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Ortega-López LD, Betancourth MP, León R, Kohl A, Ferguson HM. Behaviour and distribution of Aedes aegypti mosquitoes and their relation to dengue incidence in two transmission hotspots in coastal Ecuador. PLoS Negl Trop Dis 2024; 18:e0010932. [PMID: 38683840 PMCID: PMC11081501 DOI: 10.1371/journal.pntd.0010932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 05/09/2024] [Accepted: 02/08/2024] [Indexed: 05/02/2024] Open
Abstract
BACKGROUND Dengue (DENV) transmission is endemic throughout coastal Ecuador, showing heterogeneous incidence patterns in association with fine-scale variation in Aedes aegypti vector populations and other factors. Here, we investigated the impact of micro-climate and neighbourhood-level variation in urbanization on Aedes abundance, resting behaviour and associations with dengue incidence in two endemic areas. METHODOLOGY/PRINCIPAL FINDINGS Aedes aegypti were collected in Quinindé and Portoviejo, two urban cantons with hyperendemic dengue transmission in coastal Ecuador. Aedes vectors were sampled in and around houses within urban and peri-urban neighbourhoods at four time periods. We tested for variation in vector abundance and resting behaviour in relation to neighbourhood urbanization level and microclimatic factors. Aedes abundance increased towards the end of the rainy season, was significantly higher in Portoviejo than in Quinindé, and in urban than in peri-urban neighbourhoods. Aedes vectors were more likely to rest inside houses in Portoviejo but had similar abundance in indoor and outdoor resting collections in Quinindé. Over the study period, DENV incidence was lower in Quinindé than in Portoviejo. Relationships between weekly Ae. aegypti abundance and DENV incidence were highly variable between trapping methods; with positive associations being detected only between BG-sentinel and outdoor Prokopack collections. CONCLUSIONS/SIGNIFICANCE Aedes aegypti abundance was significantly higher in urban than peri-urban neighbourhoods, and their resting behaviour varied between study sites. This fine-scale spatial heterogeneity in Ae. aegypti abundance and behaviour could generate site-specific variation in human exposure and the effectiveness of indoor-based interventions. The trap-dependent nature of associations between Aedes abundance and local DENV incidence indicates further work is needed to identify robust entomological indicators of infection risk.
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Affiliation(s)
- Leonardo D. Ortega-López
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Mauro Pazmiño Betancourth
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Renato León
- Laboratorio de Entomología Médica & Medicina Tropical LEMMT, Colegio de Ciencias Biológicas y Ambientales COCIBA, Universidad San Francisco de Quito USFQ, Quito, Ecuador
| | - Alain Kohl
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Heather M. Ferguson
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, United Kingdom
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Saili K, de Jager C, Masaninga F, Chisanga B, Sinyolo A, Chiwaula J, Chirwa J, Hamainza B, Chanda E, Bakyaita NN, Mutero CM. Community perceptions, acceptability, and the durability of house screening interventions against exposure to malaria vectors in Nyimba district, Zambia. BMC Public Health 2024; 24:285. [PMID: 38267927 PMCID: PMC10809574 DOI: 10.1186/s12889-024-17750-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Accepted: 01/11/2024] [Indexed: 01/26/2024] Open
Abstract
BACKGROUND House screening remains conspicuously absent in national malaria programs despite its recognition by the World Health Organization as a supplementary malaria vector-control intervention. This may be attributed, in part, to the knowledge gap in screen durability or longevity in local climatic conditions and community acceptance under specific cultural practices and socio-economic contexts. The objectives of this study were to assess the durability of window and door wire mesh screens a year after full house screening and to assess the acceptability of the house screening intervention to the participants involved. METHODS This study was conducted in Nyimba district, Zambia and used both quantitative and qualitative methods of data collection and analysis. Both direct observation and questionnaires were employed to assess the durability of the screens and the main reasons for damage. Findings on damage were summarized as percentages. Focus group discussions were used to assess people's knowledge, perceptions, and acceptability of the closing eaves and house screening intervention. Deductive coding and inductive coding were used to analyse the qualitative data. RESULTS A total of 321 out of 400 (80.3%) household owners of screened houses were interviewed. Many window screens (90.3%) were intact. In sharp contrast, most door screens were torn (n = 150; 46.7%) or entirely removed (n = 55; 17.1%). Most doors (n = 114; 76%) had their wire mesh damaged or removed on the bottom half. Goats (25.4%), rust (17.6%) and children (17.1%) were cited most as the cause of damage to door screens. The focus group discussion elicited positive experiences from the participants following the closing of eaves and screening of their windows and doors, ranging from sleeping peacefully due to reduced mosquito biting and/or nuisance and having fewer insects in the house. Participants linked house screening to reduced malaria in their households and community. CONCLUSION This study demonstrated that in rural south-east Zambia, closing eaves and screening windows and doors was widely accepted. Participants perceived that house screening reduced human-vector contact, reduced the malaria burden and nuisance biting from other potentially disease carrying insects. However, screened doors are prone to damage, mainly by children, domestic animals, rust, and termites.
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Affiliation(s)
- Kochelani Saili
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, P.O. Box 30772-00100, Kenya.
- School of Health Systems & Public Health, University of Pretoria Institute for Sustainable Malaria Control, University of Pretoria, Pretoria, South Africa.
| | - Christiaan de Jager
- School of Health Systems & Public Health, University of Pretoria Institute for Sustainable Malaria Control, University of Pretoria, Pretoria, South Africa
| | | | - Brian Chisanga
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, P.O. Box 30772-00100, Kenya
- Development Economics Group, Wageningen University and Research, Wageningen, Netherlands
| | - Andy Sinyolo
- National Malaria Elimination Centre, Lusaka, Zambia
| | | | - Jacob Chirwa
- National Malaria Elimination Centre, Lusaka, Zambia
| | | | - Emmanuel Chanda
- World Health Organization, Regional Office, Brazzaville, Congo
| | | | - Clifford Maina Mutero
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, P.O. Box 30772-00100, Kenya
- School of Health Systems & Public Health, University of Pretoria Institute for Sustainable Malaria Control, University of Pretoria, Pretoria, South Africa
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Fairbanks EL, Saeung M, Pongsiri A, Vajda E, Wang Y, McIver DJ, Richardson JH, Tatarsky A, Lobo NF, Moore SJ, Ponlawat A, Chareonviriyaphap T, Ross A, Chitnis N. Inference for entomological semi-field experiments: Fitting a mathematical model assessing personal and community protection of vector-control interventions. Comput Biol Med 2024; 168:107716. [PMID: 38039890 DOI: 10.1016/j.compbiomed.2023.107716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 09/19/2023] [Accepted: 11/15/2023] [Indexed: 12/03/2023]
Abstract
The effectiveness of vector-control tools is often assessed by experiments as a reduction in mosquito landings using human landing catches (HLCs). However, HLCs alone only quantify a single characteristic and therefore do not provide information on the overall impacts of the intervention product. Using data from a recent semi-field study which used time-stratified HLCs, aspiration of non-landing mosquitoes, and blood feeding, we suggest a Bayesian inference approach for fitting such data to a stochastic model. This model considers both personal protection, through a reduction in biting, and community protection, from mosquito mortality and disarming (prolonged inhibition of blood feeding). Parameter estimates are then used to predict the reduction of vectorial capacity induced by etofenpox-treated clothing, picaridin topical repellents, transfluthrin spatial repellents and metofluthrin spatial repellents, as well as combined interventions for Plasmodium falciparum malaria in Anopleles minimus. Overall, all interventions had both personal and community effects, preventing biting and killing or disarming mosquitoes. This led to large estimated reductions in the vectorial capacity, with substantial impact even at low coverage. As the interventions aged, fewer mosquitoes were killed; however the impact of some interventions changed from killing to disarming mosquitoes. Overall, this inference method allows for additional modes of action, rather than just reduction in biting, to be parameterised and highlights the tools assessed as promising malaria interventions.
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Affiliation(s)
- Emma L Fairbanks
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health, Institute, Allschwill, Switzerland; University of Basel, Basel, Switzerland.
| | - Manop Saeung
- Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok, Thailand
| | - Arissara Pongsiri
- Department of Entomology, Armed Forces Research Institute of Medical Sciences (AFRIMS), Bangkok, Thailand
| | - Elodie Vajda
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health, Institute, Allschwill, Switzerland; University of Basel, Basel, Switzerland; Malaria Elimination Initiative, Institute for Global Health Sciences, University of California, San Francisco, USA
| | - Yuqian Wang
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health, Institute, Allschwill, Switzerland; University of Basel, Basel, Switzerland
| | - David J McIver
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California, San Francisco, USA
| | | | - Allison Tatarsky
- Malaria Elimination Initiative, Institute for Global Health Sciences, University of California, San Francisco, USA
| | | | - Sarah J Moore
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health, Institute, Allschwill, Switzerland; University of Basel, Basel, Switzerland; Vector Control Product Testing Unit, Ifakara Health Institute, Bagamoyo, United Republic of Tanzania; The Nelson Mandela, African Institution of Science and Technology, School of Life Sciences and Bio Engineering, Tengeru, Arusha, United Republic of Tanzania
| | - Alongkot Ponlawat
- Department of Entomology, Armed Forces Research Institute of Medical Sciences (AFRIMS), Bangkok, Thailand
| | | | - Amanda Ross
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health, Institute, Allschwill, Switzerland; University of Basel, Basel, Switzerland
| | - Nakul Chitnis
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health, Institute, Allschwill, Switzerland; University of Basel, Basel, Switzerland
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Deshpande G, Beetch JE, Heller JG, Naqvi OH, Kuhn KG. Assessing the Influence of Climate Change and Environmental Factors on the Top Tick-Borne Diseases in the United States: A Systematic Review. Microorganisms 2023; 12:50. [PMID: 38257877 PMCID: PMC10821204 DOI: 10.3390/microorganisms12010050] [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: 11/28/2023] [Revised: 12/15/2023] [Accepted: 12/19/2023] [Indexed: 01/24/2024] Open
Abstract
In the United States (US), tick-borne diseases (TBDs) have more than doubled in the past fifteen years and are a major contributor to the overall burden of vector-borne diseases. The most common TBDs in the US-Lyme disease, rickettsioses (including Rocky Mountain spotted fever), and anaplasmosis-have gradually shifted in recent years, resulting in increased morbidity and mortality. In this systematic review, we examined climate change and other environmental factors that have influenced the epidemiology of these TBDs in the US while highlighting the opportunities for a One Health approach to mitigating their impact. We searched Medline Plus, PUBMED, and Google Scholar for studies focused on these three TBDs in the US from January 2018 to August 2023. Data selection and extraction were completed using Covidence, and the risk of bias was assessed with the ROBINS-I tool. The review included 84 papers covering multiple states across the US. We found that climate, seasonality and temporality, and land use are important environmental factors that impact the epidemiology and patterns of TBDs. The emerging trends, influenced by environmental factors, emphasize the need for region-specific research to aid in the prediction and prevention of TBDs.
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Affiliation(s)
| | | | | | | | - Katrin Gaardbo Kuhn
- Department of Biostatistics & Epidemiology, Hudson College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (G.D.); (J.E.B.); (J.G.H.); (O.H.N.)
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Kormos A, Dimopoulos G, Bier E, Lanzaro GC, Marshall JM, James AA. Conceptual risk assessment of mosquito population modification gene-drive systems to control malaria transmission: preliminary hazards list workshops. Front Bioeng Biotechnol 2023; 11:1261123. [PMID: 37965050 PMCID: PMC10641379 DOI: 10.3389/fbioe.2023.1261123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 10/09/2023] [Indexed: 11/16/2023] Open
Abstract
The field-testing and eventual adoption of genetically-engineered mosquitoes (GEMs) to control vector-borne pathogen transmission will require them meeting safety criteria specified by regulatory authorities in regions where the technology is being considered for use and other locales that might be impacted. Preliminary risk considerations by researchers and developers may be useful for planning the baseline data collection and field research used to address the anticipated safety concerns. Part of this process is to identify potential hazards (defined as the inherent ability of an entity to cause harm) and their harms, and then chart the pathways to harm and evaluate their probability as part of a risk assessment. The University of California Malaria Initiative (UCMI) participated in a series of workshops held to identify potential hazards specific to mosquito population modification strains carrying gene-drive systems coupled to anti-parasite effector genes and their use in a hypothetical island field trial. The hazards identified were placed within the broader context of previous efforts discussed in the scientific literature. Five risk areas were considered i) pathogens, infections and diseases, and the impacts of GEMs on human and animal health, ii) invasiveness and persistence of GEMs, and interactions of GEMs with target organisms, iii) interactions of GEMs with non-target organisms including horizontal gene transfer, iv) impacts of techniques used for the management of GEMs and v) evolutionary and stability considerations. A preliminary hazards list (PHL) was developed and is made available here. This PHL is useful for internal project risk evaluation and is available to regulators at prospective field sites. UCMI project scientists affirm that the subsequent processes associated with the comprehensive risk assessment for the application of this technology should be driven by the stakeholders at the proposed field site and areas that could be affected by this intervention strategy.
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Affiliation(s)
- Ana Kormos
- Vector Genetics Laboratory, University of California, Davis, Davis, CA, United States
| | - George Dimopoulos
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Malaria Research Institute, Johns Hopkins University, Baltimore, MD, United States
| | - Ethan Bier
- Department of Cell and Developmental Biology, University of California, San Diego, San Diego, CA, United States
| | - Gregory C. Lanzaro
- Vector Genetics Laboratory, University of California, Davis, Davis, CA, United States
| | - John M. Marshall
- Divisions of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, Berkeley, CA, United States
| | - Anthony A. James
- Departments of Microbiology and Molecular Genetics and Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA, United States
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Lopez K, Irwin P, Bron GM, Paskewitz S, Bartholomay L. Ultra-low volume (ULV) adulticide treatment impacts age structure of Culex species (Diptera: Culicidae) in a West Nile virus hotspot. JOURNAL OF MEDICAL ENTOMOLOGY 2023; 60:1108-1116. [PMID: 37473814 DOI: 10.1093/jme/tjad088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 06/01/2023] [Accepted: 07/14/2023] [Indexed: 07/22/2023]
Abstract
West Nile virus (WNV) invaded the continental United States over 20 years ago and continues to cause yearly seasonal outbreaks of human and veterinary disease. In the suburbs of Chicago, Illinois, ultra-low volume (ULV) truck-mounted adulticide spraying frequently is performed to reduce populations of Culex restuans Theobald and Cx. pipiens L. mosquitoes (Diptera: Culicidae) in an effort to lower the risk of WNV transmission. The effectiveness of this control method has not been rigorously evaluated, and evidence for Culex population reduction after ULV adulticide spraying has been inconclusive. Therefore, we evaluated the results of 5 sequential weekly truck-mounted adulticide applications of Zenivex® E20 (etofenprox) in 2 paired sites located in Cook County, IL, during the summer of 2018. Mosquito population abundance, age structure, and WNV infection prevalence were monitored and compared between paired treatment and nearby control sites. Adulticide treatment did not result in consistent short-term or long-term reductions in target WNV vector Culex abundance. However, there was a significant increase in the proportion of nulliparous females in the treated sites compared to control sites and a decrease in Cx. pipiens WNV infection rates at one of the treated sites. This evidence that ULV adulticide spraying altered the age structure and WNV infection prevalence in a vector population has important implications for WNV transmission risk management. Our findings also underscore the importance of measuring these important indicators in addition to abundance metrics when evaluating the efficacy of control methods.
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Affiliation(s)
- Kristina Lopez
- Department of Entomology, University of Wisconsin-Madison, Madison, WI, USA
| | - Patrick Irwin
- Department of Entomology, University of Wisconsin-Madison, Madison, WI, USA
- Northwest Mosquito Abatement District, Wheeling, IL, USA
| | - Gebienna M Bron
- Department of Entomology, University of Wisconsin-Madison, Madison, WI, USA
- Quantitative Veterinary Epidemiology Animal Science Group, Wageningen University and Research, Wageningen, NL, USA
| | - Susan Paskewitz
- Department of Entomology, University of Wisconsin-Madison, Madison, WI, USA
| | - Lyric Bartholomay
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, WI, USA
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Bisia M, Montenegro-Quinoñez CA, Dambach P, Deckert A, Horstick O, Kolimenakis A, Louis VR, Manrique-Saide P, Michaelakis A, Runge-Ranzinger S, Morrison AC. Secondary vectors of Zika Virus, a systematic review of laboratory vector competence studies. PLoS Negl Trop Dis 2023; 17:e0011591. [PMID: 37651473 PMCID: PMC10499269 DOI: 10.1371/journal.pntd.0011591] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 09/13/2023] [Accepted: 08/14/2023] [Indexed: 09/02/2023] Open
Abstract
BACKGROUND After the unprecedented Zika virus (ZIKV) outbreak in the western hemisphere from 2015-2018, Aedes aegypti and Ae. albopictus are now well established primary and secondary ZIKV vectors, respectively. Consensus about identification and importance of other secondary ZIKV vectors remain. This systematic review aims to provide a list of vector species capable of transmitting ZIKV by reviewing evidence from laboratory vector competence (VC) studies and to identify key knowledge gaps and issues within the ZIKV VC literature. METHODS A search was performed until 15th March 2022 on the Cochrane Library, Lilacs, PubMed, Web of Science, WHOLIS and Google Scholar. The search strings included three general categories: 1) "ZIKA"; 2) "vector"; 3) "competence", "transmission", "isolation", or "feeding behavior" and their combinations. Inclusion and exclusion criteria has been predefined and quality of included articles was assessed by STROBE and STROME-ID criteria. FINDINGS From 8,986 articles retrieved, 2,349 non-duplicates were screened by title and abstracts,103 evaluated using the full text, and 45 included in this analysis. Main findings are 1) secondary vectors of interest include Ae. japonicus, Ae. detritus, and Ae. vexans at higher temperature 2) Culex quinquefasciatus was not found to be a competent vector of ZIKV, 3) considerable heterogeneity in VC, depending on the local mosquito strain and virus used in testing was observed. Critical issues or gaps identified included 1) inconsistent definitions of VC parameters across the literature; 2) equivalency of using different mosquito body parts to evaluate VC parameters for infection (mosquito bodies versus midguts), dissemination (heads, legs or wings versus salivary glands), and transmission (detection or virus amplification in saliva, FTA cards, transmission to neonatal mice); 3) articles that fail to use infectious virus assays to confirm the presence of live virus; 4) need for more studies using murine models with immunocompromised mice to infect mosquitoes. CONCLUSION Recent, large collaborative multi-country projects to conduct large scale evaluations of specific mosquito species represent the most appropriate approach to establish VC of mosquito species.
