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St Laurent B, Burton TA, Zubaidah S, Miller HC, Asih PB, Baharuddin A, Kosasih S, Shinta, Firman S, Hawley WA, Burkot TR, Syafruddin D, Sukowati S, Collins FH, Lobo NF. Host attraction and biting behaviour of Anopheles mosquitoes in South Halmahera, Indonesia. Malar J 2017; 16:310. [PMID: 28764710 PMCID: PMC5540179 DOI: 10.1186/s12936-017-1950-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 07/20/2017] [Indexed: 11/10/2022] Open
Abstract
Background Indonesia is home to a variety of malaria vectors whose specific bionomic traits remain largely uncharacterized. Species-specific behaviours, such as host feeding preferences, impact the dynamics of malaria transmission and the effectiveness of vector control interventions. Methods To examine species-specific host attraction and feeding behaviours, a Latin square design was used to compare Anopheles mosquitoes attracted to human, cow, and goat-baited tents. Anopheles mosquitoes were collected hourly from the inside walls of each baited tent. Species were morphologically and then molecularly identified using rDNA ITS2 sequences. The head and thorax of individual specimens were analysed for Plasmodium DNA using PCR. Bloodmeals were identified using a multiplex PCR. Results A total of 1024, 137, and 74 Anopheles were collected over 12 nights in cow, goat, and human-baited tents, respectively. The species were identified as Anopheles kochi, Anopheles farauti s.s., Anopheles hackeri, Anopheles hinesorum, Anopheles indefinitus, Anopheles punctulatus, Anopheles tessellatus, Anopheles vagus, and Anopheles vanus, many of which are known to transmit human malaria. Molecular analysis of blood meals revealed a high level of feeding on multiple host species in a single night. Anopheles kochi, An. indefinitus, and An. vanus were infected with Plasmodium vivax at rates comparable to primary malaria vectors. Conclusions The species distributions of Anopheles mosquitoes attracted to human, goat, and cow hosts were similar. Eight of nine sporozoite positive samples were captured with animal-baited traps, indicating that even predominantly zoophilic mosquitoes may be contributing to malaria transmission. Multiple host feeding and flexibility in blood feeding behaviour have important implications for malaria transmission, malaria control, and the effectiveness of intervention and monitoring methods, particularly those that target human-feeding vectors. Electronic supplementary material The online version of this article (doi:10.1186/s12936-017-1950-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Brandyce St Laurent
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA. .,Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
| | - Timothy A Burton
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA
| | - Siti Zubaidah
- Eijkman Institute for Molecular Biology, Jakarta, Indonesia
| | - Helen C Miller
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA
| | - Puji B Asih
- Eijkman Institute for Molecular Biology, Jakarta, Indonesia
| | | | - Sully Kosasih
- Eijkman Institute for Molecular Biology, Jakarta, Indonesia
| | - Shinta
- National Institute of Health Research and Development, Jakarta, Indonesia
| | - Saya Firman
- National Institute of Health Research and Development, Jakarta, Indonesia
| | - William A Hawley
- Centers for Disease Control and Prevention, Atlanta, GA, USA.,Unicef, Jakarta, Indonesia
| | - Thomas R Burkot
- Centers for Disease Control and Prevention, Atlanta, GA, USA.,Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Australia
| | - Din Syafruddin
- Eijkman Institute for Molecular Biology, Jakarta, Indonesia
| | - Supratman Sukowati
- National Institute of Health Research and Development, Jakarta, Indonesia
| | - Frank H Collins
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA
| | - Neil F Lobo
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA
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Lyimo IN, Kessy ST, Mbina KF, Daraja AA, Mnyone LL. Ivermectin-treated cattle reduces blood digestion, egg production and survival of a free-living population of Anopheles arabiensis under semi-field condition in south-eastern Tanzania. Malar J 2017; 16:239. [PMID: 28587669 PMCID: PMC5461717 DOI: 10.1186/s12936-017-1885-x] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 05/30/2017] [Indexed: 01/26/2023] Open
Abstract
Background Anopheles arabiensis feed on cattle and contributes to residual transmission of malaria in areas with high coverage of long-lasting insecticide-treated nets and indoor residual spraying in East Africa. This study aimed to evaluate the effects of ivermectin-treated cattle as a complementary vector control tool against population of An. arabiensis under the semi-field conditions in south-eastern Tanzania. Methods The free-living population of An. arabiensis was allowed to forage on untreated or ivermectin-treated cattle in alternating nights within the semi-field system in south-eastern Tanzania. Fresh blood fed mosquitoes were collected in the morning using mouth aspirators and assessed for their blood meal digestion, egg production, and survivorship. The residual activity of ivermectin-treated cattle was also determined by exposing mosquitoes to the same treatments after every 2 days until day 21 post-treatments. These experiments were replicated 3 times using different individual cattle. Results Overall, the ivermectin-treated cattle reduced blood meal digestion in the stomach of An. arabiensis, and their subsequent egg production and survival over time. The ivermectin-treated cattle halved blood meal digestion in mosquitoes, but reduced their egg production for up to 15 days. The ivermectin-treated cattle reduced the survival, and median survival times (1–3 days) of An. arabiensis than control cattle. The daily mortality rates of mosquitoes fed on ivermectin-treated cattle increased by five-fold relative to controls in the first week, and it gradually declined up to 21 days after treatment. Conclusion This study demonstrates that long-lasting effects of ivermectin-treated cattle on egg production and survival of An. arabiensis may sustainably suppress their vector density, and reduce residual transmission of malaria. This study suggests that ivermectin-treated non-lactating cattle (i.e. calves, heifers and bulls) could be suitable option for large-scale malaria vector control without limiting consumption of milk and meat by communities in rural settings. Furthermore, simulation models are underway to predict the impact of ivermectin-treated cattle alone, or in combination with LLIN/IRS, the frequency of treatment, and their coverage required to significantly suppress population of An. arabiensis and reduce residual transmission of malaria.
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Affiliation(s)
- Issa N Lyimo
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Off Mlabani Passage, P.O.BOX 53, Ifakara, Morogoro, United Republic of Tanzania.
| | - Stella T Kessy
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Off Mlabani Passage, P.O.BOX 53, Ifakara, Morogoro, United Republic of Tanzania
| | - Kasian F Mbina
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Off Mlabani Passage, P.O.BOX 53, Ifakara, Morogoro, United Republic of Tanzania
| | - Ally A Daraja
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Off Mlabani Passage, P.O.BOX 53, Ifakara, Morogoro, United Republic of Tanzania
| | - Ladslaus L Mnyone
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Off Mlabani Passage, P.O.BOX 53, Ifakara, Morogoro, United Republic of Tanzania.,Pest Management Centre, Sokoine University of Agriculture, Morogoro, Tanzania.,School of Public Health, University of the Witwatersrand, Parktown, Republic of South Africa
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53
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How to Contain Artemisinin- and Multidrug-Resistant Falciparum Malaria. Trends Parasitol 2017; 33:353-363. [DOI: 10.1016/j.pt.2017.01.004] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2016] [Revised: 11/18/2016] [Accepted: 01/05/2017] [Indexed: 11/20/2022]
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Abstract
As the world begins to realize the very real prospect of eliminating malaria as a public health problem globally, the scientific community is acutely aware that novel and innovative new tools will be required if that lofty goal is to be accomplished. Moreover, the need for comprehensive, integrated products and interventions is being recognized in order for the critical 'final steps' toward elimination to be taken successfully. Failure to take these crucial last steps have dogged all past global disease elimination programmes, except for smallpox. The success of ivermectin in driving two of the most devastating and disfiguring neglected tropical diseases (NTD) to the brink of elimination has been well documented. The drug also bestows immeasurable non-target benefits, increasing the health and socioeconomic prospects of all communities where mass drug administration (MDA) has been carried out. Ivermectin kills a variety of parasites and insects, including the Anopheline vectors of malaria parasites. In view of long-standing MDA programmes, increasing attention is now being paid to the potential offered by re-formulating and re-purposing ivermectin to function as a feed-though mosquitocidal tool. This will provide a comprehensively beneficial weapon, for the anti-malarial armamentarium, as well as for probably improving the impact on existing target diseases. Prospects currently look highly promising, especially as the drug is already proven to be extremely safe for human use. However, for maximum impact, detailed analysis of various analogues of the unique ivermectin, as well as the parent avermectin compounds, will need to be undertaken. 'Ivermectin' comprises an imprecise mix of two compounds, both of which are potent anthelmintics. Yet recently, it has been confirmed that only the minor of the two component compounds is molluscicidal. Further structure activity relationship studies may well identify the analogue, analogues or combination thereof best suited for use in a concerted initiative to simultaneously tackle malaria and other NTD in poly-parasitized communities.
