology, College of Veterinary Sciences and Animal Husbandry, Agartala, India
| | - Yashpal S Malik
- Division of Biological Standardization, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, India
| | - Rubén Bueno-Marí
- Laboratorios Lokímica, Departamento de Investigación y Desarrollo (I+D), Valencia, Spain
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Dutta S, Celestine MJ, Khanal S, Huddleston A, Simms C, Arca JF, Mitra A, Heller L, Kraj PJ, Ledizet M, Anderson JF, Neelakanta G, Holder AA, Sultana H. Coordination of different ligands to copper(II) and cobalt(III) metal centers enhances Zika virus and dengue virus loads in both arthropod cells and human keratinocytes. Biochim Biophys Acta Gen Subj 2017; 1862:40-50. [PMID: 29030319 DOI: 10.1016/j.bbagen.2017.10.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 09/01/2017] [Accepted: 10/06/2017] [Indexed: 11/17/2022]
Abstract
Trace elements such as copper and cobalt have been associated with virus-host interactions. However, studies to show the effect of conjugation of copper(II) or cobalt(III) metal centers to thiosemicarbazone ligand(s) derived from either food additives or mosquito repellent such as 2-acetylethiazole or citral, respectively, on Zika virus (ZIKV) or dengue virus (serotype 2; DENV2) infections have not been explored. In this study, we show that four compounds comprising of thiosemicarbazone ligand derived from 2-acetylethiazole viz., (E)-N-ethyl-2-[1-(thiazol-2-yl)ethylidene]hydrazinecarbothioamide (acetylethTSC) (compound 1), a copper(II) complex with acetylethTSC as a ligand (compound 2), a thiosemicarbazone ligand-derived from citral (compound 3) and a cobalt(III) complex with a citral-thiosemicarbazone ligand (compound 4) increased DENV2 and ZIKV replication in both mosquito C6/36 cells and human keratinocytes (HaCaT cells). Treatment of both cell lines with compounds 2 or 4 showed increased dengue viral titers at all three tested doses. Enhanced dengue viral plaque formation was also noted at the tested dose of 100μM, suggesting higher production of infectious viral particles. Treatment with the compounds 2 or 4 enhanced ZIKV and DENV2 RNA levels in HeLa cell line and primary cultures of mouse bone marrow derived dendritic cells. Also, pre- or post treatments with conjugated compounds 2 or 4 showed higher loads of ZIKV or DENV2 envelope (E) protein in HaCaT cells. No changes in loads of E-protein were found in ZIKV-infected C6/36 cells, when compounds were treated after infection. In addition, we tested bis(1,10-phenanthroline)copper(II) chloride ([Cu(phen)2]Cl2, (compound 5) and tris(1,10-phenanthroline)cobalt(III) chloride ([Co(phen)3]Cl3, (compound 6) that also showed enhanced DENV2 loads. Also, we found that copper(II) chloride dehydrate (CuCl2·2H2O) or cobalt(II) chloride hexahydrate (CoCl2·6H2O) alone had no effects as "free" cations. Taken together, these findings suggest that use of Cu(II) or Co(III) conjugation to organic compounds, in insect repellents and/or food additives could enhance DENV2/ZIKV loads in human cells and perhaps induce pathogenesis in infected individuals or individuals pre-exposed to such conjugated complexes. IMPORTANCE Mosquito-borne diseases are of great concern to the mankind. Use of chemicals/repellents against mosquito bites and transmission of microbes has been the topic of interest for many years. Here, we show that thiosemicarbazone ligand(s) derived from 2-acetylethiazole or citral or 1,10-phenanthroline upon conjugation with copper(II) or cobalt(III) metal centers enhances dengue virus (serotype 2; DENV2) and/or Zika virus (ZIKV) infections in mosquito, mouse and human cells. Enhanced ZIKV/DENV2 capsid mRNA or envelope protein loads were evident in mosquito cells and human keratinocytes, when treated with compounds before/after infections. Also, treatment with copper(II) or cobalt(III) conjugated compounds increased viral titers and number of plaque formations. These studies suggest that conjugation of compounds in repellents/essential oils/natural products/food additives with copper(II) or cobalt(III) metal centers may not be safe, especially in tropical and subtropical places, where several dengue infection cases and deaths are reported annually or in places with increased ZIKV caused microcephaly.
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Affiliation(s)
- Shovan Dutta
- Department of Biological Sciences, Old Dominion University, Norfolk, VA, USA
| | - Michael J Celestine
- Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, VA, USA
| | - Supreet Khanal
- Department of Biological Sciences, Old Dominion University, Norfolk, VA, USA
| | - Alexis Huddleston
- Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, VA, USA
| | - Colin Simms
- Department of Biological Sciences, Old Dominion University, Norfolk, VA, USA
| | - Jessa Faye Arca
- Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, VA, USA
| | - Amlan Mitra
- Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, VA, USA
| | - Loree Heller
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, USA; School of Medical Diagnostic & Translational Sciences College of Health Sciences, Old Dominion University, Norfolk, VA, USA
| | - Piotr J Kraj
- Department of Biological Sciences, Old Dominion University, Norfolk, VA, USA; Center for Molecular Medicine, Old Dominion University, Norfolk, VA, USA
| | | | - John F Anderson
- The Connecticut Agricultural Experiment Station, New Haven, CT, USA
| | - Girish Neelakanta
- Department of Biological Sciences, Old Dominion University, Norfolk, VA, USA; Center for Molecular Medicine, Old Dominion University, Norfolk, VA, USA
| | - Alvin A Holder
- Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, VA, USA
| | - Hameeda Sultana
- Department of Biological Sciences, Old Dominion University, Norfolk, VA, USA; Center for Molecular Medicine, Old Dominion University, Norfolk, VA, USA.
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Erratum. JOURNAL OF INSECT SCIENCE (ONLINE) 2017; 17:3084726. [PMID: 28365768 PMCID: PMC5437872 DOI: 10.1093/jisesa/iex016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
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