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Affiliation(s)
- Marina Bisia
- Laboratory of Insects and Parasites of Medical Importance, Scientific Directorate of Entomology and Agricultural Zoology, Benaki Phytopathological Institute, Athens, Greece
| | - Carlos Alberto Montenegro-Quinoñez
- Heidelberg Institute of Global Health (HIGH), Faculty of Medicine and University Hospital, Heidelberg University, Heidelberg, Germany
- Instituto de Investigaciones, Centro Universitario de Zacapa, Universidad de San Carlos de Guatemala, Zacapa, Guatemala
| | - Peter Dambach
- Heidelberg Institute of Global Health (HIGH), Faculty of Medicine and University Hospital, Heidelberg University, Heidelberg, Germany
| | - Andreas Deckert
- Heidelberg Institute of Global Health (HIGH), Faculty of Medicine and University Hospital, Heidelberg University, Heidelberg, Germany
| | - Olaf Horstick
- Heidelberg Institute of Global Health (HIGH), Faculty of Medicine and University Hospital, Heidelberg University, Heidelberg, Germany
| | - Antonios Kolimenakis
- Laboratory of Insects and Parasites of Medical Importance, Scientific Directorate of Entomology and Agricultural Zoology, Benaki Phytopathological Institute, Athens, Greece
| | - Valérie R. Louis
- Heidelberg Institute of Global Health (HIGH), Faculty of Medicine and University Hospital, Heidelberg University, Heidelberg, Germany
| | - Pablo Manrique-Saide
- Unidad Colaborativa para Bioensayos Entomológicos (UCBE), Universidad Autónoma de Yucatán, Mérida, México
| | - Antonios Michaelakis
- Laboratory of Insects and Parasites of Medical Importance, Scientific Directorate of Entomology and Agricultural Zoology, Benaki Phytopathological Institute, Athens, Greece
| | - Silvia Runge-Ranzinger
- Heidelberg Institute of Global Health (HIGH), Faculty of Medicine and University Hospital, Heidelberg University, Heidelberg, Germany
| | - Amy C. Morrison
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California Davis, Davis, California, United States of America
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Hobbs NP, Weetman D, Hastings IM. Insecticide resistance management strategies for public health control of mosquitoes exhibiting polygenic resistance: A comparison of sequences, rotations, and mixtures. Evol Appl 2023; 16:936-959. [PMID: 37124088 PMCID: PMC10130562 DOI: 10.1111/eva.13546] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 02/22/2023] [Accepted: 03/21/2023] [Indexed: 05/02/2023] Open
Abstract
Malaria control uses insecticides to kill Anopheles mosquitoes. Recent successes in malaria control are threatened by increasing levels of insecticide resistance (IR), requiring insecticide resistance management (IRM) strategies to mitigate this problem. Field trials of IRM strategies are usually prohibitively expensive with long timeframes, and mathematical modeling is often used to evaluate alternative options. Previous IRM models in the context of malaria control assumed IR to have a simple (monogenic) basis, whereas in natural populations, IR will often be a complex polygenic trait determined by multiple genetic variants. A quantitative genetics model was developed to model IR as a polygenic trait. The model allows insecticides to be deployed as sequences (continuous deployment until a defined withdrawal threshold, termed "insecticide lifespan", as indicated by resistance diagnosis in bioassays), rotations (periodic switching of insecticides), or full-dose mixtures (two insecticides in one formulation). These IRM strategies were compared based on their "strategy lifespan" (capped at 500 generations). Partial rank correlation and generalized linear modeling was used to identify and quantify parameters driving the evolution of resistance. Random forest models were used to identify parameters offering predictive value for decision-making. Deploying single insecticides as sequences or rotations usually made little overall difference to their "strategy lifespan", though rotations displayed lower mean and peak resistances. Deploying two insecticides in a full-dose mixture formulation was found to extend the "strategy lifespan" when compared to deploying each in sequence or rotation. This pattern was observed regardless of the level of cross resistance between the insecticides or the starting level of resistance. Statistical analysis highlighted the importance of insecticide coverage, cross resistance, heritability, and fitness costs for selecting an appropriate IRM strategy. Full-dose mixtures appear the most promising of the strategies evaluated, with the longest "strategy lifespans". These conclusions broadly corroborate previous results from monogenic models.
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Affiliation(s)
- Neil Philip Hobbs
- Department of Vector BiologyLiverpool School of Tropical MedicinePembroke PlaceLiverpoolL3 5QAUK
| | - David Weetman
- Department of Vector BiologyLiverpool School of Tropical MedicinePembroke PlaceLiverpoolL3 5QAUK
| | - Ian Michael Hastings
- Department of Tropical Disease BiologyLiverpool School of Tropical MedicinePembroke PlaceLiverpoolL3 5QAUK
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Jaffal A, Fite J, Baldet T, Delaunay P, Jourdain F, Mora-Castillo R, Olive MM, Roiz D. Current evidences of the efficacy of mosquito mass-trapping interventions to reduce Aedes aegypti and Aedes albopictus populations and Aedes-borne virus transmission. PLoS Negl Trop Dis 2023; 17:e0011153. [PMID: 36877728 PMCID: PMC10032496 DOI: 10.1371/journal.pntd.0011153] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 03/22/2023] [Accepted: 02/08/2023] [Indexed: 03/07/2023] Open
Abstract
BACKGROUND Over the past decades, several viral diseases transmitted by Aedes mosquitoes-dengue, chikungunya, Zika-have spread outside of tropical areas. To limit the transmission of these viruses and preserve human health, the use of mosquito traps has been developed as a complement or alternative to other vector control techniques. The objective of this work was to perform a systematic review of the existing scientific literature to assess the efficacy of interventions based on adult mosquito trap to control Aedes population densities and the diseases they transmit worldwide. METHODS AND FINDINGS Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic review was conducted using the PubMed and Scopus databases. Among the 19 selected papers, lethal ovitraps were used in 16 studies, host-seeking female traps in 3 studies. Furthermore, 16 studies focused on the control of Ae. aegypti. Our review showed great heterogeneity in the indicators used to assess trap efficacy: e.g., the number of host-seeking females, the number of gravid females, the proportion of positive containers, the viral infection rate in female mosquitoes or serological studies in residents. Regardless of the type of studied traps, the results of various studies support the efficacy of mass trapping in combination with classical integrated vector control in reducing Aedes density. More studies with standardized methodology, and indicators are urgently needed to provide more accurate estimates of their efficacy. CONCLUSIONS This review highlights gaps in the demonstration of the efficacy of mass trapping of mosquitoes in reducing viral transmission and disease. Thus, further large-scale cluster randomized controlled trials conducted in endemic areas and including epidemiological outcomes are needed to establish scientific evidence for the reduction of viral transmission risk by mass trapping targeting gravid and/or host-seeking female mosquitoes.
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Affiliation(s)
- Ali Jaffal
- French Agency for Food, Environmental and Occupational Health & Safety (Anses), Maisons-Alfort, France
| | - Johanna Fite
- French Agency for Food, Environmental and Occupational Health & Safety (Anses), Maisons-Alfort, France
| | - Thierry Baldet
- ASTRE (Animal, Santé, Territoires, Risques, Ecosystèmes), CIRAD, Univ Montpellier, Montpellier, France
| | - Pascal Delaunay
- Service de Parasitologie-Mycologie, Hôpital L'Archet, Centre Hospitalier Universitaire de Nice, UCA, Nice, France
| | - Frédéric Jourdain
- Santé publique France (French National Public Health Agency), Montpellier, France
- MIVEGEC, IRD, CNRS, Université Montpellier, Montpellier, France
| | | | - Marie-Marie Olive
- ASTRE (Animal, Santé, Territoires, Risques, Ecosystèmes), CIRAD, Univ Montpellier, Montpellier, France
- MIVEGEC, IRD, CNRS, Université Montpellier, Montpellier, France
| | - David Roiz
- MIVEGEC, IRD, CNRS, Université Montpellier, Montpellier, France
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Morrison AC, Paz-Soldan VA, Vazquez-Prokopec GM, Lambrechts L, Elson WH, Barrera P, Astete H, Briesemeister V, Leguia M, Jenkins SA, Long KC, Kawiecki AB, Reiner RC, Perkins TA, Lloyd AL, Waller LA, Hontz RD, Stoddard ST, Barker CM, Kitron U, Elder JP, Rothman AL, Scott TW. Quantifying heterogeneities in arbovirus transmission: Description of the rationale and methodology for a prospective longitudinal study of dengue and Zika virus transmission in Iquitos, Peru (2014-2019). PLoS One 2023; 18:e0273798. [PMID: 36730229 PMCID: PMC9894416 DOI: 10.1371/journal.pone.0273798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 08/15/2022] [Indexed: 02/03/2023] Open
Abstract
Current knowledge of dengue virus (DENV) transmission provides only a partial understanding of a complex and dynamic system yielding a public health track record that has more failures than successes. An important part of the problem is that the foundation for contemporary interventions includes a series of longstanding, but untested, assumptions based on a relatively small portion of the human population; i.e., people who are convenient to study because they manifest clinically apparent disease. Approaching dengue from the perspective of people with overt illness has produced an extensive body of useful literature. It has not, however, fully embraced heterogeneities in virus transmission dynamics that are increasingly recognized as key information still missing in the struggle to control the most important insect-transmitted viral infection of humans. Only in the last 20 years have there been significant efforts to carry out comprehensive longitudinal dengue studies. This manuscript provides the rationale and comprehensive, integrated description of the methodology for a five-year longitudinal cohort study based in the tropical city of Iquitos, in the heart of the Peruvian Amazon. Primary data collection for this study was completed in 2019. Although some manuscripts have been published to date, our principal objective here is to support subsequent publications by describing in detail the structure, methodology, and significance of a specific research program. Our project was designed to study people across the entire continuum of disease, with the ultimate goal of quantifying heterogeneities in human variables that affect DENV transmission dynamics and prevention. Because our study design is applicable to other Aedes transmitted viruses, we used it to gain insights into Zika virus (ZIKV) transmission when during the project period ZIKV was introduced and circulated in Iquitos. Our prospective contact cluster investigation design was initiated by detecttion of a person with a symptomatic DENV infection and then followed that person's immediate contacts. This allowed us to monitor individuals at high risk of DENV infection, including people with clinically inapparent and mild infections that are otherwise difficult to detect. We aimed to fill knowledge gaps by defining the contribution to DENV transmission dynamics of (1) the understudied majority of DENV-infected people with inapparent and mild infections and (2) epidemiological, entomological, and socio-behavioral sources of heterogeneity. By accounting for factors underlying variation in each person's contribution to transmission we sought to better determine the type and extent of effort needed to better prevent virus transmission and disease.
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Affiliation(s)
- Amy C. Morrison
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, Davis, California, United States of America
- * E-mail: ,
| | - Valerie A. Paz-Soldan
- Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, New Orleans, Lousiana, United States of America
| | | | - Louis Lambrechts
- Institut Pasteur, Université Paris Cité, CNRS UMR2000, Insect-Virus Interactions Unit, Paris, France
| | - William H. Elson
- Department of Entomology and Nematology, University of California Davis, Davis, California, United States of America
| | - Patricia Barrera
- Department of Entomology and Nematology, University of California Davis, Davis, California, United States of America
- Genomics Laboratory, Pontificia Universidad Católica del Peru, Lima, Peru
| | - Helvio Astete
- Virology and Emerging Infections Department, United States Naval Medical Research Unit No. 6, Lima, Peru
- Department of Entomology, United States Naval Medical Research Unit No. 6, Lima, Peru
| | - Veronica Briesemeister
- Department of Entomology and Nematology, University of California Davis, Davis, California, United States of America
| | - Mariana Leguia
- Genomics Laboratory, Pontificia Universidad Católica del Peru, Lima, Peru
| | - Sarah A. Jenkins
- Virology and Emerging Infections Department, United States Naval Medical Research Unit No. 6, Lima, Peru
| | - Kanya C. Long
- Department of Family Medicine and Public Health, University of California San Diego School of Medicine, La Jolla, California, United States of America
| | - Anna B. Kawiecki
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, Davis, California, United States of America
| | - Robert C. Reiner
- University of Washington, Seattle, Washington, United States of America
| | - T. Alex Perkins
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Alun L. Lloyd
- Biomathematics Graduate Program and Department of Mathematics, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Lance A. Waller
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America
| | - Robert D. Hontz
- Virology and Emerging Infections Department, United States Naval Medical Research Unit No. 6, Lima, Peru
| | - Steven T. Stoddard
- School of Public Health, San Diego State University, San Diego, California, United States of America
| | - Christopher M. Barker
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, Davis, California, United States of America
| | - Uriel Kitron
- Institut Pasteur, Université Paris Cité, CNRS UMR2000, Insect-Virus Interactions Unit, Paris, France
| | - John P. Elder
- School of Public Health, San Diego State University, San Diego, California, United States of America
| | - Alan L. Rothman
- Institute for Immunology and Informatics and Department of Cell and Molecular Biology, University of Rhode Island, Providence, Rhode Island, United States of America
| | - Thomas W. Scott
- Department of Entomology and Nematology, University of California Davis, Davis, California, United States of America
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11
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Bottino-Rojas V, James AA. Use of Insect Promoters in Genetic Engineering to Control Mosquito-Borne Diseases. Biomolecules 2022; 13:biom13010016. [PMID: 36671401 PMCID: PMC9855440 DOI: 10.3390/biom13010016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 12/16/2022] [Accepted: 12/18/2022] [Indexed: 12/24/2022] Open
Abstract
Mosquito transgenesis and gene-drive technologies provide the basis for developing promising new tools for vector-borne disease prevention by either suppressing wild mosquito populations or reducing their capacity from transmitting pathogens. Many studies of the regulatory DNA and promoters of genes with robust sex-, tissue- and stage-specific expression profiles have supported the development of new tools and strategies that could bring mosquito-borne diseases under control. Although the list of regulatory elements available is significant, only a limited set of those can reliably drive spatial-temporal expression. Here, we review the advances in our ability to express beneficial and other genes in mosquitoes, and highlight the information needed for the development of new mosquito-control and anti-disease strategies.
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Affiliation(s)
- Vanessa Bottino-Rojas
- Department of Microbiology and Molecular Genetics, University of California, Irvine, CA 92697, USA
| | - Anthony A. James
- Department of Microbiology and Molecular Genetics, University of California, Irvine, CA 92697, USA
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, USA
- Correspondence:
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12
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Msoffe R, Hewitt M, Masalu JP, Finda M, Kavishe DR, Okumu FO, Mpolya EA, Kaindoa EW, Killeen GF. Participatory development of practical, affordable, insecticide-treated mosquito proofing for a range of housing designs in rural southern Tanzania. Malar J 2022; 21:318. [PMCID: PMC9636681 DOI: 10.1186/s12936-022-04333-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 10/18/2022] [Indexed: 11/08/2022] Open
Abstract
Abstract
Background
Insecticidal mosquito-proof netting screens could combine the best features of insecticide-treated nets (ITNs) and indoor residual spraying (IRS), the two most important front line vector control interventions in Africa today, and also overcome the most important limitations of these methods. This study engaged members of a rural Tanzanian community in developing and evaluating simple, affordable and scalable procedures for installing readily available screening materials on eave gaps and windows of their own houses, and then treating those screens with a widely used IRS formulation of the organophosphate insecticide pirimiphos-methyl (PM).
Methods
A cohort of 54 households recruited upon consent, following which the structural features and occupant demographics of their houses were surveyed. Indoor mosquito densities were surveyed longitudinally, for approximately 3 months before and over 5 months after participatory house modification and screening using locally available materials. Each house was randomly assigned to one of three study arms: (1) No screens installed until the end of the study (negative control), (2) untreated screens installed, and (3) screened installed and then treated with PM, the insecticidal activity of which was subsequently assessed using standard cone assays.
Results
Almost all (52) recruited households participated until the end, at which point all houses had been successfully screened. In most cases, screening was only installed after making enabling structural modifications that were accepted by the enrolled households. Compared to unscreened houses, houses with either treated or untreated screens both almost entirely excluded Anopheles arabiensis (Relative reduction (RR) ≥ 98%, P < < 0.0001), the most abundant local malaria vector. However, screens were far less effective against Culex quinquefasciatus (RR ≤ 46%, P < < 0.0001), a non-malaria vector causing considerable biting nuisance, regardless of their treatment status. While PM did not augment household level protection by screens against either mosquito species (P = 0.676 and 0.831, respectively), 8 months after treatment it still caused 73% and 89% mortality among susceptible insectary-reared Anopheles gambiae following exposures of 3 and 30 min, respectively.
Conclusions
Participatory approaches to mosquito proofing houses may be acceptable and effective, and installed screens may be suitable targets for residual insecticide treatments.
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13
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Elson WH, Kawiecki AB, Donnelly MAP, Noriega AO, Simpson JK, Syafruddin D, Rozi IE, Lobo NF, Barker CM, Scott TW, Achee NL, Morrison AC. Use of mobile data collection systems within large-scale epidemiological field trials: findings and lessons-learned from a vector control trial in Iquitos, Peru. BMC Public Health 2022; 22:1924. [PMID: 36243698 PMCID: PMC9571464 DOI: 10.1186/s12889-022-14301-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 10/05/2022] [Indexed: 11/25/2022] Open
Abstract
Vector-borne diseases are among the most burdensome infectious diseases worldwide with high burden to health systems in developing regions in the tropics. For many of these diseases, vector control to reduce human biting rates or arthropod populations remains the primary strategy for prevention. New vector control interventions intended to be marketed through public health channels must be assessed by the World Health Organization for public health value using data generated from large-scale trials integrating epidemiological endpoints of human health impact. Such phase III trials typically follow large numbers of study subjects to meet necessary power requirements for detecting significant differences between treatment arms, thereby generating substantive and complex datasets. Data is often gathered directly in the field, in resource-poor settings, leading to challenges in efficient data reporting and/or quality assurance. With advancing technology, mobile data collection (MDC) systems have been implemented in many studies to overcome these challenges. Here we describe the development and implementation of a MDC system during a randomized-cluster, placebo-controlled clinical trial evaluating the protective efficacy of a spatial repellent intervention in reducing human infection with Aedes-borne viruses (ABV) in the urban setting of Iquitos, Peru, as well as the data management system that supported it. We discuss the benefits, remaining capacity gaps and the key lessons learned from using a MDC system in this context in detail.
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Affiliation(s)
| | | | | | | | | | - Din Syafruddin
- Eijkman Institute for Molecular Biology, Jakarta, Indonesia
| | | | - Neil F Lobo
- Department of Biological Sciences, Eck Institute for Global Health, Notre Dame, IND, USA
| | | | | | - Nicole L Achee
- Department of Biological Sciences, Eck Institute for Global Health, Notre Dame, IND, USA
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14
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Sawalha S, Al-Jawabreh A, Hjaija D, Ereqat S, Nasereddin A, Al-Jawabreh H, Evlampidou I. Effectiveness of insecticide thermal fogging in hyrax dens in the control of leishmaniasis vectors in rural Palestine: A prospective study. PLoS Negl Trop Dis 2022; 16:e0010628. [PMID: 36099245 PMCID: PMC9469989 DOI: 10.1371/journal.pntd.0010628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 07/01/2022] [Indexed: 11/18/2022] Open
Abstract
Background
Zoonotic cutaneous leishmaniasis (ZCL) is endemic in Palestine and transmitted by Phlebotomus sand flies. They inhabit dens of hyraxes, the reservoir animal. Control measures were implemented since 1996 but cases still occur. We estimated the effect of insecticide thermal fogging inside hyrax dens on sand fly density and leishmania infection.