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Affiliation(s)
- Satoshi Ōmura
- Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641, Japan
| | - Andy Crump
- Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641, Japan.
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55
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Chaccour C, Hammann F, Rabinovich NR. Ivermectin to reduce malaria transmission I. Pharmacokinetic and pharmacodynamic considerations regarding efficacy and safety. Malar J 2017; 16:161. [PMID: 28434401 PMCID: PMC5402169 DOI: 10.1186/s12936-017-1801-4] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 04/06/2017] [Indexed: 02/07/2023] Open
Abstract
Ivermectin is an endectocide that has been used broadly in single dose community campaigns for the control of onchocerciasis and lymphatic filariasis for more than 30 years. There is now interest in the potential use of ivermectin regimens to reduce malaria transmission, envisaged as community-wide campaigns tailored to transmission patterns and as complement of the local vector control programme. The development of new ivermectin regimens or other novel endectocides will require integrated development of the drug in the context of traditional entomological tools and endpoints. This document examines the main pharmacokinetic and pharmacodynamic parameters of the medicine and their potential influence on its vector control efficacy and safety at population level. This information could be valuable for trial design and clinical development into regulatory and policy pathways.
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Affiliation(s)
- Carlos Chaccour
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain. .,Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique. .,Instituto de Salud Tropical Universidad de Navarra, Pamplona, Spain.
| | - Felix Hammann
- Division of Clinical Pharmacology & Toxicology, University Hospital Basel, Basel, Switzerland
| | - N Regina Rabinovich
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain.,Harvard T.H. Chan School of Public Health, Boston, USA
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56
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Chaccour C, Rabinovich NR. Ivermectin to reduce malaria transmission II. Considerations regarding clinical development pathway. Malar J 2017; 16:166. [PMID: 28434405 DOI: 10.1186/s12936-017-1802-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 04/06/2017] [Indexed: 12/31/2022] Open
Abstract
The development of ivermectin as a complementary vector control tool will require good quality evidence. This paper reviews the different eco-epidemiological contexts in which mass drug administration with ivermectin could be useful. Potential scenarios and pharmacological strategies are compared in order to help guide trial design. The rationale for a particular timing of an ivermectin-based tool and some potentially useful outcome measures are suggested.
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Affiliation(s)
- Carlos Chaccour
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic, Universitat de Barcelona, Barcelona, Spain. .,Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique. .,Instituto de Salud Tropical Universidad de Navarra, Pamplona, Spain.
| | - N Regina Rabinovich
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic, Universitat de Barcelona, Barcelona, Spain.,Harvard T.H. Chan School of Public Health, Boston, MA, USA
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57
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Crump A. Ivermectin: enigmatic multifaceted 'wonder' drug continues to surprise and exceed expectations. J Antibiot (Tokyo) 2017; 70:495-505. [PMID: 28196978 DOI: 10.1038/ja.2017.11] [Citation(s) in RCA: 114] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 11/28/2016] [Accepted: 12/03/2016] [Indexed: 12/12/2022]
Abstract
Over the past decade, the global scientific community have begun to recognize the unmatched value of an extraordinary drug, ivermectin, that originates from a single microbe unearthed from soil in Japan. Work on ivermectin has seen its discoverer, Satoshi Ōmura, of Tokyo's prestigious Kitasato Institute, receive the 2014 Gairdner Global Health Award and the 2015 Nobel Prize in Physiology or Medicine, which he shared with a collaborating partner in the discovery and development of the drug, William Campbell of Merck & Co. Incorporated. Today, ivermectin is continuing to surprise and excite scientists, offering more and more promise to help improve global public health by treating a diverse range of diseases, with its unexpected potential as an antibacterial, antiviral and anti-cancer agent being particularly extraordinary.
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Affiliation(s)
- Andy Crump
- Graduate School of Infection Control Sciences, Kitasato University, Minato-Ku, Japan
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58
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Inhibition of Plasmodium Liver Infection by Ivermectin. Antimicrob Agents Chemother 2017; 61:AAC.02005-16. [PMID: 27895022 PMCID: PMC5278742 DOI: 10.1128/aac.02005-16] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 11/18/2016] [Indexed: 12/29/2022] Open
Abstract
Avermectins are powerful endectocides with an established potential to reduce the incidence of vector-borne diseases. Here, we show that several avermectins inhibit the hepatic stage of Plasmodium infection in vitro. Notably, ivermectin potently inhibits liver infection in vivo by impairing parasite development inside hepatocytes. This impairment has a clear impact on the ensuing blood stage parasitemia, reducing disease severity and enhancing host survival. Ivermectin has been proposed as a tool to control malaria transmission because of its effects on the mosquito vector. Our study extends the effect of ivermectin to the early stages of mammalian host infection and supports the inclusion of this multipurpose drug in malaria control strategies.
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59
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Chaccour CJ, Rabinovich NR. Oral, Slow-Release Ivermectin: Biting Back at Malaria Vectors. Trends Parasitol 2017; 33:156-158. [PMID: 28065670 DOI: 10.1016/j.pt.2016.12.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 12/09/2016] [Indexed: 10/20/2022]
Abstract
Bellinger and colleagues offer an elegant twist for a promising new tool against malaria. This formulation is designed to release ivermectin, a mosquito-killing drug for 10 days after a single oral dose. This could reduce the vector population and serve as a complementary tool for malaria elimination.
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Affiliation(s)
- Carlos J Chaccour
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Spain; Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique; Instituto de Salud Tropical Universidad de Navarra, Pamplona, Spain.
| | - N Regina Rabinovich
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Spain; Harvard T.H. Chan School of Public Health, Boston, USA
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60
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Alout H, Foy BD. Ivermectin: a complimentary weapon against the spread of malaria? Expert Rev Anti Infect Ther 2016; 15:231-240. [PMID: 27960597 DOI: 10.1080/14787210.2017.1271713] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
INTRODUCTION Ivermectin has transformed the treatment of parasitic diseases and led to incommensurable benefits to humans and animals. Ivermectin is effective in treating several neglected infectious diseases and recently it has been shown to reduce malaria parasite transmission. Areas covered: Malaria control strategies could benefit from the addition of ivermectin to interrupt the transmission cycle if it is a long lasting formulation or repeatedly administered. In turn, this will help also to control neglected infectious diseases where the elimination goal has been slower to achieve. Despite the relevance of using ivermectin for integrated and sustained disease control, there are still essential questions that remain to be addressed about safety and practicality. The efficacy in various malaria ecologies and the interaction between control tools, either drugs or insecticides, are also important to assess. Expert commentary: Overlapping distribution of several infectious diseases reveals the benefit of integrating control programs against several infectious diseases into one strategy for cost effectiveness and to reach the elimination goals. The use of ivermectin to control malaria transmission will necessitate development and testing of long-lasting formulations or repeated treatments, and implementation of these treatments with other disease control tools may increase the chance of successful and sustained control.