Methodology/Principal findings
During July-September 2019, we conducted a 12-week controlled interrupted time series study in two control and one intervention sites containing three hyrax dens each. We implemented Permethrin thermal fogging in the intervention site at week 6. We measured weekly and 36hrs post-intervention sand fly abundance inside dens using CDC light traps. We performed Next-Generation Sequencing to identify sand fly Leishmania spp. infection. We calculated the abundance reduction (AR) using Mulla’s formula and negative binomial regression. Among 11427 collected sand flies, 7339 (64%) were females and 1786 (16%) were Phlebotomus spp. comprising ten species; P. sergenti was the dominant (n = 773, 43%). We report P. arabicus (n = 6) for the first time in Palestine. After fogging, Phlebotomus spp. AR was 93% at 36hrs, 18% and 38% at two and five weeks respectively and 41% during the complete post-intervention period. In the regression models, Phlebotomus spp. density in the intervention site decreased by 74% (IRR: 0.26, 95%CI: 0.11–0.57) at two weeks, 34% (IRR: 0.66, 95%CI: 0.48–0.90) at five weeks and 74% (IRR: 0.26, 95%CI: 0.12–0.59) during the complete period. The density of Leishmania infected sand flies decreased by 65% (IRR: 0.35, 95%CI: 0.26–0.48) at five weeks and 82% (IRR: 0.18, 95%CI: 0.07–0.42) for the complete period (zero infections until week two). Leishmania infection prevalence in the intervention site was 14% pre-intervention and 3.9% post-intervention.
Conclusions/Significance
Fogging hyrax dens reduced sand fly abundance and leishmania infection during the 5-week post-intervention period and especially the first two weeks suggesting it could be an effective source-reduction measure for ZCL vectors. Future randomized controlled trials are needed to confirm the effectiveness of fogging hyrax dens on decreasing ZCL incidence.
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Affiliation(s)
- Samer Sawalha
- Vector Control Unit, Environmental Health Department, Ministry of Health, Ramallah, Palestine
- Mediterranean and Black Sea Field Epidemiology Training Programme—MediPIET, Madrid, Spain
| | - Amer Al-Jawabreh
- Leishmaniases Research Unit, Jericho, Palestine
- Arab American University, Jenin, Palestine
- * E-mail:
| | - Dea Hjaija
- Preventive Medicine Department, Ministry of Health, Ramallah, Palestine
| | - Suheir Ereqat
- Biochemistry and Molecular Biology Department, Faculty of Medicine, Al-Quds University, East Jerusalem, Palestine
| | - Abdelmajeed Nasereddin
- Biochemistry and Molecular Biology Department, Faculty of Medicine, Al-Quds University, East Jerusalem, Palestine
| | | | - Iro Evlampidou
- Mediterranean and Black Sea Field Epidemiology Training Programme—MediPIET, Madrid, Spain
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15
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Gürtler RE, Laiño MA, Alvedro A, Enriquez GF, Macchiaverna NP, Gaspe MS, Cardinal MV. Treatment of dogs with fluralaner reduced pyrethroid-resistant Triatoma infestans abundance, Trypanosoma cruzi infection and human-triatomine contact in the Argentine Chaco. Parasit Vectors 2022; 15:257. [PMID: 35831874 PMCID: PMC9277862 DOI: 10.1186/s13071-022-05343-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 05/23/2022] [Indexed: 11/16/2022] Open
Abstract
Background Triatomine elimination efforts and the interruption of domestic transmission of Trypanosoma cruzi are hampered by pyrethroid resistance. Fluralaner, a long-lasting ectoparasiticide administered to dogs, substantially reduced site infestation and abundance of pyrethroid-resistant Triatoma infestans Klug (Heteroptera: Reduviidae) in an ongoing 10-month trial in Castelli (Chaco Province, Argentina). We assessed the effects of fluralaner on vector infection with T. cruzi and blood meal sources stratified by ecotope and quantified its medium-term effects on site infestation and triatomine abundance. Methods We conducted a placebo-controlled, before-and-after efficacy trial of fluralaner in 28 infested sites over a 22-month period. All dogs received either an oral dose of fluralaner (treated group) or placebo (control group) at 0 month post-treatment [MPT]. Placebo-treated dogs were rescue-treated with fluralaner at 1 MPT, as were all eligible dogs at 7 MPT. Site-level infestation and abundance were periodically assessed by timed manual searches with a dislodging aerosol. Vector infection was mainly determined by kDNA-PCR and blood meal sources were determined by enzyme-linked immunosorbent assay. Results In fluralaner-treated households, site infestation dropped from 100% at 0 MPT to 18–19% over the period 6–22 MPT while mean abundance plummeted from 5.5 to 0.6 triatomines per unit effort. In control households, infestation dropped similarly post-treatment. The overall prevalence of T. cruzi infection steadily decreased from 13.8% at 0–1 MPT (baseline) to 6.4% and subsequently 2.3% thereafter, while in domiciles, kitchens and storerooms it dropped from 17.4% to 4.7% and subsequently 3.3% thereafter. Most infected triatomines occurred in domiciles and had fed on humans. Infected-bug abundance plummeted after fluralaner treatment and remained marginal or nil thereafter. The human blood index of triatomines collected in domiciles, kitchens and storerooms highly significantly fell from 42.9% at baseline to 5.3–9.1% over the period 6–10 MPT, increasing to 36.8% at 22 MPT. Dog blood meals occurred before fluralaner administration only. The cat blood index increased from 9.9% at baseline to 57.9–72.7% over the period 6–10 MPT and dropped to 5.3% at 22 MPT, whereas chicken blood meals rose from 39.6% to 63.2–88.6%. Conclusion Fluralaner severely impacted infestation- and transmission-related indices over nearly 2 years, causing evident effects at 1 MPT, and deserves larger efficacy trials. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-022-05343-2.
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Affiliation(s)
- Ricardo Esteban Gürtler
- Laboratory of Eco-Epidemiology, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina. .,Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina.
| | - Mariano Alberto Laiño
- Laboratory of Eco-Epidemiology, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina.,Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina
| | - Alejandra Alvedro
- Laboratory of Eco-Epidemiology, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina.,Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina
| | - Gustavo Fabián Enriquez
- Laboratory of Eco-Epidemiology, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina.,Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina
| | - Natalia Paula Macchiaverna
- Laboratory of Eco-Epidemiology, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina.,Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina
| | - María Sol Gaspe
- Laboratory of Eco-Epidemiology, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina.,Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina
| | - Marta Victoria Cardinal
- Laboratory of Eco-Epidemiology, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina. .,Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina.
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16
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Schwartz AM, Mackeprang JM, Mead PS, Hinckley AF. Effectiveness of personal protection measures against Lyme disease: A review of epidemiologic studies from the United States. Zoonoses Public Health 2022; 69:777-791. [PMID: 35791092 DOI: 10.1111/zph.12984] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 05/11/2022] [Accepted: 06/22/2022] [Indexed: 11/29/2022]
Abstract
Lyme disease, the most commonly reported vector-borne disease in the United States, is caused by the bacteria Borrelia burgdorferi and is transmitted through the bite of an infected blacklegged tick. In the absence of a licensed vaccine, the prevention of Lyme disease relies heavily on limiting tick exposure. Methods for limiting tick exposure include personal protection measures such as repellent use, wearing protective clothing, avoiding areas where ticks may be present, bathing after exposure to tick habitat and performing regular tick checks. Public health officials typically recommend all these personal protection measures; however, there is limited evidence to promote one behaviour or practice over another. The focus of this article is to review available literature that examines the effectiveness of recommended personal protection measures to prevent Lyme and other Ixodes-transmitted diseases in humans. Articles included in this review were identified through Google Scholar and PubMed searches using specific search terms. We identified over 56,000 articles using Google Scholar and PubMed searches. Of those, 16 studies fit our criteria for inclusion and were reviewed in their entirety. Among the personal protection measures evaluated, no intervention was predominantly or consistently effective across studies, demonstrating that, currently, there is no single best method for primary prevention of Ixodes-transmitted diseases in the United States. Frequently recommended practices such as tick checks, repellent use and protective clothing had mixed results across studies. Study design differences limited comparability among studies, and sample sizes for these studies may have been too small to detect statistically significant results even if a prevention method was effective. Though many of the reviewed personal protection measures are frequently recommended to the public, limited evidence demonstrates their ability to prevent tick-borne disease. Additional standardized studies are needed to evaluate personal protection measures.
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Affiliation(s)
- Amy M Schwartz
- Bacterial Diseases Branch, Division of Vector Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Fort Collins, Colorado, USA
| | - Julia Montague Mackeprang
- Bacterial Diseases Branch, Division of Vector Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Fort Collins, Colorado, USA.,Association of Schools of Public Health (ASPH), Washington, DC, USA
| | - Paul S Mead
- Bacterial Diseases Branch, Division of Vector Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Fort Collins, Colorado, USA
| | - Alison F Hinckley
- Bacterial Diseases Branch, Division of Vector Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Fort Collins, Colorado, USA
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17
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Robinson A, Gomes LRDO, Abdurahman OS, Alemayehu W, Shuka G, Melese E, Guye M, Legesse D, Elias E, Temam K, Koro KH, Adugna D, Seife F, Aga MA, Sarah V, Lambert SM, Walker SL, Habtamu E, Solomon AW, Last A, Macleod D, Burton MJ, Logan JG. Evaluation of the efficacy of insecticide-treated scarves to protect children from the trachoma vector Musca sorbens (Diptera: Muscidae): A phase II randomised controlled trial in Oromia, Ethiopia. EClinicalMedicine 2022; 49:101487. [PMID: 35747196 PMCID: PMC9189873 DOI: 10.1016/j.eclinm.2022.101487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 05/05/2022] [Accepted: 05/16/2022] [Indexed: 11/18/2022] Open
Abstract
Background The eye-seeking fly Musca sorbens can act as a vector for ocular Chlamydia trachomatis, causing trachoma, yet there has been very little research on control measures. We investigated whether insect repellent products, specifically insecticide-treated clothing, could provide personal protection to the user from eye-seeking flies. Methods We first conducted a series of phase I laboratory studies to inform our choice of field intervention. We then conducted a phase II randomised controlled trial testing the efficacy of permethrin-treated scarves (PTS) in reducing fly-face contact in Oromia, Ethiopia. Children aged 4-10 years in full health and with no known adverse reactions to permethrin or other insecticides were allocated to either arm using restricted randomisation. Intervention arm children wore Insect Shield® versatile wraps (as PTS) for 28 days. The primary outcomes, fly-eye, -nose and -mouth contact, were assessed on the first day (0/30/60/180 minutes), on day 7 and on day 28. All participants present per timepoint were included in analyses. This trial was registered with ClinicalTrials.gov (NCT03813069). Findings Participants were recruited to the field trial between 29/10/2019 and 01/11/2019, 58 were randomised to test or control arm. More fly (-eye, -nose and -mouth) contacts were observed in the PTS arm at baseline. After adjusting for baseline contact rates, across all timepoints there was a 35% decrease in fly-eye contacts in the PTS relative to control arm (rate ratio [RR] 0.65, 95% CI 0.52-0.83). Similar cross-timepoint reductions were seen for fly-nose and fly-mouth contacts (RR 0.69, 95% CI 0.51-0.92 and RR 0.79, 95% CI 0.62-1.01, respectively). All children were included on day 0. Two in the control arm were absent on day 7, one left the study and four were excluded from analysis at day 28. No adverse events occurred in the trial. Interpretation Musca sorbens flies are sufficiently repelled by PTS to reduce fly-eye contacts for the wearer, thus possibly reducing the risk of trachoma transmission. Permethrin-treated scarves may therefore an alternative to insecticide space spraying for protection from these flies. Funding Wellcome Trust.
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Affiliation(s)
- Ailie Robinson
- Department of Disease Control, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Laura Reis de Oliveira Gomes
- Department of Disease Control, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Oumer Shafi Abdurahman
- The Fred Hollows Foundation, P.O. Box 6307, Addis Ababa, Ethiopia
- International Centre for Eye Health, Department of Clinical Research, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Wondu Alemayehu
- The Fred Hollows Foundation, P.O. Box 6307, Addis Ababa, Ethiopia
| | - Gemeda Shuka
- The Fred Hollows Foundation, P.O. Box 6307, Addis Ababa, Ethiopia
| | - Ewunetu Melese
- The Fred Hollows Foundation, P.O. Box 6307, Addis Ababa, Ethiopia
| | - Meseret Guye
- The Fred Hollows Foundation, P.O. Box 6307, Addis Ababa, Ethiopia
| | - Demitu Legesse
- The Fred Hollows Foundation, P.O. Box 6307, Addis Ababa, Ethiopia
| | - Eden Elias
- The Fred Hollows Foundation, P.O. Box 6307, Addis Ababa, Ethiopia
| | - Kedir Temam
- The Fred Hollows Foundation, P.O. Box 6307, Addis Ababa, Ethiopia
| | - Korso Hirpo Koro
- The Fred Hollows Foundation, P.O. Box 6307, Addis Ababa, Ethiopia
| | - Dereje Adugna
- Oromia Regional Health Bureau, Addis Ababa, Ethiopia
| | - Fikre Seife
- The Ethiopian Federal Ministry of Health, Disease Prevention and Control Directorate, Addis Ababa, Ethiopia
| | | | - Virginia Sarah
- Global Partnerships Executive, The Fred Hollows Foundation, 12-15 Crawford Mews, York Street, London W1H1LX
| | - Saba M. Lambert
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Stephen L. Walker
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Esmael Habtamu
- International Centre for Eye Health, Department of Clinical Research, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Anthony W. Solomon
- Department of Control of Neglected Tropical Diseases, World Health Organization, Avenue Appia 20, 1202 Genève, Switzerland
| | - Anna Last
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - David Macleod
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Matthew J. Burton
- International Centre for Eye Health, Department of Clinical Research, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
- National Institute for Health Research Biomedical Research Centre for Ophthalmology, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK
| | - James G. Logan
- Department of Disease Control, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
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Dufault SM, Tanamas SK, Indriani C, Utarini A, Ahmad RA, Jewell NP, Simmons CP, Anders KL. Disruption of spatiotemporal clustering in dengue cases by wMel Wolbachia in Yogyakarta, Indonesia. Sci Rep 2022; 12:9890. [PMID: 35701454 PMCID: PMC9198086 DOI: 10.1038/s41598-022-13749-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 05/27/2022] [Indexed: 10/25/2022] Open
Abstract
Dengue exhibits focal clustering in households and neighborhoods, driven by local mosquito population dynamics, human population immunity, and fine scale human and mosquito movement. We tested the hypothesis that spatiotemporal clustering of homotypic dengue cases is disrupted by introduction of the arbovirus-blocking bacterium Wolbachia (wMel-strain) into the Aedes aegypti mosquito population. We analysed 318 serotyped and geolocated dengue cases (and 5921 test-negative controls) from a randomized controlled trial in Yogyakarta, Indonesia of wMel deployments. We find evidence of spatial clustering up to 300 m among the 265 dengue cases (3083 controls) in the untreated trial arm. Participant pairs enrolled within 30 days and 50 m had a 4.7-fold increase (compared to 95% CI on permutation-based null distribution: 0.1, 1.2) in the odds of being homotypic (i.e. potentially transmission-related) as compared to pairs occurring at any distance. In contrast, we find no evidence of spatiotemporal clustering among the 53 dengue cases (2838 controls) resident in the wMel-treated arm. Introgression of wMel Wolbachia into Aedes aegypti mosquito populations interrupts focal dengue virus transmission leading to reduced case incidence; the true intervention effect may be greater than the 77% efficacy measured in the primary analysis of the Yogyakarta trial.
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Affiliation(s)
- Suzanne M. Dufault
- grid.47840.3f0000 0001 2181 7878Division of Biostatistics, School of Public Health, University of California, Berkeley, Berkeley, USA
| | - Stephanie K. Tanamas
- grid.1002.30000 0004 1936 7857World Mosquito Program, Institute of Vector-borne Disease, Monash University, Clayton, 3800 Australia
| | - Citra Indriani
- grid.8570.a0000 0001 2152 4506World Mosquito Program Yogyakarta, Centre for Tropical Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, 55281 Indonesia
| | - Adi Utarini
- grid.8570.a0000 0001 2152 4506World Mosquito Program Yogyakarta, Centre for Tropical Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, 55281 Indonesia
| | - Riris Andono Ahmad
- grid.8570.a0000 0001 2152 4506World Mosquito Program Yogyakarta, Centre for Tropical Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, 55281 Indonesia
| | - Nicholas P. Jewell
- grid.47840.3f0000 0001 2181 7878Division of Biostatistics, School of Public Health, University of California, Berkeley, Berkeley, USA ,grid.8991.90000 0004 0425 469XLondon School of Hygiene and Tropical Medicine, Bloomsbury, London, WC1E 7HT UK
| | - Cameron P. Simmons
- grid.1002.30000 0004 1936 7857World Mosquito Program, Institute of Vector-borne Disease, Monash University, Clayton, 3800 Australia
| | - Katherine L. Anders
- grid.1002.30000 0004 1936 7857World Mosquito Program, Institute of Vector-borne Disease, Monash University, Clayton, 3800 Australia
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19
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Laiño MA, Cardinal MV, Gaspe MS, Enriquez GF, Alvedro A, Macchiaverna NP, Gürtler RE. Control of pyrethroid-resistant populations of Triatoma infestans, the main vector of Trypanosoma cruzi, by treating dogs with fluralaner in the Argentine Chaco. MEDICAL AND VETERINARY ENTOMOLOGY 2022; 36:149-158. [PMID: 34866216 DOI: 10.1111/mve.12561] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 11/12/2021] [Accepted: 11/24/2021] [Indexed: 06/13/2023]
Abstract
We assessed whether fluralaner administered to outbred healthy dogs reduced or supressed site infestation and abundance of pyrethroid-resistant populations of Triatoma infestans Klug (Heteroptera: Reduviidae). We conducted a placebo-controlled before-and-after efficacy trial in 28 infested sites in Castelli (Argentine Chaco) over 10 months. All 72 dogs initially present received either an oral dose of fluralaner (treated group) or placebo (control group) at month 0 posttreatment (MPT). Preliminary results justified treating all 38 control-house dogs with fluralaner 1 month later, and 71 of 78 existing dogs at 7 MPT. Site-level infestation and triatomine abundance were evaluated using timed manual searches with a dislodging aerosol. In the fluralaner-treated group, infestation dropped significantly from 100% at baseline to 19% over 6-10 MPT whereas mean abundance fell highly significantly from 5.5 to 0.8-0.9 triatomines per unit effort. In the placebo group, site infestation and mean abundance remained stable between 0 and 1 MPT, and strongly declined after fluralaner administration from 13.0-14.7 - triatomines at 0-1 MPT to 4.0-4.2 over 6-10 MPT. Only one of 81 noninfested sites before fluralaner treatment became infested subsequently. Fluralaner significantly reduced the site-level infestation and abundance of pyrethroid-resistant T. infestans and should be tested more widely in Phase III efficacy trials.
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Affiliation(s)
- Mariano Alberto Laiño
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Laboratory of Eco-Epidemiology, Ciudad Universitaria, Buenos Aires, Argentina
- Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina
| | - Marta Victoria Cardinal
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Laboratory of Eco-Epidemiology, Ciudad Universitaria, Buenos Aires, Argentina
- Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina
| | - María Sol Gaspe
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Laboratory of Eco-Epidemiology, Ciudad Universitaria, Buenos Aires, Argentina
- Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina
| | - Gustavo Fabián Enriquez
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Laboratory of Eco-Epidemiology, Ciudad Universitaria, Buenos Aires, Argentina
- Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina
| | - Alejandra Alvedro
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Laboratory of Eco-Epidemiology, Ciudad Universitaria, Buenos Aires, Argentina
- Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina
| | - Natalia Paula Macchiaverna
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Laboratory of Eco-Epidemiology, Ciudad Universitaria, Buenos Aires, Argentina
- Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina
| | - Ricardo E Gürtler
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Laboratory of Eco-Epidemiology, Ciudad Universitaria, Buenos Aires, Argentina
- Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina
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20
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García GA, Atkinson B, Donfack OT, Hilton ER, Smith JM, Eyono JNM, Iyanga MM, Vaz LM, Mba Nguema Avue R, Pollock J, Ratsirarson J, Aldrich EM, Phiri WP, Smith DL, Schwabe C, Guerra CA. Real-time, spatial decision support to optimize malaria vector control: The case of indoor residual spraying on Bioko Island, Equatorial Guinea. PLOS DIGITAL HEALTH 2022; 1:e0000025. [PMID: 36812503 PMCID: PMC9931250 DOI: 10.1371/journal.pdig.0000025] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 03/15/2022] [Indexed: 06/18/2023]
Abstract
Public health interventions require evidence-based decision-making to maximize impact. Spatial decision support systems (SDSS) are designed to collect, store, process and analyze data to generate knowledge and inform decisions. This paper discusses how the use of a SDSS, the Campaign Information Management System (CIMS), to support malaria control operations on Bioko Island has impacted key process indicators of indoor residual spraying (IRS): coverage, operational efficiency and productivity. We used data from the last five annual IRS rounds (2017 to 2021) to estimate these indicators. IRS coverage was calculated as the percentage of houses sprayed per unit area, represented by 100x100 m map-sectors. Optimal coverage was defined as between 80% and 85%, and under and overspraying as coverage below 80% and above 85%, respectively. Operational efficiency was defined as the fraction of map-sectors that achieved optimal coverage. Daily productivity was expressed as the number of houses sprayed per sprayer per day (h/s/d). These indicators were compared across the five rounds. Overall IRS coverage (i.e. percent of total houses sprayed against the overall denominator by round) was highest in 2017 (80.2%), yet this round showed the largest proportion of oversprayed map-sectors (36.0%). Conversely, despite producing a lower overall coverage (77.5%), the 2021 round showed the highest operational efficiency (37.7%) and the lowest proportion of oversprayed map-sectors (18.7%). In 2021, higher operational efficiency was also accompanied by marginally higher productivity. Productivity ranged from 3.3 h/s/d in 2020 to 3.9 h/s/d in 2021 (median 3.6 h/s/d). Our findings showed that the novel approach to data collection and processing proposed by the CIMS has significantly improved the operational efficiency of IRS on Bioko. High spatial granularity during planning and deployment together with closer follow-up of field teams using real-time data supported more homogeneous delivery of optimal coverage while sustaining high productivity.
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Affiliation(s)
- Guillermo A. García
- Medical Care Development International, Silver Spring, MD, United States of America
| | - Brent Atkinson
- Medical Care Development International, Silver Spring, MD, United States of America
| | | | - Emily R. Hilton
- Institute for Health Metrics and Evaluation, Univeristy of Washington, Seattle, WA, United States of America
| | - Jordan M. Smith
- Medical Care Development International, Malabo, Equatorial Guinea
| | | | | | | | | | - John Pollock
- Medical Care Development, Augusta, ME, United States of America
| | - Josea Ratsirarson
- Medical Care Development International, Silver Spring, MD, United States of America
| | | | - Wonder P. Phiri
- Medical Care Development International, Malabo, Equatorial Guinea
| | - David L. Smith
- Institute for Health Metrics and Evaluation, Univeristy of Washington, Seattle, WA, United States of America
| | | | - Carlos A. Guerra
- Medical Care Development International, Silver Spring, MD, United States of America
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21
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Keesing F, Mowry S, Bremer W, Duerr S, Evans AS, Fischhoff IR, Hinckley AF, Hook SA, Keating F, Pendleton J, Pfister A, Teator M, Ostfeld RS. Effects of Tick-Control Interventions on Tick Abundance, Human Encounters with Ticks, and Incidence of Tickborne Diseases in Residential Neighborhoods, New York, USA. Emerg Infect Dis 2022; 28:957-966. [PMID: 35447066 PMCID: PMC9045441 DOI: 10.3201/eid2805.211146] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Tickborne diseases (TBDs) such as Lyme disease result in ≈500,000 diagnoses annually in the United States. Various methods can reduce the abundance of ticks at small spatial scales, but whether these methods lower incidence of TBDs is poorly understood. We conducted a randomized, replicated, fully crossed, placebo-controlled, masked experiment to test whether 2 environmentally safe interventions, the Tick Control System (TCS) and Met52 fungal spray, used separately or together, affected risk for and incidence of TBDs in humans and pets in 24 residential neighborhoods. All participating properties in a neighborhood received the same treatment. TCS was associated with fewer questing ticks and fewer ticks feeding on rodents. The interventions did not result in a significant difference in incidence of human TBDs but did significantly reduce incidence in pets. Our study is consistent with previous evidence suggesting that reducing tick abundance in residential areas might not reduce incidence of TBDs in humans.
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22
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Collins MH, Potter GE, Hitchings MDT, Butler E, Wiles M, Kennedy JK, Pinto SB, Teixeira ABM, Casanovas-Massana A, Rouphael NG, Deye GA, Simmons CP, Moreira LA, Nogueira ML, Cummings DAT, Ko AI, Teixeira MM, Edupuganti S. EVITA Dengue: a cluster-randomized controlled trial to EValuate the efficacy of Wolbachia-InfecTed Aedes aegypti mosquitoes in reducing the incidence of Arboviral infection in Brazil. Trials 2022; 23:185. [PMID: 35236394 PMCID: PMC8889395 DOI: 10.1186/s13063-022-05997-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Accepted: 01/03/2022] [Indexed: 11/12/2022] Open
Abstract
Background Arboviruses transmitted by Aedes aegypti including dengue, Zika, and chikungunya are a major global health problem, with over 2.5 billion at risk for dengue alone. There are no licensed antivirals for these infections, and safe and effective vaccines are not yet widely available. Thus, prevention of arbovirus transmission by vector modification is a novel approach being pursued by multiple researchers. However, the field needs high-quality evidence derived from randomized, controlled trials upon which to base the implementation and maintenance of vector control programs. Here, we report the EVITA Dengue trial design (DMID 17-0111), which assesses the efficacy in decreasing arbovirus transmission of an innovative approach developed by the World Mosquito Program for vector modification of Aedes mosquitoes by Wolbachia pipientis. Methods DMID 17-0111 is a cluster-randomized trial in Belo Horizonte, Brazil, with clusters defined by primary school catchment areas. Clusters (n = 58) will be randomized 1:1 to intervention (release of Wolbachia-infected Aedes aegypti mosquitoes) vs. control (no release). Standard vector control activities (i.e., insecticides and education campaigns for reduction of mosquito breeding sites) will continue as per current practice in the municipality. Participants (n = 3480, 60 per cluster) are children aged 6–11 years enrolled in the cluster-defining school and living within the cluster boundaries who will undergo annual serologic surveillance for arboviral infection. The primary objective is to compare sero-incidence of arboviral infection between arms. Discussion DMID 17-0111 aims to determine the efficacy of Wolbachia-infected mosquito releases in reducing human infections by arboviruses transmitted by Aedes aegypti and will complement the mounting evidence for this method from large-scale field releases and ongoing trials. The trial also represents a critical step towards robustness and rigor for how vector control methods are assessed, including the simultaneous measurement and correlation of entomologic and epidemiologic outcomes. Data from this trial will inform further the development of novel vector control methods. Trial registration ClinicalTrials.govNCT04514107. Registered on 17 August 2020 Primary sponsor: National Institute of Health, National Institute of Allergy and Infectious Diseases Supplementary Information The online version contains supplementary material available at 10.1186/s13063-022-05997-4.
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Affiliation(s)
- Matthew H Collins
- Department of Medicine, Division of Infectious Diseases, The Hope Clinic of the Emory Vaccine Center, Emory University, Atlanta, GA, USA
| | - Gail E Potter
- Biostatistics Research Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA.,The Emmes Company, LLC, Rockville, USA
| | - Matt D T Hitchings
- Emerging Pathogens Institute and Department of Biology, University of Florida, Gainesville, FL, USA
| | - Ellie Butler
- Department of Medicine, Division of Infectious Diseases, The Hope Clinic of the Emory Vaccine Center, Emory University, Atlanta, GA, USA
| | - Michelle Wiles
- Department of Medicine, Division of Infectious Diseases, The Hope Clinic of the Emory Vaccine Center, Emory University, Atlanta, GA, USA
| | | | - Sofia B Pinto
- World Mosquito Program, Monash University, Melbourne, 3800, Australia
| | - Adla B M Teixeira
- School of Education, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Minas Gerais, Brazil
| | - Arnau Casanovas-Massana
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA
| | - Nadine G Rouphael
- Department of Medicine, Division of Infectious Diseases, The Hope Clinic of the Emory Vaccine Center, Emory University, Atlanta, GA, USA
| | - Gregory A Deye
- Division of Microbiology and Infectious Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, MD, USA
| | - Cameron P Simmons
- World Mosquito Program, Monash University, Melbourne, 3800, Australia
| | - Luciano A Moreira
- Instituto René Rachou, Fiocruz, Belo Horizonte, Minas Gerais, Brazil
| | - Mauricio L Nogueira
- Medical School of São Jose do Rio Preto FAMERP, São Jose do Rio Preto, São Paulo, Brazil
| | - Derek A T Cummings
- Emerging Pathogens Institute and Department of Biology, University of Florida, Gainesville, FL, USA.
| | - Albert I Ko
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA. .,Instituto Gonçalo Moniz, Fundação Oswaldo Cruz (Fiocruz), Salvador, Bahia, Brazil.
| | - Mauro M Teixeira
- Department of Biochemistry and Immunology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
| | - Srilatha Edupuganti
- Department of Medicine, Division of Infectious Diseases, The Hope Clinic of the Emory Vaccine Center, Emory University, Atlanta, GA, USA.
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23
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Review of the ecology and behaviour of Aedes aegypti and Aedes albopictus in Western Africa and implications for vector control. CURRENT RESEARCH IN PARASITOLOGY & VECTOR-BORNE DISEASES 2022; 2:100074. [PMID: 35726222 PMCID: PMC7612875 DOI: 10.1016/j.crpvbd.2021.100074] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Western Africa is vulnerable to arboviral disease transmission, having recently experienced major outbreaks of chikungunya, dengue, yellow fever and Zika. However, there have been relatively few studies on the natural history of the two major human arbovirus vectors in this region, Aedes aegypti and Ae. albopictus, potentially limiting the implementation of effective vector control. We systematically searched for and reviewed relevant studies on the behaviour and ecology of Ae. aegypti and Ae. albopictus in Western Africa, published over the last 40 years. We identified 73 relevant studies, over half of which were conducted in Nigeria, Senegal, or Côte d'Ivoire. Most studies investigated the ecology of Ae. aegypti and Ae. albopictus, exploring the impact of seasonality and land cover on mosquito populations and identifying aquatic habitats. This review highlights the adaptation of Ae. albopictus to urban environments and its invasive potential, and the year-round maintenance of Ae. aegypti populations in water storage containers. However, important gaps were identified in the literature on the behaviour of both species, particularly Ae. albopictus. In Western Africa, Ae. aegypti and Ae. albopictus appear to be mainly anthropophilic and to bite predominantly during the day, but further research is needed to confirm this to inform planning of effective vector control strategies. We discuss the public health implications of these findings and comment on the suitability of existing and novel options for control in Western Africa.
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24
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Multerer L, Vanobberghen F, Glass TR, Hiscox A, Lindsay SW, Takken W, Tiono A, Smith T. Estimating intervention effectiveness in trials of malaria interventions with contamination. Malar J 2021; 20:413. [PMID: 34670558 PMCID: PMC8527711 DOI: 10.1186/s12936-021-03924-7] [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: 12/09/2020] [Accepted: 09/21/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In cluster randomized trials (CRTs) or stepped wedge cluster randomized trials (SWCRTs) of malaria interventions, mosquito movement leads to contamination between trial arms unless buffer zones separate the clusters. Contamination can be accounted for in the analysis, yielding an estimate of the contamination range, the distance over which contamination measurably biases the effectiveness. METHODS A previously described analysis for CRTs is extended to SWCRTs and estimates of effectiveness are provided as a function of intervention coverage. The methods are applied to two SWCRTs of malaria interventions, the SolarMal trial on the impact of mass trapping of mosquitoes with odor-baited traps and the AvecNet trial on the effect of adding pyriproxyfen to long-lasting insecticidal nets. RESULTS For the SolarMal trial, the contamination range was estimated to be 146 m ([Formula: see text] credible interval [Formula: see text] km), together with a [Formula: see text] ([Formula: see text] credible interval [Formula: see text]) reduction of Plasmodium infection, compared to the [Formula: see text] reduction estimated without accounting for contamination. The estimated effectiveness had an approximately linear relationship with coverage. For the AvecNet trial, estimated contamination effects were minimal, with insufficient data from the cluster boundary regions to estimate the effectiveness as a function of coverage. CONCLUSIONS The contamination range in these trials of malaria interventions is much less than the distances Anopheles mosquitoes can fly. An appropriate analysis makes buffer zones unnecessary, enabling the design of more cost-efficient trials. Estimation of the contamination range requires information from the cluster boundary regions and trials should be designed to collect this.
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Affiliation(s)
- Lea Multerer
- Swiss Tropical and Public Health Institute, Basel, Switzerland. .,University of Basel, Basel, Switzerland.
| | - Fiona Vanobberghen
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Tracy R Glass
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Alexandra Hiscox
- Laboratory of Entomology, Wageningen University & Research, Wageningen, The Netherlands.,ARCTEC, London School of Hygiene and Tropical Medicine, London, UK
| | | | - Willem Takken
- Laboratory of Entomology, Wageningen University & Research, Wageningen, The Netherlands
| | - Alfred Tiono
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Thomas Smith
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
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25
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Lucas ER, Darby AC, Torr SJ, Donnelly MJ. A gene expression panel for estimating age in males and females of the sleeping sickness vector Glossina morsitans. PLoS Negl Trop Dis 2021; 15:e0009797. [PMID: 34555037 PMCID: PMC8491940 DOI: 10.1371/journal.pntd.0009797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 10/05/2021] [Accepted: 09/08/2021] [Indexed: 12/02/2022] Open
Abstract
Many vector-borne diseases are controlled by methods that kill the insect vectors responsible for disease transmission. Recording the age structure of vector populations provides information on mortality rates and vectorial capacity, and should form part of the detailed monitoring that occurs in the wake of control programmes, yet tools for obtaining estimates of individual age remain limited. We investigate the potential of using markers of gene expression to predict age in tsetse flies, which are the vectors of deadly and economically damaging African trypanosomiases. We use RNAseq to identify candidate expression markers, and test these markers using qPCR in laboratory-reared Glossina morsitans morsitans of known age. Measuring the expression of six genes was sufficient to obtain a prediction of age with root mean squared error of less than 8 days, while just two genes were sufficient to classify flies into age categories of ≤15 and >15 days old. Further testing of these markers in field-caught samples and in other species will determine the accuracy of these markers in the field.
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Affiliation(s)
- Eric R. Lucas
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Alistair C. Darby
- Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Stephen J. Torr
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Martin J. Donnelly
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Wellcome Sanger Institute, Cambridge, United Kingdom
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26
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Antonio-Nkondjio C, Doumbe-Belisse P, Djamouko-Djonkam L, Ngadjeu CS, Talipouo A, Kopya E, Bamou R, Mayi MPA, Sonhafouo-Chiana N, Nkahe DL, Tabue R, Fosah DA, Bigoga JD, Awono-Ambene P, Wondji CS. High efficacy of microbial larvicides for malaria vectors control in the city of Yaounde Cameroon following a cluster randomized trial. Sci Rep 2021; 11:17101. [PMID: 34429446 PMCID: PMC8385066 DOI: 10.1038/s41598-021-96362-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 08/03/2021] [Indexed: 11/12/2022] Open
Abstract
The rapid expansion of insecticide resistance and outdoor malaria transmission are affecting the efficacy of current malaria control measures. In urban settings, where malaria transmission is focal and breeding habitats are few, fixed and findable, the addition of anti-larval control measures could be efficient for malaria vector control. But field evidences for this approach remains scarce. Here we provide findings of a randomized-control larviciding trial conducted in the city of Yaoundé that support the efficacy of this approach. A two arms random control trial design including 26 clusters of 2 to 4 km2 each (13 clusters in the intervention area and 13 in the non-intervention area) was used to assess larviciding efficacy. The microbial larvicide VectoMax combining Bacillus thuringiensis var israelensis (Bti) and Bacillus sphaericus in a single granule was applied every 2 weeks in all standing water collection points. The anopheline density collected using CDC light traps was used as the primary outcome, secondary outcomes included the entomological inoculation rate, breeding habitats with anopheline larvae, and larval density. Baseline entomological data collection was conducted for 17 months from March 2017 to July 2018 and the intervention lasted 26 months from September 2018 to November 2020. The intervention was associated with a reduction of 68% of adult anopheline biting density and of 79% of the entomological inoculation rate (OR 0.21; 95% CI 0.14-0.30, P < 0.0001). A reduction of 68.27% was recorded for indoor biting anophelines and 57.74% for outdoor biting anophelines. No impact on the composition of anopheline species was recorded. A reduction of over 35% of adult Culex biting densities was recorded. The study indicated high efficacy of larviciding for reducing malaria transmission intensity in the city of Yaoundé. Larviciding could be part of an integrated control approach for controlling malaria vectors and other mosquito species in the urban environment.
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Affiliation(s)
- Christophe Antonio-Nkondjio
- Laboratoire de Recherche Sur Le Paludisme, Organisation de Coordination Pour La Lutte Contre Les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroun.