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Affiliation(s)
- Haoues Alout
- a Microbiology, Immunology and Pathology & Arthropod-borne Infectious Diseases Laboratory , Colorado State University , Fort Collins , CO , USA
| | - Brian D Foy
- a Microbiology, Immunology and Pathology & Arthropod-borne Infectious Diseases Laboratory , Colorado State University , Fort Collins , CO , USA
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61
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Smit MR, Ochomo E, Aljayyoussi G, Kwambai T, Abong'o B, Bayoh N, Gimnig J, Samuels A, Desai M, Phillips-Howard PA, Kariuki S, Wang D, Ward S, Ter Kuile FO. Efficacy and Safety of High-Dose Ivermectin for Reducing Malaria Transmission (IVERMAL): Protocol for a Double-Blind, Randomized, Placebo-Controlled, Dose-Finding Trial in Western Kenya. JMIR Res Protoc 2016; 5:e213. [PMID: 27856406 PMCID: PMC5133431 DOI: 10.2196/resprot.6617] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 10/17/2016] [Accepted: 10/18/2016] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Innovative approaches are needed to complement existing tools for malaria elimination. Ivermectin is a broad spectrum antiparasitic endectocide clinically used for onchocerciasis and lymphatic filariasis control at single doses of 150 to 200 mcg/kg. It also shortens the lifespan of mosquitoes that feed on individuals recently treated with ivermectin. However, the effect after a 150 to 200 mcg/kg oral dose is short-lived (6 to 11 days). Modeling suggests higher doses, which prolong the mosquitocidal effects, are needed to make a significant contribution to malaria elimination. Ivermectin has a wide therapeutic index and previous studies have shown doses up to 2000 mcg/kg (ie, 10 times the US Food and Drug Administration approved dose) are well tolerated and safe; the highest dose used for onchocerciasis is a single dose of 800 mcg/kg. OBJECTIVE The aim of this study is to determine the safety, tolerability, and efficacy of ivermectin doses of 0, 300, and 600 mcg/kg/day for 3 days, when provided with a standard 3-day course of the antimalarial dihydroartemisinin-piperaquine (DP), on mosquito survival. METHODS This is a double-blind, randomized, placebo-controlled, parallel-group, 3-arm, dose-finding trial in adults with uncomplicated malaria. Monte Carlo simulations based on pharmacokinetic modeling were performed to determine the optimum dosing regimens to be tested. Modeling showed that a 3-day regimen of 600 mcg/kg/day achieved similar median (5 to 95 percentiles) maximum drug concentrations (Cmax) of ivermectin to a single of dose of 800 mcg/kg, while increasing the median time above the lethal concentration 50% (LC50, 16 ng/mL) from 1.9 days (1.0 to 5.7) to 6.8 (3.8 to 13.4) days. The 300 mcg/kg/day dose was chosen at 50% of the higher dose to allow evaluation of the dose response. Mosquito survival will be assessed daily up to 28 days in laboratory-reared Anopheles gambiae s.s. populations fed on patients' blood taken at days 0, 2 (Cmax), 7 (primary outcome), 10, 14, 21, and 28 after the start of treatment. Safety outcomes include QT-prolongation and mydriasis. The trial will be conducted in 6 health facilities in western Kenya and requires a sample size of 141 participants (47 per arm). Sub-studies include (1) rich pharmacokinetics and (2) direct skin versus membrane feeding assays. RESULTS Recruitment started July 20, 2015. Data collection was completed July 2, 2016. Unblinding and analysis will commence once the database has been completed, cleaned, and locked. CONCLUSIONS High-dose ivermectin, if found to be safe and well tolerated, might offer a promising new tool for malaria elimination.
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Affiliation(s)
- Menno R Smit
- Liverpool School of Tropical Medicine (LSTM), Liverpool, United Kingdom
| | - Eric Ochomo
- Centre for Global Health Research, Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
| | | | - Titus Kwambai
- Centre for Global Health Research, Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
- Kisumu County, Kenya Ministry of Health (MoH), Kisumu, Kenya
| | - Bernard Abong'o
- Centre for Global Health Research, Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
| | - Nabie Bayoh
- Division of Parasitic Diseases and Malaria, Center for Global Health, U.S. Centers for Disease Control and Prevention (CDC), Atlanta, GA, United States
| | - John Gimnig
- Division of Parasitic Diseases and Malaria, Center for Global Health, U.S. Centers for Disease Control and Prevention (CDC), Atlanta, GA, United States
| | - Aaron Samuels
- Division of Parasitic Diseases and Malaria, Center for Global Health, U.S. Centers for Disease Control and Prevention (CDC), Atlanta, GA, United States
| | - Meghna Desai
- Division of Parasitic Diseases and Malaria, Center for Global Health, U.S. Centers for Disease Control and Prevention (CDC), Atlanta, GA, United States
| | | | - Simon Kariuki
- Centre for Global Health Research, Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
| | - Duolao Wang
- Liverpool School of Tropical Medicine (LSTM), Liverpool, United Kingdom
| | - Steve Ward
- Liverpool School of Tropical Medicine (LSTM), Liverpool, United Kingdom
| | - Feiko O Ter Kuile
- Liverpool School of Tropical Medicine (LSTM), Liverpool, United Kingdom
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62
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Swale DR, Engers DW, Bollinger SR, Gross A, Inocente EA, Days E, Kanga F, Johnson RM, Yang L, Bloomquist JR, Hopkins CR, Piermarini PM, Denton JS. An insecticide resistance-breaking mosquitocide targeting inward rectifier potassium channels in vectors of Zika virus and malaria. Sci Rep 2016; 6:36954. [PMID: 27849039 PMCID: PMC5111108 DOI: 10.1038/srep36954] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 10/19/2016] [Indexed: 01/01/2023] Open
Abstract
Insecticide resistance is a growing threat to mosquito control programs around the world, thus creating the need to discover novel target sites and target-specific compounds for insecticide development. Emerging evidence suggests that mosquito inward rectifier potassium (Kir) channels represent viable molecular targets for developing insecticides with new mechanisms of action. Here we describe the discovery and characterization of VU041, a submicromolar-affinity inhibitor of Anopheles (An.) gambiae and Aedes (Ae.) aegypti Kir1 channels that incapacitates adult female mosquitoes from representative insecticide-susceptible and -resistant strains of An. gambiae (G3 and Akron, respectively) and Ae. aegypti (Liverpool and Puerto Rico, respectively) following topical application. VU041 is selective for mosquito Kir channels over several mammalian orthologs, with the exception of Kir2.1, and is not lethal to honey bees. Medicinal chemistry was used to develop an analog, termed VU730, which retains activity toward mosquito Kir1 but is not active against Kir2.1 or other mammalian Kir channels. Thus, VU041 and VU730 are promising chemical scaffolds for developing new classes of insecticides to combat insecticide-resistant mosquitoes and the transmission of mosquito-borne diseases, such as Zika virus, without harmful effects on humans and beneficial insects.
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Affiliation(s)
- Daniel R Swale
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN 37232, USA.,Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, LA, 70803, USA
| | - Darren W Engers
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Sean R Bollinger
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Aaron Gross
- Department of Entomology and Nematology, University of Florida, Gainesville, FL 32610, USA
| | - Edna Alfaro Inocente
- Department of Entomology, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH 44691, USA
| | - Emily Days
- Vanderbilt Institute of Chemical Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Fariba Kanga
- Department of Entomology, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH 44691, USA
| | - Reed M Johnson
- Department of Entomology, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH 44691, USA
| | - Liu Yang
- Department of Entomology, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH 44691, USA
| | - Jeffrey R Bloomquist
- Department of Entomology and Nematology, University of Florida, Gainesville, FL 32610, USA
| | - Corey R Hopkins
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN 37232, USA.,Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA
| | - Peter M Piermarini
- Department of Entomology, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH 44691, USA
| | - Jerod S Denton
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN 37232, USA.,Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.,Vanderbilt Institute of Chemical Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA.,Institute for Global Health, Vanderbilt University, Nashville, TN 37203, USA
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63
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Frederick J, Saint Jean Y, Lemoine JF, Dotson EM, Mace KE, Chang M, Slutsker L, Le Menach A, Beier JC, Eisele TP, Okech BA, Beau de Rochars VM, Carter KH, Keating J, Impoinvil DE. Malaria vector research and control in Haiti: a systematic review. Malar J 2016; 15:376. [PMID: 27443992 PMCID: PMC4957415 DOI: 10.1186/s12936-016-1436-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 07/10/2016] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND Haiti has a set a target of eliminating malaria by 2020. However, information on malaria vector research in Haiti is not well known. This paper presents results from a systematic review of the literature on malaria vector research, bionomics and control in Haiti. METHODS A systematic search of literature published in French, Spanish and English languages was conducted in 2015 using Pubmed (MEDLINE), Google Scholar, EMBASE, JSTOR WHOLIS and Web of Science databases as well other grey literature sources such as USAID, and PAHO. The following search terms were used: malaria, Haiti, Anopheles, and vector control. RESULTS A total of 132 references were identified with 40 high quality references deemed relevant and included in this review. Six references dealt with mosquito distribution, seven with larval mosquito ecology, 16 with adult mosquito ecology, three with entomological indicators of malaria transmission, eight with insecticide resistance, one with sero-epidemiology and 16 with vector control. In the last 15 years (2000-2015), there have only been four published papers and three-scientific meeting abstracts on entomology for malaria in Haiti. Overall, the general literature on malaria vector research in Haiti is limited and dated. DISCUSSION Entomological information generated from past studies in Haiti will contribute to the development of strategies to achieve malaria elimination on Hispaniola. However it is of paramount importance that malaria vector research in Haiti is updated to inform decision-making for vector control strategies in support of malaria elimination.