- Department of Vector Biology, Liverpool School of Tropical Medicine Pembroke Place, Liverpool, L3 5QA, UK.
| | - P Doumbe-Belisse
- Laboratoire de Recherche Sur Le Paludisme, Organisation de Coordination Pour La Lutte Contre Les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroun
- Faculty of Sciences, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - L Djamouko-Djonkam
- Laboratoire de Recherche Sur Le Paludisme, Organisation de Coordination Pour La Lutte Contre Les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroun
- Vector Borne Diseases Laboratory of the Biology and Applied Ecology Research Unit (VBID-URBEA), Department of Animal Biology, Faculty of Science of the University of Dschang, Dschang, Cameroon
| | - C S Ngadjeu
- Laboratoire de Recherche Sur Le Paludisme, Organisation de Coordination Pour La Lutte Contre Les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroun
- Faculty of Sciences, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - A Talipouo
- Laboratoire de Recherche Sur Le Paludisme, Organisation de Coordination Pour La Lutte Contre Les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroun
- Faculty of Sciences, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - E Kopya
- Laboratoire de Recherche Sur Le Paludisme, Organisation de Coordination Pour La Lutte Contre Les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroun
- Faculty of Sciences, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - R Bamou
- Laboratoire de Recherche Sur Le Paludisme, Organisation de Coordination Pour La Lutte Contre Les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroun
- Vector Borne Diseases Laboratory of the Biology and Applied Ecology Research Unit (VBID-URBEA), Department of Animal Biology, Faculty of Science of the University of Dschang, Dschang, Cameroon
| | - M P Audrey Mayi
- Vector Borne Diseases Laboratory of the Biology and Applied Ecology Research Unit (VBID-URBEA), Department of Animal Biology, Faculty of Science of the University of Dschang, Dschang, Cameroon
| | - N Sonhafouo-Chiana
- Laboratoire de Recherche Sur Le Paludisme, Organisation de Coordination Pour La Lutte Contre Les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroun
- Faculty of Sciences, University of Buea, P.O. Box 63, Buea, Cameroon
| | - D L Nkahe
- Faculty of Sciences, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon
| | - R Tabue
- Ministry of Public Health, National Malaria Control Programme, Yaoundé, Cameroon
| | - D Achu Fosah
- Ministry of Public Health, National Malaria Control Programme, Yaoundé, Cameroon
| | - Jude D Bigoga
- Laboratory for Vector Biology and Control, National Reference Unit for Vector Control, The Biotechnology Center, Nkolbisson-University of Yaounde I, P.O. Box 3851, Messa, Yaoundé, Cameroon
- Department of Biochemistry, Faculty of Science, University of Yaounde I, Yaoundé, Cameroon
| | - P Awono-Ambene
- Laboratoire de Recherche Sur Le Paludisme, Organisation de Coordination Pour La Lutte Contre Les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroun
| | - Charles S Wondji
- Department of Vector Biology, Liverpool School of Tropical Medicine Pembroke Place, Liverpool, L3 5QA, UK
- Centre for Research in Infectious Diseases, Yaoundé, Cameroon
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Jackson CL, Colborn K, Gao D, Rao S, Slater HC, Parikh S, Foy BD, Kittelson J. Design and analysis of a 2-year parallel follow-up of repeated ivermectin mass drug administrations for control of malaria: Small sample considerations for cluster-randomized trials with count data. Clin Trials 2021; 18:582-593. [PMID: 34218684 DOI: 10.1177/17407745211028581] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Cluster-randomized trials allow for the evaluation of a community-level or group-/cluster-level intervention. For studies that require a cluster-randomized trial design to evaluate cluster-level interventions aimed at controlling vector-borne diseases, it may be difficult to assess a large number of clusters while performing the additional work needed to monitor participants, vectors, and environmental factors associated with the disease. One such example of a cluster-randomized trial with few clusters was the "efficacy and risk of harms of repeated ivermectin mass drug administrations for control of malaria" trial. Although previous work has provided recommendations for analyzing trials like repeated ivermectin mass drug administrations for control of malaria, additional evaluation of the multiple approaches for analysis is needed for study designs with count outcomes. METHODS Using a simulation study, we applied three analysis frameworks to three cluster-randomized trial designs (single-year, 2-year parallel, and 2-year crossover) in the context of a 2-year parallel follow-up of repeated ivermectin mass drug administrations for control of malaria. Mixed-effects models, generalized estimating equations, and cluster-level analyses were evaluated. Additional 2-year parallel designs with different numbers of clusters and different cluster correlations were also explored. RESULTS Mixed-effects models with a small sample correction and unweighted cluster-level summaries yielded both high power and control of the Type I error rate. Generalized estimating equation approaches that utilized small sample corrections controlled the Type I error rate but did not confer greater power when compared to a mixed model approach with small sample correction. The crossover design generally yielded higher power relative to the parallel equivalent. Differences in power between analysis methods became less pronounced as the number of clusters increased. The strength of within-cluster correlation impacted the relative differences in power. CONCLUSION Regardless of study design, cluster-level analyses as well as individual-level analyses like mixed-effects models or generalized estimating equations with small sample size corrections can both provide reliable results in small cluster settings. For 2-year parallel follow-up of repeated ivermectin mass drug administrations for control of malaria, we recommend a mixed-effects model with a pseudo-likelihood approximation method and Kenward-Roger correction. Similarly designed studies with small sample sizes and count outcomes should consider adjustments for small sample sizes when using a mixed-effects model or generalized estimating equation for analysis. Although the 2-year parallel follow-up of repeated ivermectin mass drug administrations for control of malaria is already underway as a parallel trial, applying the simulation parameters to a crossover design yielded improved power, suggesting that crossover designs may be valuable in settings where the number of available clusters is limited. Finally, the sensitivity of the analysis approach to the strength of within-cluster correlation should be carefully considered when selecting the primary analysis for a cluster-randomized trial.
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Affiliation(s)
- Conner L Jackson
- Department of Biostatistics and Informatics, Colorado School of Public Health, Aurora, CO, USA.,Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Kathryn Colborn
- Department of Biostatistics and Informatics, Colorado School of Public Health, Aurora, CO, USA.,Surgical Outcomes and Applied Research Program, Department of Surgery, University of Colorado School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Dexiang Gao
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Sangeeta Rao
- Department of Clinical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Hannah C Slater
- Malaria and NTDs, PATH, Seattle, WA, USA.,MRC Centre for Global Infectious Disease Analysis, Imperial College London, London, UK
| | - Sunil Parikh
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA
| | - Brian D Foy
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, USA
| | - John Kittelson
- Department of Biostatistics and Informatics, Colorado School of Public Health, Aurora, CO, USA
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Pinto SB, Riback TIS, Sylvestre G, Costa G, Peixoto J, Dias FBS, Tanamas SK, Simmons CP, Dufault SM, Ryan PA, O’Neill SL, Muzzi FC, Kutcher S, Montgomery J, Green BR, Smithyman R, Eppinghaus A, Saraceni V, Durovni B, Anders KL, Moreira LA. Effectiveness of Wolbachia-infected mosquito deployments in reducing the incidence of dengue and other Aedes-borne diseases in Niterói, Brazil: A quasi-experimental study. PLoS Negl Trop Dis 2021; 15:e0009556. [PMID: 34252106 PMCID: PMC8297942 DOI: 10.1371/journal.pntd.0009556] [Citation(s) in RCA: 68] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 07/22/2021] [Accepted: 06/09/2021] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND The introduction of the bacterium Wolbachia (wMel strain) into Aedes aegypti mosquitoes reduces their capacity to transmit dengue and other arboviruses. Evidence of a reduction in dengue case incidence following field releases of wMel-infected Ae. aegypti has been reported previously from a cluster randomised controlled trial in Indonesia, and quasi-experimental studies in Indonesia and northern Australia. METHODOLOGY/PRINCIPAL FINDINGS Following pilot releases in 2015-2016 and a period of intensive community engagement, deployments of adult wMel-infected Ae. aegypti mosquitoes were conducted in Niterói, Brazil during 2017-2019. Deployments were phased across four release zones, with a total area of 83 km2 and a residential population of approximately 373,000. A quasi-experimental design was used to evaluate the effectiveness of wMel deployments in reducing dengue, chikungunya and Zika incidence. An untreated control zone was pre-defined, which was comparable to the intervention area in historical dengue trends. The wMel intervention effect was estimated by controlled interrupted time series analysis of monthly dengue, chikungunya and Zika case notifications to the public health surveillance system before, during and after releases, from release zones and the control zone. Three years after commencement of releases, wMel introgression into local Ae. aegypti populations was heterogeneous throughout Niterói, reaching a high prevalence (>80%) in the earliest release zone, and more moderate levels (prevalence 40-70%) elsewhere. Despite this spatial heterogeneity in entomological outcomes, the wMel intervention was associated with a 69% reduction in dengue incidence (95% confidence interval 54%, 79%), a 56% reduction in chikungunya incidence (95%CI 16%, 77%) and a 37% reduction in Zika incidence (95%CI 1%, 60%), in the aggregate release area compared with the pre-defined control area. This significant intervention effect on dengue was replicated across all four release zones, and in three of four zones for chikungunya, though not in individual release zones for Zika. CONCLUSIONS/SIGNIFICANCE We demonstrate that wMel Wolbachia can be successfully introgressed into Ae. aegypti populations in a large and complex urban setting, and that a significant public health benefit from reduced incidence of Aedes-borne disease accrues even where the prevalence of wMel in local mosquito populations is moderate and spatially heterogeneous. These findings are consistent with the results of randomised and non-randomised field trials in Indonesia and northern Australia, and are supportive of the Wolbachia biocontrol method as a multivalent intervention against dengue, chikungunya and Zika.
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Affiliation(s)
| | | | | | | | - Julia Peixoto
- World Mosquito Program, Fiocruz, Rio de Janeiro, Brazil
| | - Fernando B. S. Dias
- World Mosquito Program, Fiocruz, Rio de Janeiro, Brazil
- Gabinete da Presidência, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Stephanie K. Tanamas
- World Mosquito Program, Institute of Vector Borne Disease, Monash University, Clayton, Australia
| | - Cameron P. Simmons
- World Mosquito Program, Institute of Vector Borne Disease, Monash University, Clayton, Australia
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Suzanne M. Dufault
- Division of Biostatistics, School of Public Health, University of California, Berkeley, California, United States of America
| | - Peter A. Ryan
- World Mosquito Program, Institute of Vector Borne Disease, Monash University, Clayton, Australia
| | - Scott L. O’Neill
- World Mosquito Program, Institute of Vector Borne Disease, Monash University, Clayton, Australia
| | - Frederico C. Muzzi
- World Mosquito Program, Institute of Vector Borne Disease, Monash University, Clayton, Australia
| | - Simon Kutcher
- World Mosquito Program, Institute of Vector Borne Disease, Monash University, Clayton, Australia
| | - Jacqui Montgomery
- World Mosquito Program, Institute of Vector Borne Disease, Monash University, Clayton, Australia
| | - Benjamin R. Green
- World Mosquito Program, Institute of Vector Borne Disease, Monash University, Clayton, Australia
| | - Ruth Smithyman
- World Mosquito Program, Institute of Vector Borne Disease, Monash University, Clayton, Australia
| | | | | | - Betina Durovni
- World Mosquito Program, Fiocruz, Rio de Janeiro, Brazil
- Centre for Strategic Studies, Fiocruz, Rio de Janeiro, Brazil
| | - Katherine L. Anders
- World Mosquito Program, Institute of Vector Borne Disease, Monash University, Clayton, Australia
| | - Luciano A. Moreira
- World Mosquito Program, Fiocruz, Rio de Janeiro, Brazil
- Instituto Rene Rachou, Fiocruz, Belo Horizonte, Brazil
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29
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Cardinal MV, Enriquez GF, Macchiaverna NP, Argibay HD, Fernández MDP, Alvedro A, Gaspe MS, Gürtler RE. Long-term impact of a ten-year intervention program on human and canine Trypanosoma cruzi infection in the Argentine Chaco. PLoS Negl Trop Dis 2021; 15:e0009389. [PMID: 33979344 PMCID: PMC8115854 DOI: 10.1371/journal.pntd.0009389] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 04/13/2021] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Interruption of domestic vector-borne transmission of Trypanosoma cruzi is still an unmet goal in several American countries. In 2007 we launched a long-term intervention program aimed to suppress house infestation with the main domestic vector in southern South America (Triatoma infestans) and domestic transmission in Pampa del Indio, a resource-constrained, hyperendemic municipality with 1446 rural houses inhabited by Creole and indigenous people, in the Argentine Chaco ecoregion. Here, we assessed whether the 10-year insecticide-based program combined with community mobilization blocked vector-borne domestic transmission of T. cruzi to humans and dogs. METHODS We carried out two municipality-wide, cross-sectional serosurveys of humans and dogs (considered sentinel animals) during 2016-2017 to compare with baseline data. We used a risk-stratified random sampling design to select 273 study houses; 410 people from 180 households and 492 dogs from 151 houses were examined for antibodies to T. cruzi using at least two serological methods. RESULTS The seroprevalence of T. cruzi in children aged <16 years was 2.5% in 2017 (i.e., 4- to 11-fold lower than before interventions). The mean annual force of child infection (λ) sharply decreased from 2.18 to 0.34 per 100 person-years in 2017. One of 102 children born after interventions was seropositive for T. cruzi; he had lifetime residence in an apparently uninfested house, no outside travel history, and his mother was T. cruzi-seropositive. No incident case was detected among 114 seronegative people of all ages re-examined serologically. Dog seroprevalence was 3.05%. Among native dogs, λ in 2016 (1.21 per 100 dog-years) was 5 times lower than at program onset. Six native adult dogs born after interventions and with stable lifetime residence were T. cruzi-seropositive: three had exposure to T. infestans at their houses and one was an incident case. CONCLUSIONS These results support the interruption of vector-borne transmission of T. cruzi to humans in rural Pampa del Indio. Congenital transmission was the most likely source of the only seropositive child born after interventions. Residual transmission to dogs was likely related to transient infestations and other transmission routes. Sustained vector control supplemented with human chemotherapy can lead to a substantial reduction of Chagas disease transmission in the Argentine Chaco.
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Affiliation(s)
- Marta Victoria Cardinal
- Laboratorio de Eco-Epidemiología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- CONICET-Universidad de Buenos Aires, Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Buenos Aires, Argentina
- * E-mail:
| | - Gustavo Fabián Enriquez
- Laboratorio de Eco-Epidemiología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- CONICET-Universidad de Buenos Aires, Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Buenos Aires, Argentina
| | - Natalia Paula Macchiaverna
- Laboratorio de Eco-Epidemiología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- CONICET-Universidad de Buenos Aires, Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Buenos Aires, Argentina
| | - Hernán Darío Argibay
- Laboratorio de Eco-Epidemiología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- CONICET-Universidad de Buenos Aires, Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Buenos Aires, Argentina
| | - María del Pilar Fernández
- Laboratorio de Eco-Epidemiología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- CONICET-Universidad de Buenos Aires, Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Buenos Aires, Argentina
- Paul G. Allen School for Global Health, Washington State University, Pullman, Washington, United States for America
| | - Alejandra Alvedro
- Laboratorio de Eco-Epidemiología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- CONICET-Universidad de Buenos Aires, Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Buenos Aires, Argentina
| | - María Sol Gaspe
- Laboratorio de Eco-Epidemiología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- CONICET-Universidad de Buenos Aires, Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Buenos Aires, Argentina
| | - Ricardo Esteban Gürtler
- Laboratorio de Eco-Epidemiología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- CONICET-Universidad de Buenos Aires, Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Buenos Aires, Argentina
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Mwandigha LM, Fraser KJ, Racine-Poon A, Mouksassi MS, Ghani AC. Power calculations for cluster randomized trials (CRTs) with right-truncated Poisson-distributed outcomes: a motivating example from a malaria vector control trial. Int J Epidemiol 2021; 49:954-962. [PMID: 32011684 PMCID: PMC7394957 DOI: 10.1093/ije/dyz277] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 12/13/2019] [Accepted: 12/18/2019] [Indexed: 11/14/2022] Open
Abstract
Background Cluster randomized trials (CRTs) are increasingly used to study the efficacy of interventions targeted at the population level. Formulae exist to calculate sample sizes for CRTs, but they assume that the domain of the outcomes being considered covers the full range of values of the considered distribution. This assumption is frequently incorrect in epidemiological trials in which counts of infection episodes are right-truncated due to practical constraints on the number of times a person can be tested. Methods Motivated by a malaria vector control trial with right-truncated Poisson-distributed outcomes, we investigated the effect of right-truncation on power using Monte Carlo simulations. Results The results demonstrate that the adverse impact of right-truncation is directly proportional to the magnitude of the event rate, λ, with calculations of power being overestimated in instances where right-truncation was not accounted for. The severity of the adverse impact of right-truncation on power was more pronounced when the number of clusters was ≤30 but decreased the further the right-truncation point was from zero. Conclusions Potential right-truncation should always be accounted for in the calculation of sample size requirements at the study design stage.
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Affiliation(s)
- Lazaro M Mwandigha
- Department of Infectious Disease Epidemiology, MRC Centre for Global Infectious Disease Analysis, Imperial College London, London, UK
| | - Keith J Fraser
- Department of Infectious Disease Epidemiology, MRC Centre for Global Infectious Disease Analysis, Imperial College London, London, UK
| | - Amy Racine-Poon
- Department of Statistical Methodology and Consulting, Novartis Pharma AG, Basel, Switzerland.,Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - Mohamad-Samer Mouksassi
- Bill & Melinda Gates Foundation, Seattle, WA, USA.,Department of Strategic Consulting Integrated Drug Development, Certara, Montreal, QC, Canada.,School of Pharmacy, Department of Pharmaceutical Sciences, Lebanese American University, Byblos, Lebanon.,Faculty of Pharmacy, Department of Pharmaceutical Sciences, University of Montreal, Montreal, QC, Canada
| | - Azra C Ghani
- Department of Infectious Disease Epidemiology, MRC Centre for Global Infectious Disease Analysis, Imperial College London, London, UK
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Jones RT, Pretorius E, Ant TH, Bradley J, Last A, Logan JG. The use of islands and cluster-randomized trials to investigate vector control interventions: a case study on the Bijagós archipelago, Guinea-Bissau. Philos Trans R Soc Lond B Biol Sci 2021; 376:20190807. [PMID: 33357055 PMCID: PMC7776941 DOI: 10.1098/rstb.2019.0807] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/01/2020] [Indexed: 12/30/2022] Open
Abstract
Vector-borne diseases threaten the health of populations around the world. While key interventions continue to provide protection from vectors, there remains a need to develop and test new vector control tools. Cluster-randomized trials, in which the intervention or control is randomly allocated to clusters, are commonly selected for such evaluations, but their design must carefully consider cluster size and cluster separation, as well as the movement of people and vectors, to ensure sufficient statistical power and avoid contamination of results. Island settings present an opportunity to conduct these studies. Here, we explore the benefits and challenges of conducting intervention studies on islands and introduce the Bijagós archipelago of Guinea-Bissau as a potential study site for interventions intended to control vector-borne diseases. This article is part of the theme issue 'Novel control strategies for mosquito-borne diseases'.
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Affiliation(s)
- Robert T. Jones
- Department of Disease Control, London School of Hygiene & Tropical Medicine, Keppel Street, Bloomsbury, London WC1E 7HT, UK
- ARCTEC, London School of Hygiene & Tropical Medicine, Keppel Street, Bloomsbury, London WC1E 7HT, UK
| | - Elizabeth Pretorius
- Department of Disease Control, London School of Hygiene & Tropical Medicine, Keppel Street, Bloomsbury, London WC1E 7HT, UK
| | - Thomas H. Ant
- Centre for Virus Research, Bearsden Road, Bearsden, Glasgow G61 1QH, UK
| | - John Bradley
- MRC International Statistics and Epidemiology Group, London School of Hygiene & Tropical Medicine, Keppel Street, Bloomsbury, London WC1E 7HT, UK
| | - Anna Last
- Department of Clinical Research, London School of Hygiene & Tropical Medicine, Keppel Street, Bloomsbury, London WC1E 7HT, UK
| | - James G. Logan
- Department of Disease Control, London School of Hygiene & Tropical Medicine, Keppel Street, Bloomsbury, London WC1E 7HT, UK
- ARCTEC, London School of Hygiene & Tropical Medicine, Keppel Street, Bloomsbury, London WC1E 7HT, UK
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Control of ixodid ticks and prevention of tick-borne diseases in the United States: The prospect of a new Lyme disease vaccine and the continuing problem with tick exposure on residential properties. Ticks Tick Borne Dis 2021; 12:101649. [PMID: 33549976 DOI: 10.1016/j.ttbdis.2021.101649] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 12/13/2020] [Accepted: 12/29/2020] [Indexed: 01/09/2023]
Abstract
In the United States, exposure to human-biting ixodid ticks can occur while spending time on residential properties or in neighborhood green spaces as well as during recreational or occupational activities on public lands. Human-biting tick species collectively transmit >15 species of pathogenic microorganisms and the national burden of tick-borne diseases is increasing. The prospect of a new Lyme disease vaccine for use in humans provides hope for substantial reduction in the >450,000 estimated annual cases of Lyme disease but this breakthrough would not reduce cases of other tick-borne diseases, such as anaplasmosis, babesiosis, ehrlichiosis, spotted fever group rickettsiosis, and Powassan encephalitis. One intriguing question is to what extent a new Lyme disease vaccine would impact the use of personal protection measures acting broadly against tick-bites. The main tick vector for Lyme disease spirochetes in the eastern United States, Ixodes scapularis, also transmits causative agents of anaplasmosis, babesiosis, and Powassan encephalitis; and this tick species co-occurs with other human-biting vectors such as Amblyomma americanum and Dermacentor variabilis. It therefore is important that a new Lyme disease vaccine does not result in reduced use of tick-bite prevention measures, such as tick repellents, permethrin-treated clothing, and frequent tick checks. Another key issue is the continuing problem with tick exposure on residential properties, which represents a heavily used outdoor environment the residents cannot reasonably avoid and where they tend to spend large amounts of time outside. As it may not be realistic to keep up daily vigilance with personal protective measures against tick-bites on residential properties during many months of every year, homeowners may also consider the option to suppress host-seeking ticks by means of deer fencing, landscaping, vegetation management, and use of products to kill host-seeking ticks or ticks infesting rodents. When considering the full range of options for actions that can be taken to suppress host-seeking ticks on residential properties, it is clear that individual homeowners face a difficult and bewildering task in deciding what to do based on very general guidance from public health agencies (developed without the benefit of a strong evidence base) and often without ready access to local public health professionals experienced in tick control. This situation is not satisfactory but cannot be corrected without first addressing knowledge gaps regarding the impact of peridomestic tick control measures on host-seeking ticks, human tick-bites, and tick-borne diseases. In parallel with this effort, there also is a need to increase the local public health workforce with knowledge of and experience with tick control to provide better access for homeowners to sound and objective advice regarding tick control on their properties based on key characteristics of the landscaping, habitat composition, and use patterns by wild animal tick hosts as well as the residents.
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Lindsay SW, Davies M, Alabaster G, Altamirano H, Jatta E, Jawara M, Carrasco-Tenezaca M, von Seidlein L, Shenton FC, Tusting LS, Wilson AL, Knudsen J. Recommendations for building out mosquito-transmitted diseases in sub-Saharan Africa: the DELIVER mnemonic. Philos Trans R Soc Lond B Biol Sci 2020; 376:20190814. [PMID: 33357059 DOI: 10.1098/rstb.2019.0814] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
In sub-Saharan Africa, most transmission of mosquito-transmitted diseases, such as malaria or dengue, occurs within or around houses. Preventing mosquito house entry and reducing mosquito production around the home would help reduce the transmission of these diseases. Based on recent research, we make key recommendations for reducing the threat of mosquito-transmitted diseases through changes to the built environment. The mnemonic, DELIVER, recommends the following best practices: (i) Doors should be screened, self-closing and without surrounding gaps; (ii) Eaves, the space between the wall and roof, should be closed or screened; (iii) houses should be Lifted above the ground; (iv) Insecticide-treated nets should be used when sleeping in houses at night; (v) houses should be Ventilated, with at least two large-screened windows to facilitate airflow; (vi) Environmental management should be conducted regularly inside and around the home; and (vii) Roofs should be solid, rather than thatch. DELIVER is a package of interventions to be used in combination for maximum impact. Simple changes to the built environment will reduce exposure to mosquito-transmitted diseases and help keep regions free from these diseases after elimination. This article is part of the theme issue 'Novel control strategies for mosquito-borne diseases'.
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Affiliation(s)
- Steven W Lindsay
- Department of Biosciences, Durham University, Durham DH1 3LE, UK
| | - Michael Davies
- Bartlett School Environment, Energy & Resources, Faculty of the Built Environment, University College London, London WC1H 0NN, UK
| | | | - Hector Altamirano
- Bartlett School Environment, Energy & Resources, Faculty of the Built Environment, University College London, London WC1H 0NN, UK
| | - Ebrima Jatta
- National Malaria Control Programme, Banjul, The Gambia
| | - Musa Jawara
- Medical Research Council Unit Gambia at the London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | | | - Lorenz von Seidlein
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Fiona C Shenton
- Department of Biosciences, Durham University, Durham DH1 3LE, UK
| | - Lucy S Tusting
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
| | - Anne L Wilson
- Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
| | - Jakob Knudsen
- The Royal Danish Academy of Fine Arts, School of Architecture, Design and Conservation, The School of Architecture, Copenhagen, Denmark
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Manrique-Saide P, Dean NE, Halloran ME, Longini IM, Collins MH, Waller LA, Gomez-Dantes H, Lenhart A, Hladish TJ, Che-Mendoza A, Kirstein OD, Romer Y, Correa-Morales F, Palacio-Vargas J, Mendez-Vales R, Pérez PG, Pavia-Ruz N, Ayora-Talavera G, Vazquez-Prokopec GM. The TIRS trial: protocol for a cluster randomized controlled trial assessing the efficacy of preventive targeted indoor residual spraying to reduce Aedes-borne viral illnesses in Merida, Mexico. Trials 2020; 21:839. [PMID: 33032661 PMCID: PMC7542575 DOI: 10.1186/s13063-020-04780-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 09/29/2020] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Current urban vector control strategies have failed to contain dengue epidemics and to prevent the global expansion of Aedes-borne viruses (ABVs: dengue, chikungunya, Zika). Part of the challenge in sustaining effective ABV control emerges from the paucity of evidence regarding the epidemiological impact of any Aedes control method. A strategy for which there is limited epidemiological evidence is targeted indoor residual spraying (TIRS). TIRS is a modification of classic malaria indoor residual spraying that accounts for Aedes aegypti resting behavior by applying residual insecticides on exposed lower sections of walls (< 1.5 m), under furniture, and on dark surfaces. METHODS/DESIGN We are pursuing a two-arm, parallel, unblinded, cluster randomized controlled trial to quantify the overall efficacy of TIRS in reducing the burden of laboratory-confirmed ABV clinical disease (primary endpoint). The trial will be conducted in the city of Merida, Yucatan State, Mexico (population ~ 1million), where we will prospectively follow 4600 children aged 2-15 years at enrollment, distributed in 50 clusters of 5 × 5 city blocks each. Clusters will be randomly allocated (n = 25 per arm) using covariate-constrained randomization. A "fried egg" design will be followed, in which all blocks of the 5 × 5 cluster receive the intervention, but all sampling to evaluate the epidemiological and entomological endpoints will occur in the "yolk," the center 3 × 3 city blocks of each cluster. TIRS will be implemented as a preventive application (~ 1-2 months prior to the beginning of the ABV season). Active monitoring for symptomatic ABV illness will occur through weekly household visits and enhanced surveillance. Annual sero-surveys will be performed after each transmission season and entomological evaluations of Ae. aegypti indoor abundance and ABV infection rates monthly during the period of active surveillance. Epidemiological and entomological evaluation will continue for up to three transmission seasons. DISCUSSION The findings from this study will provide robust epidemiological evidence of the efficacy of TIRS in reducing ABV illness and infection. If efficacious, TIRS could drive a paradigm shift in Aedes control by considering Ae. aegypti behavior to guide residual insecticide applications and changing deployment to preemptive control (rather than in response to symptomatic cases), two major enhancements to existing practice. TRIAL REGISTRATION ClinicalTrials.gov NCT04343521 . Registered on 13 April 2020. The protocol also complies with the WHO International Clinical Trials Registry Platform (ICTRP) (Additional file 1). PRIMARY SPONSOR National Institutes of Health, National Institute of Allergy and Infectious Diseases (NIH/NIAID).
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Affiliation(s)
- Pablo Manrique-Saide
- Unidad Colaborativa de Bioensayos Entomológicos, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Merida, Mexico
| | - Natalie E Dean
- Department of Biostatistics, University of Florida, Gainesville, FL, 32611, USA
| | - M Elizabeth Halloran
- Center for Inference and Dynamics of Infectious Diseases, Seattle, WA, 98109, USA
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, 98109, USA
- Department of Biostatistics, University of Washington, Seattle, WA, 98109, USA
| | - Ira M Longini
- Department of Biostatistics, University of Florida, Gainesville, FL, 32611, USA
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, 32611, USA
| | - Matthew H Collins
- Hope Clinic of the Emory Vaccine Center, Division of Infectious Diseases, Department of Medicine, School of Medicine, Emory University, Decatur, GA, 30030, USA
| | - Lance A Waller
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, GA, 30322, USA
| | - Hector Gomez-Dantes
- Health Systems Research Center, National Institute of Public Health, Cuernavaca, Mexico
| | - Audrey Lenhart
- Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Thomas J Hladish
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, 32611, USA
- Department of Biology, University of Florida, Gainesville, FL, 32611, USA
| | - Azael Che-Mendoza
- Unidad Colaborativa de Bioensayos Entomológicos, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Merida, Mexico
| | - Oscar D Kirstein
- Department of Environmental Sciences, Math and Science Center, Emory University, 400 Dowman Drive, 5th floor, Suite E530, Atlanta, GA, 30322, USA
| | - Yamila Romer
- Department of Environmental Sciences, Math and Science Center, Emory University, 400 Dowman Drive, 5th floor, Suite E530, Atlanta, GA, 30322, USA
| | - Fabian Correa-Morales
- Centro Nacional de Programas Preventivos y Control de Enfermedades (CENAPRECE) Secretaría de Salud Mexico, Mexico City, Mexico
| | | | | | | | - Norma Pavia-Ruz
- Centro de Investigaciones Regionales Hideyo Noguchi, Universidad Autonoma de Yucatan, Merida, Mexico
| | - Guadalupe Ayora-Talavera
- Centro de Investigaciones Regionales Hideyo Noguchi, Universidad Autonoma de Yucatan, Merida, Mexico
| | - Gonzalo M Vazquez-Prokopec
- Department of Environmental Sciences, Math and Science Center, Emory University, 400 Dowman Drive, 5th floor, Suite E530, Atlanta, GA, 30322, USA.
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Zinszer K, Charland K, Vahey S, Jahagirdar D, Rek JC, Arinaitwe E, Nankabirwa J, Morrison K, Sadoine ML, Tutt-Guérette MA, Staedke SG, Kamya MR, Greenhouse B, Rodriguez-Barraquer I, Dorsey G. The Impact of Multiple Rounds of Indoor Residual Spraying on Malaria Incidence and Hemoglobin Levels in a High-Transmission Setting. J Infect Dis 2020; 221:304-312. [PMID: 31599325 DOI: 10.1093/infdis/jiz453] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 09/04/2019] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Indoor residual spraying (IRS) is widely used as a vector control measure, although there are conflicting findings of its effectiveness in reducing malaria incidence. The objective of this study was to estimate the effect of multiple IRS rounds on malaria incidence and hemoglobin levels in a cohort of children in rural southeastern Uganda. METHODS The study was based upon a dynamic cohort of children aged 0.5-10 years enrolled from August 2011 to June 2017 in Nagongera Subcounty. Confirmed malaria infections and hemoglobin levels were recorded over time for each participant. After each of 4 rounds of IRS, malaria incidence, hemoglobin levels, and parasite density were evaluated and compared with pre-IRS levels. Analyses were carried out at the participant level while accounting for repeated measures and clustering by household. RESULTS Incidence rate ratios comparing post-IRS to pre-IRS incidence rates for age groups 0-3, 3-5, and 5-11 were 0.108 (95% confidence interval [CI], .078-.149), 0.173 (95% CI, .136-.222), and 0.226 (95% CI, .187-.274), respectively. The mean hemoglobin levels significantly increased from 11.01 (pre-IRS) to 12.18 g/dL (post-IRS). CONCLUSIONS Our study supports the policy recommendation of IRS usage in a stable and perennial transmission area to rapidly reduce malaria transmission.
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Affiliation(s)
- Kate Zinszer
- Department of Social and Preventive Medicine, University of Montreal, Montreal, Quebec, Canada.,Centre de recherche en santé publique, University of Montreal, Montreal, Quebec, Canada
| | - Katia Charland
- Department of Social and Preventive Medicine, University of Montreal, Montreal, Quebec, Canada
| | - Sarah Vahey
- Centre de recherche en santé publique, University of Montreal, Montreal, Quebec, Canada
| | - Deepa Jahagirdar
- Institute for Health Metrics and Evaluation, Seattle, Washington, USA
| | - John C Rek
- Infectious Disease Research Collaboration, Makerere University, Kampala, Uganda
| | - Emmanuel Arinaitwe
- Infectious Disease Research Collaboration, Makerere University, Kampala, Uganda
| | - Joaniter Nankabirwa
- Infectious Disease Research Collaboration, Makerere University, Kampala, Uganda
| | | | - Margaux L Sadoine
- Department of Social and Preventive Medicine, University of Montreal, Montreal, Quebec, Canada.,Centre de recherche en santé publique, University of Montreal, Montreal, Quebec, Canada
| | - Marc-Antoine Tutt-Guérette
- Department of Social and Preventive Medicine, University of Montreal, Montreal, Quebec, Canada.,Centre de recherche en santé publique, University of Montreal, Montreal, Quebec, Canada
| | - Sarah G Staedke
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Moses R Kamya
- Infectious Disease Research Collaboration, Makerere University, Kampala, Uganda.,Department of Medicine, Makerere University College of Health Sciences, Kampala, Uganda
| | - Bryan Greenhouse
- Department of Medicine, University of California San Francisco, San Francisco, California, USA
| | | | - Grant Dorsey
- Department of Medicine, University of California San Francisco, San Francisco, California, USA
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Chan EYY, Sham TST, Shahzada TS, Dubois C, Huang Z, Liu S, Hung KK, Tse SL, Kwok KO, Chung PH, Kayano R, Shaw R. Narrative Review on Health-EDRM Primary Prevention Measures for Vector-Borne Diseases. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:E5981. [PMID: 32824754 PMCID: PMC7459832 DOI: 10.3390/ijerph17165981] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 08/13/2020] [Accepted: 08/13/2020] [Indexed: 01/01/2023]
Abstract
Climate change is expanding the global at-risk population for vector-borne diseases (VBDs). The World Health Organization (WHO) health emergency and disaster risk management (health-EDRM) framework emphasises the importance of primary prevention of biological hazards and its value in protecting against VBDs. The framework encourages stakeholder coordination and information sharing, though there is still a need to reinforce prevention and recovery within disaster management. This keyword-search based narrative literature review searched databases PubMed, Google Scholar, Embase and Medline between January 2000 and May 2020, and identified 134 publications. In total, 10 health-EDRM primary prevention measures are summarised at three levels (personal, environmental and household). Enabling factor, limiting factors, co-benefits and strength of evidence were identified. Current studies on primary prevention measures for VBDs focus on health risk-reduction, with minimal evaluation of actual disease reduction. Although prevention against mosquito-borne diseases, notably malaria, has been well-studied, research on other vectors and VBDs remains limited. Other gaps included the limited evidence pertaining to prevention in resource-poor settings and the efficacy of alternatives, discrepancies amongst agencies' recommendations, and limited studies on the impact of technological advancements and habitat change on VBD prevalence. Health-EDRM primary prevention measures for VBDs require high-priority research to facilitate multifaceted, multi-sectoral, coordinated responses that will enable effective risk mitigation.
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Affiliation(s)
- Emily Ying Yang Chan
- Collaborating Centre for Oxford University and CUHK for Disaster and Medical Humanitarian Response (CCOUC), The Chinese University of Hong Kong, Hong Kong SAR, China; (Z.H.); (S.L.); (K.K.C.H.)
- Nuffield Department of Medicine, University of Oxford, Oxford OX37BN, UK
- JC School of Public Health and Primary Care, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China; (T.S.T.S.); (T.S.S.); (S.L.A.T.); (K.O.K.); (P.-H.C.)
- GX Foundation, Hong Kong SAR, China;
- Accident & Emergency Medicine Academic Unit, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong SAR, China
| | - Tiffany Sze Tung Sham
- JC School of Public Health and Primary Care, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China; (T.S.T.S.); (T.S.S.); (S.L.A.T.); (K.O.K.); (P.-H.C.)
- GX Foundation, Hong Kong SAR, China;
| | - Tayyab Salim Shahzada
- JC School of Public Health and Primary Care, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China; (T.S.T.S.); (T.S.S.); (S.L.A.T.); (K.O.K.); (P.-H.C.)
- GX Foundation, Hong Kong SAR, China;
| | | | - Zhe Huang
- Collaborating Centre for Oxford University and CUHK for Disaster and Medical Humanitarian Response (CCOUC), The Chinese University of Hong Kong, Hong Kong SAR, China; (Z.H.); (S.L.); (K.K.C.H.)
- JC School of Public Health and Primary Care, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China; (T.S.T.S.); (T.S.S.); (S.L.A.T.); (K.O.K.); (P.-H.C.)
| | - Sida Liu
- Collaborating Centre for Oxford University and CUHK for Disaster and Medical Humanitarian Response (CCOUC), The Chinese University of Hong Kong, Hong Kong SAR, China; (Z.H.); (S.L.); (K.K.C.H.)