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Affiliation(s)
- Joseph Frederick
- />Programme National de Contrôle de la Malaria, Port-au-Prince, Haiti
| | - Yvan Saint Jean
- />Programme National de Contrôle de la Malaria, Port-au-Prince, Haiti
| | | | - Ellen M. Dotson
- />Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA USA
| | - Kimberly E. Mace
- />Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA USA
| | - Michelle Chang
- />Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA USA
| | - Laurence Slutsker
- />Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA USA
| | | | - John C. Beier
- />Division of Environment & Public Health, Department of Public Health Sciences, University of Miami Miller School of Medicine, Miami, FL USA
| | - Thomas P. Eisele
- />Center for Applied Malaria Research and Evaluation, Department of Tropical Medicine, Tulane School of Public Health and Tropical Medicine, New Orleans, LA USA
| | - Bernard A. Okech
- />Department of Environmental and Global Health College of Public Health and Health Professions, Emerging Pathogens Institute, Gainesville, FL USA
| | - Valery Madsen Beau de Rochars
- />Department of Health Service Research Management and Policy of College of Public Health and Health Professions, Emerging Pathogens Institute, Gainesville, FL USA
- />The Carter Center, Atlanta, GA USA
| | - Keith H. Carter
- />Department of Communicable Diseases and Health Analysis, Pan American Health Organization/World Health Organization, Washington, DC USA
| | - Joseph Keating
- />Center for Applied Malaria Research and Evaluation, Department of Tropical Medicine, Tulane School of Public Health and Tropical Medicine, New Orleans, LA USA
| | - Daniel E. Impoinvil
- />Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA USA
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Ōmura S. Ein vortreffliches Geschenk der Erde: Ursprünge und Auswirkungen der Avermectine (Nobel-Aufsatz). Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201602164] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Satoshi Ōmura
- Kitasato University; Kitasato Institute for Life Sciences; Minato-ku, 9-1, Shirokane 5-chome Tokyo 108-8642 Japan
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Ōmura S. A Splendid Gift from the Earth: The Origins and Impact of the Avermectins (Nobel Lecture). Angew Chem Int Ed Engl 2016; 55:10190-209. [PMID: 27435664 DOI: 10.1002/anie.201602164] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Indexed: 11/08/2022]
Abstract
Japanese soil was the origin of one of the most important drugs of the world: ivermectin. No other drug has such importance for the health of millions of people, particularly in the poor regions of the world. The discovery of the parent compounds of the avermectines is described first hand by S. Ōmura.
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Affiliation(s)
- Satoshi Ōmura
- Kitasato University, Kitasato Institute for Life Sciences, Minato-ku, 9-1, Shirokane 5-chome, Tokyo, 108-8642, Japan.
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66
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Toxicity and potential utility of ivermectin and moxidectin as xenointoxicants against the common bed bug, Cimex lectularius L. Parasitol Res 2016; 115:3071-81. [DOI: 10.1007/s00436-016-5062-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 04/08/2016] [Indexed: 12/30/2022]
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Stuckey EM, Miller JM, Littrell M, Chitnis N, Steketee R. Operational strategies of anti-malarial drug campaigns for malaria elimination in Zambia's southern province: a simulation study. Malar J 2016; 15:148. [PMID: 26957364 PMCID: PMC4784285 DOI: 10.1186/s12936-016-1202-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Accepted: 03/01/2016] [Indexed: 01/28/2023] Open
Abstract
Background Malaria elimination requires reducing both the potential of mosquitoes to transmit parasites to humans and humans to transmit parasites to mosquitoes. To achieve this goal in Southern province, Zambia a mass test and treat (MTAT) campaign was conducted from 2011–2013 to complement high coverage of long-lasting insecticide-treated nets (LLIN). To identify factors likely to increase campaign effectiveness, a modelling approach was applied to investigate the simulated effect of alternative operational strategies for parasite clearance in southern province. Methods OpenMalaria, a discrete-time, individual-based stochastic model of malaria, was parameterized for the study area to simulate anti-malarial drug administration for interruption of transmission. Simulations were run for scenarios with a range of artemisinin-combination therapies, proportion of the population reached by the campaign, targeted age groups, time between campaign rounds, Plasmodium falciparum test protocols, and the addition of drugs aimed at preventing onward transmission. A sensitivity analysis was conducted to assess uncertainty of simulation results. Scenarios were evaluated based on the reduction in all-age parasite prevalence during the peak transmission month one year following the campaign, compared to the currently-implemented strategy of MTAT 19 % population coverage at pilot and 40 % coverage during the first year of implementation in the presence of 56 % LLIN use and 18 % indoor residual spray coverage. Results Simulation results suggest the most important determinant of success in reducing prevalence is the population coverage achieved in the campaign, which would require more than 1 year of campaign implementation for elimination. The inclusion of single low-dose primaquine, which acts as a gametocytocide, or ivermectin, which acts as an endectocide, to the drug regimen did not further reduce parasite prevalence one year following the campaign compared to the currently-implemented strategy. Simulation results indicate a high proportion of low-density infections were missed by rapid diagnostic tests that would be treated and cleared with mass drug administration (MDA). Conclusions The optimal implementation strategy for MTAT or MDA will vary by background level of prevalence, by rate of infections imported to the area, and by ability to operationally achieve high population coverage. Overall success with new parasite clearance strategies depends on continued coverage of vector control interventions to ensure sustained gains in reduction of disease burden.
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Affiliation(s)
- Erin M Stuckey
- Swiss Tropical and Public Health Institute, Basel, Switzerland. .,University of Basel, Basel, Switzerland. .,Bill & Melinda Gates Foundation, Seattle, WA, USA.
| | | | | | - Nakul Chitnis
- Swiss Tropical and Public Health Institute, Basel, Switzerland. .,University of Basel, Basel, Switzerland.
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68
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Derua YA, Malongo BB, Simonsen PE. Effect of ivermectin on the larvae of Anopheles gambiae and Culex quinquefasciatus. Parasit Vectors 2016; 9:131. [PMID: 26951712 PMCID: PMC4782284 DOI: 10.1186/s13071-016-1417-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 03/01/2016] [Indexed: 11/25/2022] Open
Abstract
Background Ivermectin is used extensively globally for treatment of helminthic and ectoparasitic infections in animals and humans. The effect of excreted ivermectin on non-target organisms in aquatic and terrestrial environments has been increasingly reported. Due to its low water solubility and adsorption to sediments, the ivermectin exposure-risk to aquatic organisms dwelling in different strata of water bodies varies. This study assessed the survival of larvae of Anopheles gambiae Giles and Culex quinquefasciatus Say, when exposed to low concentrations of ivermectin under laboratory conditions. Methods A total of 1800 laboratory reared mosquito larvae of each species were used in the bioassays. Twelve replicates were performed, each testing 6 concentrations of ivermectin (0.0, 0.001, 0.01, 0.1, 1.0 and 10.0 parts per million (ppm)) against third instar larvae of An. gambiae and Cx. quinquefasciatus. Larval mortality was recorded at 24 and 48 h post addition of ivermectin. Results Survival declined markedly with increase in ivermectin concentration in both species. While mean survival of An. gambiae at 24 h of exposure was 99.6 %, 99.2 % and 61.6 % in 0.001, 0.01 and 0.1 ppm of ivermectin, respectively, the mean survival of Cx. quinquefasciatus at the same dosage and time was 89.2 %, 47.2 % and 0.0 %. A similar pattern, but with higher mortality, was observed after 48 h of exposure. Comparison between the species revealed that Cx. quinquefasciatus larvae were significantly more affected by ivermectin than those of An. gambiae, both at 24 and 48 h. Conclusions Low concentrations of ivermectin in the aquatic environment reduced the survival of larvae of An. gambiae and Cx. quinquefasciatus, with the effect being more marked in the latter species. It is suggested that this difference may be due to the different water strata occupied by the two species, with ivermectin adsorbed in food that sediment being more readily available to the bottom feeding Cx. quinquefasciatus than the surface feeding An. gambiae larvae.
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Affiliation(s)
- Yahya A Derua
- National Institute for Medical Research, Amani Research Centre, P. O. Box 81, Muheza, Tanga, Tanzania.
| | - Bernard B Malongo
- National Institute for Medical Research, Amani Research Centre, P. O. Box 81, Muheza, Tanga, Tanzania.
| | - Paul E Simonsen
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Dyrlægevej 100, 1870 Frederiksberg C, Copenhagen, Denmark.
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69
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Yakob L. Endectocide-treated cattle for malaria control: A coupled entomological-epidemiological model. Parasite Epidemiol Control 2016. [PMCID: PMC5991820 DOI: 10.1016/j.parepi.2015.12.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The malaria vector landscape is dynamic and dependence on indoor control tools has drastically affected both species compositions and local mosquito biting behaviours. In the advent of spreading behavioural resilience and physiological resistance to insecticidal nets and house spray, approaches to target more zoophilic, outdoor-biting vectors are being sought with increased urgency. Endectocides are insecticides applied to hosts which are taken up by the vectors during biting, and recent field assessments have demonstrated favourable results of cattle treated with ivermectin, diflubenzuron, eprinomectin and fipronil. Models were constructed to account for the modern, diverse vector feeding behaviours and assess their role in shaping malaria transmission and control with cattle-treated endectocides. Efficacy of this novel approach to malaria control is shown to be strongly dependent not only on intrinsic host preferences of the vector but also on how this preference is augmented by variation in the encounter rates with alternative blood-hosts. Ecological scenarios are presented whereby endectocides used on cattle yield equivalent, and in some cases improved, efficacy over nets and spray in controlling malaria transmission. Interactions between mosquito biting behaviours and relative availabilities of alternative blood-host species have largely been neglected in malaria programmatic strategy but will increasingly underlie sustaining the successes of vector control initiatives.