- GX Foundation, Hong Kong SAR, China;
| | - Kevin K.C. Hung
- Collaborating Centre for Oxford University and CUHK for Disaster and Medical Humanitarian Response (CCOUC), The Chinese University of Hong Kong, Hong Kong SAR, China; (Z.H.); (S.L.); (K.K.C.H.)
- JC School of Public Health and Primary Care, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China; (T.S.T.S.); (T.S.S.); (S.L.A.T.); (K.O.K.); (P.-H.C.)
- Accident & Emergency Medicine Academic Unit, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong SAR, China
| | - Shelly L.A. Tse
- JC School of Public Health and Primary Care, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China; (T.S.T.S.); (T.S.S.); (S.L.A.T.); (K.O.K.); (P.-H.C.)
| | - Kin On Kwok
- JC School of Public Health and Primary Care, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China; (T.S.T.S.); (T.S.S.); (S.L.A.T.); (K.O.K.); (P.-H.C.)
| | - Pui-Hong Chung
- JC School of Public Health and Primary Care, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China; (T.S.T.S.); (T.S.S.); (S.L.A.T.); (K.O.K.); (P.-H.C.)
| | - Ryoma Kayano
- World Health Organization Centre for Health Development, Kobe 651-0073, Japan;
| | - Rajib Shaw
- Graduate School of Media and Governance, Keio University, Fujisawa 252-0882, Japan;
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Garcia KKS, Versiani HS, Araújo TO, Conceição JPA, Obara MT, Ramalho WM, Minuzzi-Souza TTC, Gomes GD, Vianna EN, Timbó RV, Barbosa VGC, Rezende MSP, Martins LPF, Macedo GO, Carvalho BL, Moreira IM, Bartasson LA, Nitz N, Luz SLB, Gurgel-Gonçalves R, Abad-Franch F. Measuring mosquito control: adult-mosquito catches vs egg-trap data as endpoints of a cluster-randomized controlled trial of mosquito-disseminated pyriproxyfen. Parasit Vectors 2020; 13:352. [PMID: 32665032 PMCID: PMC7362459 DOI: 10.1186/s13071-020-04221-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 07/08/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Aedes aegypti and Culex quinquefasciatus are the main urban vectors of arthropod-borne viruses causing human disease, including dengue, Zika, or West Nile. Although key to disease prevention, urban-mosquito control has met only limited success. Alternative vector-control tactics are therefore being developed and tested, often using entomological endpoints to measure impact. Here, we test one promising alternative and assess how three such endpoints perform at measuring its effects. METHODS We conducted a 16-month, two-arm, cluster-randomized controlled trial (CRCT) of mosquito-disseminated pyriproxyfen (MD-PPF) in central-western Brazil. We used three entomological endpoints: adult-mosquito density as directly measured by active aspiration of adult mosquitoes, and egg-trap-based indices of female Aedes presence (proportion of positive egg-traps) and possibly abundance (number of eggs per egg-trap). Using generalized linear mixed models, we estimated MD-PPF effects on these endpoints while accounting for the non-independence of repeated observations and for intervention-unrelated sources of spatial-temporal variation. RESULTS On average, MD-PPF reduced adult-mosquito density by 66.3% (95% confidence interval, 95% CI: 47.3-78.4%); Cx. quinquefasciatus density fell by 55.5% (95% CI: 21.1-74.8%), and Ae. aegypti density by 60.0% (95% CI: 28.7-77.5%). In contrast, MD-PPF had no measurable effect on either Aedes egg counts or egg-trap positivity, both of which decreased somewhat in the intervention cluster but also in the control cluster. Egg-trap data, therefore, failed to reflect the 60.0% mean reduction of adult Aedes density associated with MD-PPF deployment. CONCLUSIONS Our results suggest that the widely used egg-trap-based monitoring may poorly measure the impact of Aedes control; even if more costly, direct monitoring of the adult mosquito population is likely to provide a much more realistic and informative picture of intervention effects. In our CRCT, MD-PPF reduced adult-mosquito density by 66.3% in a medium-sized, spatially non-isolated, tropical urban neighborhood. Broader-scale trials will be necessary to measure MD-PPF impact on arboviral-disease transmission.
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Affiliation(s)
- Klauss K. S. Garcia
- Núcleo de Medicina Tropical, Faculdade de Medicina, Universidade de Brasília, Brasilia, Brazil
- Secretaria de Vigilância em Saúde, Ministério da Saúde, Brasilia, Brazil
| | - Hanid S. Versiani
- Laboratório de Parasitologia Médica e Biologia de Vetores, Faculdade de Medicina, Universidade de Brasília, Brasilia, Brazil
- Laboratório Interdisciplinar de Biociências, Faculdade de Medicina, Universidade de Brasília, Brasilia, Brazil
| | - Taís O. Araújo
- Laboratório de Parasitologia Médica e Biologia de Vetores, Faculdade de Medicina, Universidade de Brasília, Brasilia, Brazil
| | - João P. A. Conceição
- Núcleo de Medicina Tropical, Faculdade de Medicina, Universidade de Brasília, Brasilia, Brazil
- Laboratório de Parasitologia Médica e Biologia de Vetores, Faculdade de Medicina, Universidade de Brasília, Brasilia, Brazil
| | - Marcos T. Obara
- Núcleo de Medicina Tropical, Faculdade de Medicina, Universidade de Brasília, Brasilia, Brazil
- Laboratório de Parasitologia Médica e Biologia de Vetores, Faculdade de Medicina, Universidade de Brasília, Brasilia, Brazil
| | - Walter M. Ramalho
- Núcleo de Medicina Tropical, Faculdade de Medicina, Universidade de Brasília, Brasilia, Brazil
| | - Thaís T. C. Minuzzi-Souza
- Secretaria de Vigilância em Saúde, Ministério da Saúde, Brasilia, Brazil
- Laboratório de Parasitologia Médica e Biologia de Vetores, Faculdade de Medicina, Universidade de Brasília, Brasilia, Brazil
| | - Gustavo D. Gomes
- Laboratório de Parasitologia Médica e Biologia de Vetores, Faculdade de Medicina, Universidade de Brasília, Brasilia, Brazil
| | - Elisa N. Vianna
- Secretaria de Vigilância em Saúde, Ministério da Saúde, Brasilia, Brazil
- Laboratório de Parasitologia Médica e Biologia de Vetores, Faculdade de Medicina, Universidade de Brasília, Brasilia, Brazil
| | - Renata V. Timbó
- Laboratório de Parasitologia Médica e Biologia de Vetores, Faculdade de Medicina, Universidade de Brasília, Brasilia, Brazil
| | - Vinicios G. C. Barbosa
- Laboratório de Parasitologia Médica e Biologia de Vetores, Faculdade de Medicina, Universidade de Brasília, Brasilia, Brazil
| | - Maridalva S. P. Rezende
- Laboratório de Parasitologia Médica e Biologia de Vetores, Faculdade de Medicina, Universidade de Brasília, Brasilia, Brazil
| | - Luciana P. F. Martins
- Laboratório de Parasitologia Médica e Biologia de Vetores, Faculdade de Medicina, Universidade de Brasília, Brasilia, Brazil
| | - Glauco O. Macedo
- Laboratório de Parasitologia Médica e Biologia de Vetores, Faculdade de Medicina, Universidade de Brasília, Brasilia, Brazil
| | - Bruno L. Carvalho
- Núcleo de Medicina Tropical, Faculdade de Medicina, Universidade de Brasília, Brasilia, Brazil
| | - Israel M. Moreira
- Diretoria de Vigilância Ambiental em Saúde, Subsecretaria de Vigilância à Saúde, Secretaria de Estado de Saúde do Distrito Federal, Brasilia, Brazil
| | - Lorrainy A. Bartasson
- Diretoria de Vigilância Ambiental em Saúde, Subsecretaria de Vigilância à Saúde, Secretaria de Estado de Saúde do Distrito Federal, Brasilia, Brazil
| | - Nadjar Nitz
- Laboratório de Parasitologia Médica e Biologia de Vetores, Faculdade de Medicina, Universidade de Brasília, Brasilia, Brazil
- Laboratório Interdisciplinar de Biociências, Faculdade de Medicina, Universidade de Brasília, Brasilia, Brazil
| | - Sérgio L. B. Luz
- Instituto Leônidas e Maria Deane–Fiocruz Amazônia, Manaus, Brazil
| | - Rodrigo Gurgel-Gonçalves
- Núcleo de Medicina Tropical, Faculdade de Medicina, Universidade de Brasília, Brasilia, Brazil
- Laboratório de Parasitologia Médica e Biologia de Vetores, Faculdade de Medicina, Universidade de Brasília, Brasilia, Brazil
| | - Fernando Abad-Franch
- Núcleo de Medicina Tropical, Faculdade de Medicina, Universidade de Brasília, Brasilia, Brazil
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Hollingsworth B, Hawkins P, Lloyd AL, Reiskind MH. Efficacy and Spatial Extent of Yard-Scale Control of Aedes (Stegomyia) albopictus (Diptera: Culicidae) Using Barrier Sprays and Larval Habitat Management. JOURNAL OF MEDICAL ENTOMOLOGY 2020; 57:1104-1110. [PMID: 32052026 PMCID: PMC7768675 DOI: 10.1093/jme/tjaa016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Indexed: 06/10/2023]
Abstract
The Asian tiger mosquito, Aedes (Stegomyia) albopictus (Skuse), is a peridomestic, container-ovipositing mosquito commonly found throughout the southeastern United States. In the United States, Ae. albopictus is typically considered a nuisance pest; however, it is capable of transmitting multiple pathogens. Ae. albopictus is an important pest species and the target of numerous mosquito control efforts in the United States. Here, we evaluate the effectiveness and spatial extent of Ae. albopictus population reduction using a bifenthrin (AI Bifen IT, 7.9%) barrier spray and larval habitat management (LHM) in a temperate, suburban setting. Sixteen pairs of adjoining neighbors were randomly assigned to treatment groups with one neighbor receiving a treatment and the other monitored for evidence of a spillover effect of the treatments. Ae. albopictus populations in both yards were monitored for 33 d, with treatments occurring on the eighth day. Barrier sprays, both alone and combined with LHM, resulted in a significant reduction in Ae. albopictus abundance posttreatment. While LHM alone did not result in a significant reduction over the entire posttreatment period, Ae. albopictus populations were observed to be in decline during this period. No treatments were observed to have any reduction in efficacy 25 d posttreatment, with treatments involving LHM having a significantly increased efficacy. Yards neighboring treated yards were also observed to have reduced population sizes posttreatment, but these differences were rarely significant. These results provide insights into the population dynamics of Ae. albopictus following two common treatments and will be useful for integrated pest management plans.
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Affiliation(s)
| | | | - Alun L Lloyd
- Biomathematics Graduate Program, North Carolina State University, Raleigh, NC
- Department of Mathematics, North Carolina State University, Raleigh, NC
| | - Michael H Reiskind
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC
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Syafruddin D, Asih PBS, Rozi IE, Permana DH, Nur Hidayati AP, Syahrani L, Zubaidah S, Sidik D, Bangs MJ, Bøgh C, Liu F, Eugenio EC, Hendrickson J, Burton T, Baird JK, Collins F, Grieco JP, Lobo NF, Achee NL. Efficacy of a Spatial Repellent for Control of Malaria in Indonesia: A Cluster-Randomized Controlled Trial. Am J Trop Med Hyg 2020; 103:344-358. [PMID: 32431275 PMCID: PMC7356406 DOI: 10.4269/ajtmh.19-0554] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
A cluster-randomized, double-blinded, placebo-controlled trial was conducted to estimate the protective efficacy (PE) of a spatial repellent (SR) against malaria infection in Sumba, Indonesia. Following radical cure in 1,341 children aged ≥ 6 months to ≤ 5 years in 24 clusters, households were given transfluthrin or placebo passive emanators (devices designed to release vaporized chemical). Monthly blood screening and biweekly human-landing mosquito catches were performed during a 10-month baseline (June 2015-March 2016) and a 24-month intervention period (April 2016-April 2018). Screening detected 164 first-time infections and an accumulative total of 459 infections in 667 subjects in placebo-control households, and 134 first-time and 253 accumulative total infections among 665 subjects in active intervention households. The 24-cluster protective effect of 27.7% and 31.3%, for time to first-event and overall (total new) infections, respectively, was not statistically significant. Purportedly, this was due in part to zero to low incidence in some clusters, undermining the ability to detect a protective effect. Subgroup analysis of 19 clusters where at least one infection occurred during baseline showed 33.3% (P-value = 0.083) and 40.9% (P-value = 0.0236, statistically significant at the one-sided 5% significance level) protective effect to first infection and overall infections, respectively. Among 12 moderate- to high-risk clusters, a statistically significant decrease in infection by intervention was detected (60% PE). Primary entomological analysis of impact was inconclusive. Although this study suggests SRs prevent malaria, additional evidence is required to demonstrate the product class provides an operationally feasible and effective means of reducing malaria transmission.
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Affiliation(s)
- Din Syafruddin
- Department of Parasitology, Faculty of Medicine, Universitas Hasanuddin, Makassar, Indonesia.,Eijkman Institute for Molecular Biology, Jakarta, Indonesia
| | - Puji B S Asih
- Eijkman Institute for Molecular Biology, Jakarta, Indonesia
| | | | | | | | - Lepa Syahrani
- Eijkman Institute for Molecular Biology, Jakarta, Indonesia
| | - Siti Zubaidah
- Eijkman Institute for Molecular Biology, Jakarta, Indonesia
| | - Dian Sidik
- Department of Epidemiology, Faculty of Public Health, Universitas Hasanuddin, Makassar, Indonesia
| | - Michael J Bangs
- Public Health and Malaria Control, PT Freeport Indonesia, International SOS, Kuala Kencana, Papua, Indonesia
| | - Claus Bøgh
- The Sumba Foundation, Public Health and Malaria Control, Bali, Indonesia
| | - Fang Liu
- Department of Applied and Computational Mathematics and Statistics, University of Notre Dame, Notre Dame, Indiana
| | - Evercita C Eugenio
- Department of Applied and Computational Mathematics and Statistics, University of Notre Dame, Notre Dame, Indiana
| | - Jared Hendrickson
- Center for Computer Research, University of Notre Dame, Notre Dame, Indiana
| | - Timothy Burton
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana
| | - J Kevin Baird
- Nuffield Department of Medicine, Centre for Tropical Medicine, University of Oxford, Oxford, United Kingdom.,Eijkman-Oxford Clinical Research Unit, Jakarta, Indonesia
| | - Frank Collins
- Center for Computer Research, University of Notre Dame, Notre Dame, Indiana
| | - John P Grieco
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana
| | - Neil F Lobo
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana
| | - Nicole L Achee
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana
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40
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Killeen GF. Control of malaria vectors and management of insecticide resistance through universal coverage with next-generation insecticide-treated nets. Lancet 2020; 395:1394-1400. [PMID: 32304648 DOI: 10.1016/s0140-6736(20)30745-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 03/15/2020] [Accepted: 03/17/2020] [Indexed: 12/23/2022]
Affiliation(s)
- Gerry F Killeen
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Ifakara, Tanzania; School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland.
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41
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Lenhart A, Morrison AC, Paz-Soldan VA, Forshey BM, Cordova-Lopez JJ, Astete H, Elder JP, Sihuincha M, Gotlieb EE, Halsey ES, Kochel TJ, Scott TW, Alexander N, McCall PJ. The impact of insecticide treated curtains on dengue virus transmission: A cluster randomized trial in Iquitos, Peru. PLoS Negl Trop Dis 2020; 14:e0008097. [PMID: 32275653 PMCID: PMC7176142 DOI: 10.1371/journal.pntd.0008097] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 04/22/2020] [Accepted: 01/28/2020] [Indexed: 11/18/2022] Open
Abstract
Dengue is one of the most important vector-borne diseases, resulting in an estimated hundreds of millions of infections annually throughout the tropics. Control of dengue is heavily dependent upon control of its primary mosquito vector, Aedes aegypti. Innovative interventions that are effective at targeting the adult stage of the mosquito are needed to increase the options for effective control. The use of insecticide-treated curtains (ITCs) has previously been shown to significantly reduce the abundance of Ae. aegypti in and around homes, but the impact of ITCs on dengue virus (DENV) transmission has not been rigorously quantified. A parallel arm cluster-randomized controlled trial was conducted in Iquitos, Peru to quantify the impact of ITCs on DENV seroconversion as measured through plaque-reduction neutralization tests. Seroconversion data showed that individuals living in the clusters that received ITCs were at greater risk to seroconverting to DENV, with an average seroconversion rate of 50.6 per 100 person-years (PY) (CI: 29.9–71.9), while those in the control arm had an average seroconversion rate of 37.4 per 100 PY (CI: 15.2–51.7). ITCs lost their insecticidal efficacy within 6 months of deployment, necessitating re-treatment with insecticide. Entomological indicators did not show statistically significant differences between ITC and non-ITC clusters. It’s unclear how the lack of protective efficacy reported here is attributable to simple failure of the intervention to protect against Ae. aegypti bites, or the presence of a faulty intervention during much of the follow-up period. The higher risk of dengue seroconversion that was detected in the ITC clusters may have arisen due to a false sense of security that inadvertently led to less routine protective behaviors on the part of households that received the ITCs. Our study provides important lessons learned for conducting cluster randomized trials for vector control interventions against Aedes-transmitted virus infections. Dengue is one of the most important mosquito-borne diseases affecting humans, resulting in an estimated hundreds of millions of infections annually throughout the tropics. To control dengue, most public health programs use a variety of methods to kill the primary mosquito vector, Aedes aegypti. Water holding containers that harbor larvae (and other immature stages) are treated or eliminated. During emergencies, large insecticide spray campaigns are deployed to kill infected adult mosquitoes. Innovative interventions that are effective at targeting adult mosquitoes in sustainable ways are needed to increase the options for control of dengue and other Aedes borne virus diseases. The use of insecticide-treated curtains (ITCs) has previously been shown to significantly reduce Ae. aegypti numbers in and around homes, but the impact of ITCs on dengue virus (DENV) transmission has not previously been quantified. Using a rigorous study design in which 10 clusters (~90 houses per cluster) were provided multiple ITCs to place in their homes was compared to 10 clusters of homes without ITCs. Assignment of which clusters received ITCs was randomized. Blood samples were obtained at 9-month intervals from residents living in all the clusters, so that people with serological evidence of a DENV infection could be identified by comparing paired samples. Seroconversion data showed that individuals living in the clusters that received ITCs were at greater risk to DENV seroconverting, with an average seroconversion rate of 50.6 per 100 person-years (PY) (CI: 29.9–71.9). Conversely, those in the control arm had an average seroconversion rate of 37.4 per 100 PY (CI: 15.2–51.7). ITCs lost their insecticidal efficacy within 6 months of deployment, necessitating re-treatment with insecticide. Ae. aegypti populations did not show statistically significant differences between ITC and non-ITC clusters. The reason for higher transmission in the ITC treated clusters could be attributable to failure of the curtains (loss of efficacy) and/or that the curtains were not sufficiently effective at protecting against mosquito bites. The higher risk of DENV seroconversion in ITC clusters may be due to a false sense of security that inadvertently led to less routine protective behaviors on the part of households that received the ITC.