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70
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Pooda HS, Rayaisse JB, Hien DFDS, Lefèvre T, Yerbanga SR, Bengaly Z, Dabiré RK, Belem AMG, Sidibé I, Solano P, Mouline K. Administration of ivermectin to peridomestic cattle: a promising approach to target the residual transmission of human malaria. Malar J 2015; 13 Suppl 1:496. [PMID: 26651335 PMCID: PMC4676103 DOI: 10.1186/s12936-015-1001-z] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2015] [Accepted: 11/19/2015] [Indexed: 11/27/2022] Open
Abstract
Background The success of current control tools in combatting malaria vectors is well established. However, sustained residual transmission of Plasmodium parasites persists. Mass drug administration (MDA) to humans of the endectocide ivermectin for vector control is receiving increasing attention. However, vectors feeding upon animals escape this promising approach. Zoophagy of mosquitoes sustains both the vector population and endemic population of vector-borne pathogens. Therefore, only a strategy that will combine ivermectin MDAs targeted at humans and their peridomestic animals could be successful at controlling residual malaria transmission. Methods Burkinabé cattle have been treated with injectable therapeutic dose of ivermectin (0.2 mg/kg of body weight) to render blood meals toxic to field representative populations of Anopheles coluzzii carrying the kdr mutation. Direct skin-feeding assays were performed from 2 to 28 days after injection (DAI) and mosquitoes were followed for their survival, ability to become gravid and fecundity. Membrane feeding assays were further performed to test if an ivermectin blood meal taken at 28 DAI impacts gametocyte establishment and development in females fed with infectious blood. Results The mosquitocidal effect of ivermectin is complete for 2 weeks after injection, whether 12 days cumulative mortalities were of 75 and 45 % the third and fourth weeks, respectively. The third week, a second ivermectin blood meal at sub-lethal concentrations further increased mortality to 100 %. Sub-lethal concentrations of ivermectin also significantly decreased egg production by surviving females, increasing further the detrimental effect of the drug on vector densities. Although females fitness was impaired by sub-lethal ivermectin blood meals, these did not diminish nor increase their susceptibility to infection. Conclusion This study demonstrates the potential of integrated MDA of ivermectin to both human and peridomestic cattle to target vector reservoirs of residual malaria transmission. Such integration lies in ‘One-Health’ efforts being implemented around the globe, and would be especially relevant in rural communities in Africa where humans are also at risk of common zoonotic diseases. Electronic supplementary material The online version of this article (doi:10.1186/s12936-015-1001-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hermann S Pooda
- Centre International de Recherche-Développement sur l'Elevage en Zone Subhumide, Bobo-Dioulasso, Burkina Faso. .,Ministère des Ressources Animale/Campagne Panafricaine d'éradication de la mouche tsé-tsé et des trynaposomoses, Bobo-Dioulasso, Burkina Faso. .,Université Polytechnique de Bobo-Dioulasso, Bobo-Dioulasso, Burkina Faso.
| | - Jean-Baptiste Rayaisse
- Centre International de Recherche-Développement sur l'Elevage en Zone Subhumide, Bobo-Dioulasso, Burkina Faso.
| | | | - Thierry Lefèvre
- Direction Régionale de l'Ouest de l'Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso. .,MIVEGEC (Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle), UMR IRD 224, CNRS 5290, Université de Montpellier, 911 Av. Agropolis, Montpellier, France.
| | - Serge R Yerbanga
- Direction Régionale de l'Ouest de l'Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso.
| | - Zakaria Bengaly
- Centre International de Recherche-Développement sur l'Elevage en Zone Subhumide, Bobo-Dioulasso, Burkina Faso.
| | - Roch K Dabiré
- Direction Régionale de l'Ouest de l'Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso.
| | - Adrien M G Belem
- Université Polytechnique de Bobo-Dioulasso, Bobo-Dioulasso, Burkina Faso.
| | - Issa Sidibé
- Centre International de Recherche-Développement sur l'Elevage en Zone Subhumide, Bobo-Dioulasso, Burkina Faso. .,Ministère des Ressources Animale/Campagne Panafricaine d'éradication de la mouche tsé-tsé et des trynaposomoses, Bobo-Dioulasso, Burkina Faso.
| | - Philippe Solano
- UMR INTERTRYP IRD-CIRAD, TA A 17/G, Campus International de Baillarguet, 34398, Montpellier cedex 5, France.
| | - Karine Mouline
- Direction Régionale de l'Ouest de l'Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso. .,MIVEGEC (Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle), UMR IRD 224, CNRS 5290, Université de Montpellier, 911 Av. Agropolis, Montpellier, France.
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Poché RM, Burruss D, Polyakova L, Poché DM, Garlapati RB. Treatment of livestock with systemic insecticides for control of Anopheles arabiensis in western Kenya. Malar J 2015; 14:351. [PMID: 26377691 PMCID: PMC4574316 DOI: 10.1186/s12936-015-0883-0] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 09/03/2015] [Indexed: 12/01/2022] Open
Abstract
Background Despite the implementation of vector control strategies, including insecticide-treated bed nets (ITN) and indoor residual spraying (IRS) in western Kenya, this area still experiences high level of malaria transmission. Novel vector control tools are required which target such vector species, such as Anopheles arabiensis, that feed outdoors and have minimal contact with ITNs and IRS. Methods To address this need, ivermectin, eprinomectin, and fipronil were evaluated in Zebu cattle under semi-field conditions to evaluate the potential of these compounds to reduce the survival of blood feeding An. arabiensis. Over the course of four experiments, lactating cattle received doses of oral ivermectin at 0.1 or 0.2 mg/kg, oral eprinomectin at 0.2 or 0.5 mg/kg, topical eprinomectin at 0.5, 0.75, or 1.5 mg/kg, or oral fipronil at 0.25, 0.5, 1.0, or 1.5 mg/kg. On days 1, 3, 5, 7, 14, and 21 days post-treatment, cattle were exposed to An. arabiensis, and mosquito mortality post-blood feeding was monitored. For the analysis of survival data, the Kaplan–Meier estimator and Mantel–Haenszel test was used to contrast the treatment and control survival functions. Results All three compounds significantly reduced the survival time of An. arabiensis. Twenty-one days post-treatment, mortality of mosquitoes fed on cattle dosed orally with 0.2 or 0.5 mg/kg eprinomectin, topically with eprinomectin at 0.5 mg/kg, or orally with either 1.0 or 1.5 mg/kg fipronil was still significantly higher than control mortality. Conclusions These data demonstrate the effectiveness of three insecticidal compounds administered systemically to cattle for controlling the cattle-feeding mosquito An. arabiensis. Eprinomectin and fipronil provided the longest-lasting control. Such endectocidal treatments in cattle are a promising new strategy for control of residual, outdoor malaria transmission and could effectively augment current interventions which target more endophilic vector species. Electronic supplementary material The online version of this article (doi:10.1186/s12936-015-0883-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Richard M Poché
- Genesis Laboratories, P.O. Box 1195, Wellington, CO, 80549, USA.
| | - Dylan Burruss
- Genesis Laboratories, P.O. Box 1195, Wellington, CO, 80549, USA.
| | - Larisa Polyakova
- Genesis Laboratories, P.O. Box 1195, Wellington, CO, 80549, USA.
| | - David M Poché
- Genesis Laboratories, P.O. Box 1195, Wellington, CO, 80549, USA.
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Chaccour C, Barrio ÁI, Royo AGG, Urbistondo DM, Slater H, Hammann F, Del Pozo JL. Screening for an ivermectin slow-release formulation suitable for malaria vector control. Malar J 2015; 14:102. [PMID: 25872986 PMCID: PMC4355127 DOI: 10.1186/s12936-015-0618-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 02/20/2015] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND The prospect of eliminating malaria is challenged by emerging insecticide resistance and vectors with outdoor and/or crepuscular activity. Ivermectin can simultaneously tackle these issues by killing mosquitoes feeding on treated animals and humans. A single oral dose, however, confers only short-lived mosquitocidal plasma levels. METHODS Three different slow-release formulations of ivermectin were screened for their capacity to sustain mosquito-killing levels of ivermectin for months. Thirty rabbits received a dose of one, two or three silicone implants containing different proportions of ivermectin, deoxycholate and sucrose. Animals were checked for toxicity and ivermectin was quantified periodically in blood. Potential impact of corresponding long-lasting formulation was mathematically modelled. RESULTS All combinations of formulation and dose released ivermectin for more than 12 weeks; four combinations sustained plasma levels capable of killing 50% of Anopheles gambiae feeding on a treated subject for up to 24 weeks. No major adverse effects attributable to the drug were found. Modelling predicts a 98% reduction in infectious vector density by using an ivermectin formulation with a 12-week duration. CONCLUSIONS These results indicate that relatively stable mosquitocidal plasma levels of ivermectin can be safely sustained in rabbits for up to six months using a silicone-based subcutaneous formulation. Modifying the formulation of ivermectin promises to be a suitable strategy for malaria vector control.
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Affiliation(s)
- Carlos Chaccour
- />Department of Internal Medicine, Clinica Universidad de Navarra, Pio XII 36, Pamplona, 31008 Spain
- />Barcelona Institute for Global Health (ISGlobal), Barcelona, Spain
- />Instituto de Salud Tropical, Universidad de Navarra, Pamplona, Spain
| | - Ángel Irigoyen Barrio
- />Faculty of Pharmacy, Universidad de Navarra, Pamplona, 31008 Spain
- />Drug Development Unit Universidad de Navarra (DDUNAV), Pamplona, Spain
| | - Ana Gloria Gil Royo
- />Faculty of Pharmacy, Universidad de Navarra, Pamplona, 31008 Spain
- />Drug Development Unit Universidad de Navarra (DDUNAV), Pamplona, Spain
| | - Diego Martinez Urbistondo
- />Department of Internal Medicine, Clinica Universidad de Navarra, Pio XII 36, Pamplona, 31008 Spain
| | - Hannah Slater
- />Department of Infectious Disease Epidemiology, MRC Centre for Outbreak Analysis and Modelling, Imperial College London, London, UK
| | - Felix Hammann
- />Cantonal Hospital Baselland, Medical University Clinic, Liestal, Switzerland
| | - Jose Luis Del Pozo
- />Instituto de Salud Tropical, Universidad de Navarra, Pamplona, Spain
- />Infectious Disease Unit, Clinica Universidad de Navarra, Pamplona, Spain
- />Department of Microbiology, Clinica Universidad de Navarra, Pamplona, Spain
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Differential effect of human ivermectin treatment on blood feeding Anopheles gambiae and Culex quinquefasciatus. Parasit Vectors 2015; 8:130. [PMID: 25885477 PMCID: PMC4352294 DOI: 10.1186/s13071-015-0735-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 02/13/2015] [Indexed: 12/03/2022] Open
Abstract
Background Widespread and large scale use of ivermectin in humans and domestic animals can have unexpected effects on non-target organisms. As a search for a possible explanation for an observed longitudinal decline in density of anopheline vector mosquitoes, but not in Culex quinquefasciatus, in an area of north-eastern Tanzania which has been exposed to ivermectin mass drug administration, this study assessed and compared the effect of human ivermectin treatment on blood feeding Anopheles gambiae and Cx. quinquefasciatus. Methods Consenting adult volunteers were randomized into two groups to receive either ivermectin or placebo. Twenty four hours after treatment, one volunteer from each group was concurrently exposed to 50 laboratory reared An. gambiae on one arm and 50 laboratory reared Cx. quinquefasciatus on the other arm for 15–30 minutes. Engorged mosquitoes were maintained on 10% glucose solution for 12 days and observed for survival and fecundity. The experiment was repeated 15 times. Results Two days after the blood meals, nearly half (average 47.7% for the 15 experiments) of the blood fed An. gambiae in the ivermectin group had died while almost all in the placebo group were alive (97.2%), and the difference in survival between these two groups continued to widen on the following days. There was no clear effect of ivermectin on Cx. quinquefasciatus, which had high survival in both ivermectin and placebo group on day 2 (95.7% and 98.4%, respectively) as well as on the following days. Ivermectin completely inhibited egg laying in An. gambiae, while egg laying and subsequent development of immature stages appeared normal in the other three groups. Conclusion Blood meals taken on ivermectin treated volunteers significantly reduced survival and halted fecundity of An. gambiae but had only limited or no effect on Cx. quinquefasciatus. The result suggests that widespread use of ivermectin may have contributed to the observed decline in density of An. gambiae, without similar decrease in Cx. quinquefasciatus, in north-eastern Tanzania.
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Steketee RW, Ter Kuile FO. Ivermectin as a complementary strategy to kill mosquitoes and stop malaria transmission? Clin Infect Dis 2014; 60:366-8. [PMID: 25414261 DOI: 10.1093/cid/ciu802] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Alout H, Krajacich BJ, Meyers JI, Grubaugh ND, Brackney DE, Kobylinski KC, Diclaro JW, Bolay FK, Fakoli LS, Diabaté A, Dabiré RK, Bougma RW, Foy BD. Evaluation of ivermectin mass drug administration for malaria transmission control across different West African environments. Malar J 2014; 13:417. [PMID: 25363349 PMCID: PMC4226880 DOI: 10.1186/1475-2875-13-417] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2014] [Accepted: 10/25/2014] [Indexed: 11/06/2022] Open
Abstract
Background Mass drug administration (MDA) of ivermectin to humans for control and elimination of filarial parasites can kill biting malaria vectors and lead to Plasmodium transmission reduction. This study examines the degree and duration of mosquitocidal effects resulting from single MDAs conducted in three different West African countries, and the subsequent reductions in parity and Plasmodium sporozoite rates. Methods Indoor-resting, blood-fed and outdoor host-seeking Anopheles spp. were captured on days surrounding MDAs from 2008–2013 in Senegalese, Liberian and Burkinabé villages. Mortality was assessed on a portion of the indoor collection, and parity status was determined on host-seeking mosquitoes. The effect of MDA was then analysed against the time relative to the MDA, the distributed drugs and environmental variables. Results Anopheles gambiae survivorship was reduced by 33.9% for one week following MDA and parity rates were significantly reduced for more than two weeks after the MDAs. Sporozoite rates were significantly reduced by >77% for two weeks following the MDAs in treatment villages despite occurring in the middle of intense transmission seasons. These observed effects were consistent across three different West African transmission dynamics. Conclusions These data provide a comprehensive and crucial evidence base for the significant reduction in malaria transmission following single ivermectin MDAs across diverse field sites. Despite the limited duration of transmission reduction, these results support the hypothesis that repeated MDAs with optimal timing could help sustainably control malaria as well as filarial transmission. Electronic supplementary material The online version of this article (doi:10.1186/1475-2875-13-417) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Haoues Alout
- Arthropod-borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, USA.
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Kobylinski KC, Alout H, Foy BD, Clements A, Adisakwattana P, Swierczewski BE, Richardson JH. Rationale for the coadministration of albendazole and ivermectin to humans for malaria parasite transmission control. Am J Trop Med Hyg 2014; 91:655-62. [PMID: 25070998 PMCID: PMC4183382 DOI: 10.4269/ajtmh.14-0187] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 06/04/2014] [Indexed: 10/25/2022] Open
Abstract
Recently there have been calls for the eradication of malaria and the elimination of soil-transmitted helminths (STHs). Malaria and STHs overlap in distribution, and STH infections are associated with increased risk for malaria. Indeed, there is evidence that suggests that STH infection may facilitate malaria transmission. Malaria and STH coinfection may exacerbate anemia, especially in pregnant women, leading to worsened child development and more adverse pregnancy outcomes than these diseases would cause on their own. Ivermectin mass drug administration (MDA) to humans for malaria parasite transmission suppression is being investigated as a potential malaria elimination tool. Adding albendazole to ivermectin MDAs would maximize effects against STHs. A proactive, integrated control platform that targets malaria and STHs would be extremely cost-effective and simultaneously reduce human suffering caused by multiple diseases. This paper outlines the benefits of adding albendazole to ivermectin MDAs for malaria parasite transmission suppression.
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Affiliation(s)
- Kevin C Kobylinski
- Entomology Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland; Arthropod-Borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado; Research School of Population Health, The Australian National University, Canberra, Australian Capitol Territory, Australia; Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland; Deployed Warfighter Protection Program, Armed Forces Pest Management Board, Silver Spring, Maryland
| | - Haoues Alout
- Entomology Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland; Arthropod-Borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado; Research School of Population Health, The Australian National University, Canberra, Australian Capitol Territory, Australia; Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland; Deployed Warfighter Protection Program, Armed Forces Pest Management Board, Silver Spring, Maryland
| | - Brian D Foy
- Entomology Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland; Arthropod-Borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado; Research School of Population Health, The Australian National University, Canberra, Australian Capitol Territory, Australia; Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland; Deployed Warfighter Protection Program, Armed Forces Pest Management Board, Silver Spring, Maryland
| | - Archie Clements
- Entomology Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland; Arthropod-Borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado; Research School of Population Health, The Australian National University, Canberra, Australian Capitol Territory, Australia; Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland; Deployed Warfighter Protection Program, Armed Forces Pest Management Board, Silver Spring, Maryland
| | - Poom Adisakwattana
- Entomology Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland; Arthropod-Borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado; Research School of Population Health, The Australian National University, Canberra, Australian Capitol Territory, Australia; Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland; Deployed Warfighter Protection Program, Armed Forces Pest Management Board, Silver Spring, Maryland
| | - Brett E Swierczewski
- Entomology Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland; Arthropod-Borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado; Research School of Population Health, The Australian National University, Canberra, Australian Capitol Territory, Australia; Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland; Deployed Warfighter Protection Program, Armed Forces Pest Management Board, Silver Spring, Maryland
| | - Jason H Richardson
- Entomology Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland; Arthropod-Borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado; Research School of Population Health, The Australian National University, Canberra, Australian Capitol Territory, Australia; Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland; Deployed Warfighter Protection Program, Armed Forces Pest Management Board, Silver Spring, Maryland
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77
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Omura S, Crump A. Ivermectin: panacea for resource-poor communities? Trends Parasitol 2014; 30:445-55. [PMID: 25130507 DOI: 10.1016/j.pt.2014.07.005] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2014] [Revised: 07/12/2014] [Accepted: 07/15/2014] [Indexed: 02/03/2023]
Abstract
The 2014 Gairdner Global Health Award was conferred for discovery of the unique microorganism that is the sole source of the endectocidal avermectins, and the Public sector/Private sector Partnership that developed innovative biopharmaceuticals with immeasurably beneficial impact on public health worldwide. Ivermectin is already labelled a 'wonder drug', essential for campaigns to eliminate two disfiguring and devastating tropical diseases. New uses for it are identified regularly, including possible antibacterial, antiviral, and anticancer potential. Hundreds of millions of people are taking ivermectin to combat various diseases and afflictions, and mass administration of ivermectin in polyparasitised poor communities around the world is increasingly recognised as a mechanism to easily and cost-effectively improve overall health and quality of life for everyone.
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Affiliation(s)
- Satoshi Omura
- The Kitasato Institute and Kitasato University, 5-9-1 Shirokane, Minato-Ku, Tokyo 108-8641, Japan
| | - Andy Crump
- The Kitasato Institute and Kitasato University, 5-9-1 Shirokane, Minato-Ku, Tokyo 108-8641, Japan.
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Dantas-Torres F, Cameron MM, Colwell DD, Otranto D. A look into the Medical and Veterinary Entomology crystal ball. MEDICAL AND VETERINARY ENTOMOLOGY 2014; 28 Suppl 1:6-13. [PMID: 25171603 DOI: 10.1111/mve.12066] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Medical and Veterinary Entomology (MVE) represents a leading periodical in its field and covers many aspects of the biology and control of insects, ticks, mites and other arthropods of medical and veterinary importance. Since the first issue of the journal, researchers working in both developed and developing countries have published in MVE, with direct impact on current knowledge in the field. An increasing number of articles dealing with the epidemiology and transmission of vector-borne pathogens have been published in MVE, reflecting rapid changes in vector distribution, pathogen transmission and host-arthropod interactions. This article represents a gaze into the crystal ball in which we identify areas of increasing interest, discuss the main changes that have occurred in the epidemiology of parasitic arthropods since the first issue of MVE, and predict the principal scientific topics that might arise in the next 25 years for scientists working in medical and veterinary entomology.
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Affiliation(s)
- F Dantas-Torres
- Department of Immunology, Aggeu Magalhães Research Centre, Oswaldo Cruz Foundation, Recife, PE, Brazil; Department of Veterinary Medicine, University of Bari, Valenzano, Bari, Italy
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Sylla M, Kobylinski KC, Foy BD. Endectocides for controlling transmission of mosquito-borne diseases. MALARIAWORLD JOURNAL 2013; 4:5. [PMID: 24818085 PMCID: PMC4013271 DOI: 10.5281/zenodo.10894657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Grants] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 06/05/2024]
Affiliation(s)
- Massamba Sylla
- Arthropod-borne Infectious Disease Laboratory, Department of Microbiology, Immunology and Pathology, Colorado State University, 1692 Campus Delivery, Fort Collins, CO, USA 80523-1692
| | - Kevin C. Kobylinski
- Entomology Branch, Walter Reed Army Institute of Research, 503 Robert Grant Ave, Silver Spring, MD, USA, 20910
| | - Brian D. Foy
- Arthropod-borne Infectious Disease Laboratory, Department of Microbiology, Immunology and Pathology, Colorado State University, 1692 Campus Delivery, Fort Collins, CO, USA 80523-1692
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80
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Chaccour CJ, Kobylinski KC, Bassat Q, Bousema T, Drakeley C, Alonso P, Foy BD. Ivermectin to reduce malaria transmission: a research agenda for a promising new tool for elimination. Malar J 2013; 12:153. [PMID: 23647969 PMCID: PMC3658945 DOI: 10.1186/1475-2875-12-153] [Citation(s) in RCA: 121] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Accepted: 05/01/2013] [Indexed: 11/11/2022] Open
Abstract
Background The heterogeneity of malaria transmission makes widespread elimination a difficult goal to achieve. Most of the current vector control measures insufficiently target outdoor transmission. Also, insecticide resistance threatens to diminish the efficacy of the most prevalent measures, indoor residual spray and insecticide treated nets. Innovative approaches are needed. The use of endectocides, such as ivermectin, could be an important new addition to the toolbox of anti-malarial measures. Ivermectin effectively targets outdoor transmission, has a novel mechanism of action that could circumvent resistance and might be distributed over the channels already in place for the control of onchocerciasis and lymphatic filariasis. Methods The previous works involving ivermectin and Anopheles vectors are reviewed and summarized. A review of ivermectin’s safety profile is also provided. Finally three definitive clinical trials are described in detail and proposed as the evidence needed for implementation. Several smaller and specific supportive studies are also proposed. Conclusions The use of ivermectin solves many challenges identified for future vector control strategies. It is an effective and safe endectocide that was approved for human use more than 25 years ago. Recent studies suggest it might become an effective and complementary strategy in malaria elimination and eradication efforts; however, intensive research will be needed to make this a reality.
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Affiliation(s)
- Carlos J Chaccour
- Internal Medicine Department, Clínica Universidad de Navarra, Av, Pio XII 36, Pamplona 31008, Spain.
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81
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Kobylinski KC, Foy BD, Richardson JH. Ivermectin inhibits the sporogony of Plasmodium falciparum in Anopheles gambiae. Malar J 2012; 11:381. [PMID: 23171202 PMCID: PMC3519548 DOI: 10.1186/1475-2875-11-381] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Accepted: 11/17/2012] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND When ingested in a blood meal, ivermectin has been shown to reduce the survivorship of Anopheles gambiae in the laboratory and field. Furthermore, ivermectin mass drug administrations in Senegal have been shown to reduce the proportion of Plasmodium falciparum-sporozoite-containing An. gambiae. This study addresses whether ivermectin inhibits sporogony of P. falciparum in An. gambiae. METHODS Anophele gambiae s.s. G3 strain were fed two concentrations of ivermectin (LC25 and LC5) along with P. falciparum NF54 in human blood meals at staggered intervals. Mosquitoes ingested ivermectin concurrent with parasites (DPI 0), or at three (DPI 3), six (DPI 6), and nine (DPI 9) days post parasite ingestion, or three days prior (DPI -3) to parasite ingestion. Mosquitoes were dissected at seven, twelve or fourteen days post parasite ingestion and either oocyst or sporozoite prevalence was recorded. To determine if P. falciparum sporozoite-containing An. gambiae were more susceptible to ivermectin than uninfected controls, survivorship was recorded for mosquitoes which ingested P. falciparum or control blood meal on DPI 0 and then a second blood meal containing ivermectin (LC25) on DPI 14. RESULTS Ivermectin (LC25) co-ingested (DPI 0) with parasites reduced the proportion of An. gambiae that developed oocysts (χ2 = 15.4842, P = 0.0002) and sporozoites (χ2 = 19.9643, P < 0.0001). Ivermectin (LC25) ingested DPI 6 (χ2 = 8.5103, P = 0.0044) and 9 (χ2 = 14.7998, P < 0.0001) reduced the proportion of An. gambiae that developed sporozoites but not when ingested DPI 3 (χ2 = 0.0113, P = 1). Ivermectin (LC5) co-ingested (DPI 0) with parasites did not reduce the proportion of An. gambiae that developed oocysts (χ2 = 4.2518, P = 0.0577) or sporozoites (χ2 = 2.3636, P = 0.1540), however, when ingested DPI -3 the proportion of An. gambiae that developed sporozoites was reduced (χ2 = 8.4806, P = 0.0047). Plasmodium falciparum infection significantly reduced the survivorship of An. gambiae that ingested ivermectin (LC25) on DPI 14 compared to control mosquitoes that ingested a primary blood meal without parasites (χ2 = 4.97, P = 0.0257). CONCLUSIONS Ivermectin at sub-lethal concentrations inhibits the sporogony of P. falciparum in An. gambiae. These findings support the utility of ivermectin for P. falciparum transmission control.
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Affiliation(s)
- Kevin C Kobylinski
- Entomology Branch, Walter Reed Army Institute of Research, 503 Robert Grant Ave, Silver Spring, MD, 20910, USA
| | - Brian D Foy
- Department of Microbiology, Immunology and Pathology, Arthropod-borne and Infectious Diseases Laboratory, Colorado State University, 1692 Campus Delivery, Fort Collins, CO, 80523-1692, USA
| | - Jason H Richardson
- Entomology Branch, Walter Reed Army Institute of Research, 503 Robert Grant Ave, Silver Spring, MD, 20910, USA
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Bastiaens GJH, vanGemert GJ, Hooghof J, Lindsay SW, Drakeley C, Churcher TS, Verhave JP, Kocken CHM, Sauerwein RW, Bousema T. Duration of the mosquitocidal effect of ivermectin. MALARIAWORLD JOURNAL 2012; 3:10. [PMID: 38854885 PMCID: PMC11153346 DOI: 10.5281/zenodo.10997577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Background Ivermectin (IVM) reduces the lifespan of malaria-transmitting mosquitoes after feeding on humans treated with IVM. If this effect is sufficiently long and strong, IVM could form part of a drug combination that not only treats malaria patients but also reduces onward transmission. Limited data are available on the exact duration of the mosquitocidal effect of IVM; daily mosquito feeding assays are required for this. Materials and Methods We determined mortality rates of Anopheles stephensi mosquitoes that took a blood meal on Swiss mice, Wistar rats and Cynomolgus monkeys that received IVM orally at 200-400 μg/kg. Mosquito feeding assays were performed on five consecutive days after IVM administration. Mosquito mortality was determined in the first 72 hours after feeding. Results Mosquito mortality was 70-100% when mosquitoes fed on any of the animals 1-2 days after the last IVM administration. After this time-point the mosquitocidal effect was still evident in some animals but became more variable. Conclusions Our findings of a pronounced but short-lived mosquitocidal effect makes the timing of IVM administration crucial to form a useful addition to anti-malarial drugs.
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Affiliation(s)
- Guido J H Bastiaens
- Radboud University Nijmegen Medical Centre, Department of Medical Microbiology, Nijmegen, The Netherlands
| | - Geert-Jan vanGemert
- Radboud University Nijmegen Medical Centre, Department of Medical Microbiology, Nijmegen, The Netherlands
| | - Jo Hooghof
- Radboud University Nijmegen Medical Centre, Department of Medical Microbiology, Nijmegen, The Netherlands
| | - Steve W Lindsay
- School of Biological and Biomedical Sciences, Science Laboratories, Durham University, UK
| | - Chris Drakeley
- Department of Immunology & Infection, London School of Hygiene and Tropical Medicine, United Kingdom
| | - Thomas S Churcher
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, UK
| | - Jan Peter Verhave
- Radboud University Nijmegen Medical Centre, Department of Medical Microbiology, Nijmegen, The Netherlands
| | - Clemens H M Kocken
- Department of Parasitology, Biomedical Primate Research Centre, Rijswijk, The Netherlands
| | - Robert W Sauerwein
- Radboud University Nijmegen Medical Centre, Department of Medical Microbiology, Nijmegen, The Netherlands
| | - Teun Bousema
- Radboud University Nijmegen Medical Centre, Department of Medical Microbiology, Nijmegen, The Netherlands
- Department of Immunology & Infection, London School of Hygiene and Tropical Medicine, United Kingdom
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van den Berg H, Kelly-Hope LA, Lindsay SW. Malaria and lymphatic filariasis: the case for integrated vector management. THE LANCET. INFECTIOUS DISEASES 2012; 13:89-94. [PMID: 23084831 DOI: 10.1016/s1473-3099(12)70148-2] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The global programmes to eliminate both malaria and lymphatic filariasis are facing operational and technical challenges. Available data show that the use of treated or untreated bednets and indoor residual spraying for malaria control concomitantly reduced filarial rates. In turn, mass drug administration campaigns against lymphatic filariasis can be combined with the distribution of insecticide-treated bednets. Combining these disease control efforts could lead to more efficient use of resources, more accurate attribution of effects, and more effective control of both diseases. Systematic integration requires coordination at all levels, mapping of coendemic areas, and comprehensive monitoring and evaluation.
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Affiliation(s)
- Henk van den Berg
- Laboratory of Entomology, Wageningen University, Wageningen, Netherlands.
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Deus KM, Saavedra-Rodriguez K, Butters MP, Black WC, Foy BD. The effect of ivermectin in seven strains of Aedes aegypti (Diptera: Culicidae) including a genetically diverse laboratory strain and three permethrin resistant strains. JOURNAL OF MEDICAL ENTOMOLOGY 2012; 49:356-63. [PMID: 22493855 PMCID: PMC3942497 DOI: 10.1603/me11164] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Seven different strains of Aedes aegypti (L.), including a genetically diverse laboratory strain, three laboratory-selected permethrin-resistant strains, a standard reference strain, and two recently colonized strains were fed on human blood containing various concentrations of ivermectin. Ivermectin reduced adult survival, fecundity, and hatch rate of eggs laid by ivermectin-treated adults in all seven strains. The LC50 of ivermectin for adults and the concentration that prevented 50% of eggs from hatching was calculated for all strains. Considerable variation in adult survival after an ivermectin-bloodmeal occurred among strains, and all three permethrin-resistant strains were significantly less susceptible to ivermectin than the standard reference strain. The hatch rate after an ivermectin bloodmeal was less variable among strains, and only one of the permethrin-resistant strains differed significantly from the standard reference strain. Our studies suggest that ivermectin induces adult mortality and decreases the hatch rate of eggs through different mechanisms. A correlation analysis of log-transformed LC50 among strains suggests that permethrin and ivermectin cross-resistance may occur.
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Affiliation(s)
- K M Deus
- Colorado State University, Department of Microbiology, Immunology and Pathology, 1692 Campus Delivery, Fort Collins, CO 80523, USA.
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Butters MP, Kobylinski KC, Deus KM, da Silva IM, Gray M, Sylla M, Foy BD. Comparative evaluation of systemic drugs for their effects against Anopheles gambiae. Acta Trop 2012; 121:34-43. [PMID: 22019935 DOI: 10.1016/j.actatropica.2011.10.007] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Revised: 10/06/2011] [Accepted: 10/07/2011] [Indexed: 12/11/2022]
Abstract
Laboratory and field studies have shown that ivermectin, a drug that targets invertebrate ligand-gated ion channels (LGICs), is potently active against Anopheles spp. mosquitoes at concentrations present in human blood after standard drug administrations; thus ivermectin holds promise as a mass human-administered endectocide that could help suppress malaria parasite transmission. We evaluated other systemic LGIC-targeting drugs for their activities against the African malaria vector Anopheles gambiae using in vitro blood feeding assays. Eprinomectin, selamectin, moxidectin, and N-tert-butyl nodulisporamide were evaluated as potentially systemic drugs having similar modes of action to ivermectin; all primarily are agonists of invertebrate glutamate-gated chloride ion channels. Additionally, nitenpyram and spinosad were evaluated as systemic drugs that primarily work as agonists of nicotinic acetylcholine receptor channels. Only eprinomectin killed An. gambiae at concentrations that were comparable to ivermectin. At sub-lethal doses, nitenpyram and moxidectin marginally affected mosquito re-blood feeding ability. The macrocyclic lactones, particularly eprinomectin, caused significantly increased knockdown and significantly inhibited recovery in blood fed females. These data are a first step in evaluating drugs that might be eventually combined with, or substituted for ivermectin for future malaria parasite transmission control.
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