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Affiliation(s)
- Audrey Lenhart
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Amy C. Morrison
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, California, United States of America
- Department of Virology, U.S. Naval Medical Research Unit-6, Lima and Iquitos, Peru
- * E-mail:
| | - Valerie A. Paz-Soldan
- Department of Global Community Health and Behavioral Sciences, Tulane School of Public Health and Tropical Medicine, New Orleans, Louisiana, United States of America
- Facultad de Salud Pública y Administración, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Brett M. Forshey
- Department of Virology, U.S. Naval Medical Research Unit-6, Lima and Iquitos, Peru
| | - Jhonny J. Cordova-Lopez
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, California, United States of America
| | - Helvio Astete
- Department of Virology, U.S. Naval Medical Research Unit-6, Lima and Iquitos, Peru
| | - John P. Elder
- San Diego State University, San Diego, California, United States of America
| | - Moises Sihuincha
- Director, Department of Internal Medicine, Hospital de Apoyo Iquitos, Peru
| | - Esther E. Gotlieb
- Department of Global Community Health and Behavioral Sciences, Tulane School of Public Health and Tropical Medicine, New Orleans, Louisiana, United States of America
| | - Eric S. Halsey
- Department of Virology, U.S. Naval Medical Research Unit-6, Lima and Iquitos, Peru
| | - Tadeusz J. Kochel
- Department of Virology, U.S. Naval Medical Research Unit-6, Lima and Iquitos, Peru
| | - Thomas W. Scott
- Department of Entomology and Nematology, University of California, Davis, California, United States of America
| | - Neal Alexander
- MRC Tropical Epidemiology Group, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Philip J. McCall
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
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42
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Taking the 'I' out of LLINs: using insecticides in vector control tools other than long-lasting nets to fight malaria. Malar J 2020; 19:73. [PMID: 32059675 PMCID: PMC7023706 DOI: 10.1186/s12936-020-3151-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 02/05/2020] [Indexed: 11/23/2022] Open
Abstract
Long-lasting insecticidal nets, or LLINs, have significantly reduced malaria morbidity and mortality over the past two decades. The net provides a physical barrier that decreases human-mosquito contact and the impregnated insecticide kills susceptible mosquito vectors upon contact and may repel them. However, the future of LLINs is threatened as resistance to pyrethroids is now widespread, the chemical arsenal for LLINs is very limited, time from discovery of next-generation insecticides to market is long, and persistent transmission is frequently caused by vector populations avoiding contact with LLINs. Here we ask the question whether, given these challenges, insecticides should be incorporated in nets at all. We argue that developing long-lasting nets without insecticide(s) can still reduce vector populations and provide both personal and community protection, if combined with other approaches or technologies. Taking the insecticide out of the equation (i) allows for a faster response to the current pyrethroid resistance crisis, (ii) avoids an LLIN-treadmill aimed at replacing failing bed nets due to insecticide resistance, and (iii) permits the utilization of our current and future insecticidal arsenal for other vector control tools to target persistent malaria transmission.
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43
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Nazareth T, Craveiro I, Moutinho A, Seixas G, Gonçalves C, Gonçalves L, Teodósio R, Sousa CA. What happens when we modify mosquitoes for disease prevention? A systematic review. Emerg Microbes Infect 2020; 9:348-365. [PMID: 32041484 PMCID: PMC7034073 DOI: 10.1080/22221751.2020.1722035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 01/10/2020] [Accepted: 01/19/2020] [Indexed: 12/12/2022]
Abstract
The release of modified mosquitoes to suppress/replace vectors constitutes a promising tool for vector control and disease prevention. Evidence regarding these innovative modification techniques is scarce and disperse. This work conducted a systematic review, gathering and analysing research articles from PubMed and Biblioteca Virtual em Saúde databases whose results report efficacy and non-target effects of using modified insects for disease prevention, until 2016. More than 1500 publications were screened and 349 were analysed. Only 12/3.4% articles reported field-based evidence and 41/11.7% covered modification strategies' post-release efficacy. Variability in the effective results (90/25.7%) questioned its reproducibility in different settings. We also found publications reporting reversal outcomes 38/10.9%, (e.g. post-release increase of vector population). Ecological effects were also reported, such as horizontal transfer events (54/15.5%), and worsening pathogenesis induced by natural wolbachia (10/2.9%). Present work revealed promising outcomes of modifying strategies. However, it also revealed a need for field-based evidence mainly regarding epidemiologic and long-term impact. It pointed out some eventual irreversible and important effects that must not be ignored when considering open-field releases, and that may constitute constraints to generate the missing field evidence. Present work constitutes a baseline of knowledge, offering also a methodological approach that may facilitate future updates.
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Affiliation(s)
- Teresa Nazareth
- UEI Parasitologia Médica, Global Health and Tropical Medicine (GHTM), Instituto de Higiene e Medicina Tropical (IHMT), Universidade Nova de Lisboa (UNL), Lisboa, Portugal
| | - Isabel Craveiro
- UEI Bioestatística e Sáude Internacional, Global Health and Tropical Medicine (GHTM), Instituto de Higiene e Medicina Tropical (IHMT), Universidade Nova de Lisboa (UNL), Lisboa, Portugal
| | - Alanny Moutinho
- UEI Parasitologia Médica, Global Health and Tropical Medicine (GHTM), Instituto de Higiene e Medicina Tropical (IHMT), Universidade Nova de Lisboa (UNL), Lisboa, Portugal
| | - Gonçalo Seixas
- UEI Parasitologia Médica, Global Health and Tropical Medicine (GHTM), Instituto de Higiene e Medicina Tropical (IHMT), Universidade Nova de Lisboa (UNL), Lisboa, Portugal
| | - Cátia Gonçalves
- Nova School of Business and Economics, Universidade NOVA de Lisboa, Lisboa, Portugal
| | - Luzia Gonçalves
- UEI Bioestatística e Sáude Internacional, Global Health and Tropical Medicine (GHTM), Instituto de Higiene e Medicina Tropical (IHMT), Universidade Nova de Lisboa (UNL), Lisboa, Portugal
- Centro de Estatística e Aplicações, Universidade de Lisboa, Lisboa, Portugal
| | - Rosa Teodósio
- UEI Parasitologia Médica, Global Health and Tropical Medicine (GHTM), Instituto de Higiene e Medicina Tropical (IHMT), Universidade Nova de Lisboa (UNL), Lisboa, Portugal
- UEI Clínica Tropical, Global Health and Tropical Medicine, (GHTM), Instituto de Higiene e Medicina Tropical (IHMT), Universidade Nova de Lisboa (UNL), Lisboa, Portugal
| | - Carla A. Sousa
- UEI Parasitologia Médica, Global Health and Tropical Medicine (GHTM), Instituto de Higiene e Medicina Tropical (IHMT), Universidade Nova de Lisboa (UNL), Lisboa, Portugal
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44
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Bouyer J, Yamada H, Pereira R, Bourtzis K, Vreysen MJB. Phased Conditional Approach for Mosquito Management Using Sterile Insect Technique. Trends Parasitol 2020; 36:325-336. [PMID: 32035818 DOI: 10.1016/j.pt.2020.01.004] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 01/15/2020] [Accepted: 01/15/2020] [Indexed: 12/18/2022]
Abstract
Mosquito-borne diseases represent a major threat to humankind. Recently, the incidence of malaria has stopped decreasing while that of dengue is increasing exponentially. Alternative mosquito-control methods are urgently needed. The sterile insect technique (SIT) has seen significant developments recently and may play an important role. However, testing and implementing SIT for vector control is challenging, and a phased conditional approach (PCA) is recommended, that is, advancement to the next phase depends on completion of activities in the previous one. We herewith present a PCA to test the SIT against mosquitoes within an area-wide-integrated pest-management programme, taking into account the experience gained with plant and livestock pests and the recent developments of the technique against mosquitoes.
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Affiliation(s)
- Jérémy Bouyer
- Insect Pest Control Sub-programme, Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, A-1400 Vienna, Austria; CIRAD, UMR ASTRE CIRAD-INRA 'AnimalS, health, Territories, Risks and Ecosystems', Campus International de Baillarguet, 34398 Montpellier Cedex 05, France.
| | - Hanano Yamada
- Insect Pest Control Sub-programme, Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, A-1400 Vienna, Austria
| | - Rui Pereira
- Insect Pest Control Sub-programme, Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, A-1400 Vienna, Austria
| | - Kostas Bourtzis
- Insect Pest Control Sub-programme, Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, A-1400 Vienna, Austria
| | - Marc J B Vreysen
- Insect Pest Control Sub-programme, Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, A-1400 Vienna, Austria
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45
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Leptolegnia chapmanii como alternativa biológica para el control de Aedes aegypti. ACTA ACUST UNITED AC 2019; 39:798-810. [PMID: 31860189 PMCID: PMC7363348 DOI: 10.7705/biomedica.4598] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Indexed: 11/21/2022]
Abstract
Leptolegnia chapmanii is a facultative pathogen of many species of mosquitoes, among which species of the genus Aedes, Culex and Anopheles stand out for their medical and sanitary importance. The potential of L. chapmanii as an alternative to control lies in its virulence, pathogenicity and specificity against the larval stages of mosquitoes, and because of its harmlessness to non-target species such as fish and amphibians, among others. The natural presence of L. chapmanii had been reported in Argentina, Brazil and the United States. Its presence is possible in other countries throughout the American continent. The development of protocols to produce, formulate, store and apply products based on this microorganism is one of the objectives proposed for the group of Entomopathogenic Fungi at the Centro de Estudios Parasitológicos y de Vectores, Universidad Nacional de La Plata. The efficacy of L. chapmanii as controller is affected by external factors such as temperature, pH, salinity and radiation among others. The process of transfer from the research centers to industry implies many phases. In this way, our project with L. chapmanii is in an initial phase, where we are working on a laboratory scale in proof of concept. We hope to begin soon with the efficacy, efficiency, stability and ecotoxicological safety tests, at the laboratory, semi-field and field scale.
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46
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Disease Resurgence, Production Capability Issues and Safety Concerns in the Context of an Aging Population: Is There a Need for a New Yellow Fever Vaccine? Vaccines (Basel) 2019; 7:vaccines7040179. [PMID: 31717289 PMCID: PMC6963298 DOI: 10.3390/vaccines7040179] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 10/28/2019] [Accepted: 11/05/2019] [Indexed: 12/19/2022] Open
Abstract
Yellow fever is a potentially fatal, mosquito-borne viral disease that appears to be experiencing a resurgence in endemic areas in Africa and South America and spreading to non-endemic areas despite an effective vaccine. This trend has increased the level of concern about the disease and the potential for importation to areas in Asia with ecological conditions that can sustain yellow fever virus transmission. In this article, we provide a broad overview of yellow fever burden of disease, natural history, treatment, vaccine, prevention and control initiatives, and vaccine and therapeutic agent development efforts.
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47
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Indriani C, Ahmad RA, Wiratama BS, Arguni E, Supriyati E, Sasmono RT, Kisworini FY, Ryan PA, O'Neill SL, Simmons CP, Utarini A, Anders KL. Baseline Characterization of Dengue Epidemiology in Yogyakarta City, Indonesia, before a Randomized Controlled Trial of Wolbachia for Arboviral Disease Control. Am J Trop Med Hyg 2019; 99:1299-1307. [PMID: 30226138 PMCID: PMC6221224 DOI: 10.4269/ajtmh.18-0315] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Dengue is endemic in Indonesia. Here, we describe the epidemiology of dengue in the city of Yogyakarta, Central Java, as a prelude to implementation of a cluster-randomized trial of Wolbachia for the biocontrol of arboviral transmission. Surveillance records from 2006 to 2016 demonstrate seasonal oscillations of dengue incidence with varying magnitude. Two lines of evidence demonstrate a high force of infection; the hospitalized case burden of patients diagnosed with dengue hemorrhagic fever or dengue shock syndrome over the last decade consisted predominantly of children/adolescents, and a serosurvey of 314 healthy children aged 1–10 years found 68% possessed dengue virus–neutralizing antibodies. Finally, a mobility survey indicated children aged 1–10 years, and particularly 1–5 year-olds, spent most of their daytime hours at home. These findings inform the design of clinical trials to measure the impact of novel vector control methods such as Wolbachia introgression into Aedes aegypti mosquitoes, by providing baseline data on disease incidence and identifying subpopulations for recruitment into prospective studies of dengue virus infection and disease. The mobility survey findings indicate that in cluster trials of interventions applied at the community level, young children can reasonably be expected to spend most of their exposure time, in epidemiological terms, within the treatment arm to which they were randomized.
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Affiliation(s)
- Citra Indriani
- Department of Epidemiology, Biostatistics and Population Health, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia.,Centre of Tropical Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Riris A Ahmad
- Department of Epidemiology, Biostatistics and Population Health, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia.,Centre of Tropical Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Bayu S Wiratama
- Department of Epidemiology, Biostatistics and Population Health, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia.,Centre of Tropical Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Eggi Arguni
- Department of Pediatrics, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia.,Centre of Tropical Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Endah Supriyati
- Centre of Tropical Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | | | | | - Peter A Ryan
- Institute of Vector Borne Disease, Monash University, Melbourne, Australia
| | - Scott L O'Neill
- Institute of Vector Borne Disease, Monash University, Melbourne, Australia
| | - Cameron P Simmons
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam.,Institute of Vector Borne Disease, Monash University, Melbourne, Australia
| | - Adi Utarini
- Department of Health Policy and Management, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia.,Centre of Tropical Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Katherine L Anders
- Institute of Vector Borne Disease, Monash University, Melbourne, Australia
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48
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Beard CB, Visser SN, Petersen LR. The Need for a National Strategy to Address Vector-Borne Disease Threats in the United States. JOURNAL OF MEDICAL ENTOMOLOGY 2019; 56:1199-1203. [PMID: 31505668 PMCID: PMC7058377 DOI: 10.1093/jme/tjz074] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Indexed: 05/19/2023]
Abstract
Vector-borne diseases (VBDs) cause significant morbidity and mortality each year in the United States. Over the last 14 yr, over 700,000 cases of diseases carried by ticks, mosquitoes, and fleas have been reported from U.S. states and territories to the Centers for Disease Control and Prevention. The number of reported cases has been increasing annually with two major trends: a steady increase in tick-borne diseases and increasing intermittent outbreaks of mosquito-borne arboviruses. The factors that are driving VBD introduction and emergence vary among diseases but are not likely to disappear, indicating that current trends will continue and probably worsen in the absence of effective prevention and control tools and implementation capacity. There are a number of challenges to preventing VBDs, including the lack of vaccines and effective vector control tools, insecticide resistance, and eroding technical capacities in public health entomology at federal, state, and local levels. For these reasons, a national strategy is needed to address VBD threats and to reverse the alarming trend in morbidity and mortality associated with these diseases.
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49
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Jewell NP, Dufault S, Cutcher Z, Simmons CP, Anders KL. Analysis of cluster-randomized test-negative designs: cluster-level methods. Biostatistics 2019; 20:332-346. [PMID: 29447357 DOI: 10.1093/biostatistics/kxy005] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 01/13/2018] [Indexed: 12/24/2022] Open
Abstract
Intervention trials of vector control methods often require community level randomization with appropriate inferential methods. For many interventions, the possibility of confounding due to the effects of health-care seeking behavior on disease ascertainment remains a concern. The test-negative design, a variant of the case-control method, was introduced to mitigate this issue in the assessment of the efficacy of influenza vaccination (measured at an individual level) on influenza infection. Here, we introduce a cluster-randomized test-negative design that includes randomization of the intervention at a group level. We propose several methods for estimation and inference regarding the relative risk (RR). The inferential methods considered are based on the randomization distribution induced by permuting intervention assignment across two sets of randomly selected clusters. The motivating example is a current study of the efficacy of randomized releases of Wolbachia-infected Aedes aegypti mosquitoes to reduce the incidence of dengue in Yogyakarta City, Indonesia. Estimation and inference techniques are assessed through a simulation study.
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Affiliation(s)
- Nicholas P Jewell
- Division of Biostatistics, School of Public Health, University of California, Berkeley, CA 94720, USA
| | - Suzanne Dufault
- Division of Biostatistics, School of Public Health, University of California, Berkeley, CA 94720, USA
| | - Zoe Cutcher
- World Mosquito Program, Institute of Vector Borne Disease, Monash University, Level 1, 12 Innovation Walk, Clayton, Victoria 3800, Australia
| | - Cameron P Simmons
- World Mosquito Program, Institute of Vector Borne Disease, Monash University, Level 1, 12 Innovation Walk, Clayton, Victoria 3800, Australia
| | - Katherine L Anders
- World Mosquito Program, Institute of Vector Borne Disease, Monash University, Level 1, 12 Innovation Walk, Clayton, Victoria 3800, Australia
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50
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Abstract
BACKGROUND Larviciding refers to the regular application of chemical or microbial insecticides to water bodies or water containers to kill the aquatic immature forms of the mosquito (the larvae and pupae). OBJECTIVES To summarize research evidence evaluating whether larviciding with chemical or microbial insecticides prevents malaria transmission. SEARCH METHODS We searched the Cochrane Infectious Diseases Group Specialized Register; the Cochrane Central Register of Controlled Trials (CENTRAL), published in the Cochrane Library; MEDLINE; Embase; CAB Abstracts; LILACS; the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP); ClinicalTrials.gov; and the ISRCTN registry up to 6 June 2019. SELECTION CRITERIA We included cluster-randomized controlled trials (cRCTs), interrupted time series (ITS), randomized cross-over studies, non-randomized cross-over studies, and controlled before-and-after studies (CBAs) that compared larviciding with no larviciding. DATA COLLECTION AND ANALYSIS We independently assessed trials for eligibility and risk of bias, and extracted data. We assessed the certainty of evidence using the GRADE approach. MAIN RESULTS Four studies (one cRCT, two CBAs, and one non-randomized cross-over design) met the inclusion criteria. All used ground application of larvicides (people hand-delivering larvicides); one evaluated chemical and three evaluated microbial agents. Studies were carried out in The Gambia, Tanzania, Kenya, and Sri Lanka. Three studies were conducted in areas where mosquito aquatic habitats were less extensive (< 1 km²), and one where habitats were more extensive (> 1 km²; a cross-over study from The Gambia).For aquatic habitats of less than 1 km², one cRCT randomized eight villages in Sri Lanka to evaluate chemical larviciding using insect growth regulator; and two CBA studies undertaken in Kenya and Tanzania evaluated microbial larvicides. In the cRCT, larviciding across all villages was associated with lower malaria incidence (rate ratio 0.24, 4649 participants, low-certainty evidence) and parasite prevalence (risk ratio (RR) 0.26, 5897 participants, low-certainty evidence) compared to no larviciding. The two CBA studies reported lower malaria prevalence during the intervention period (parasite prevalence RR 0.79, 95% confidence interval (CI) 0.71 to 0.89; 70,902 participants; low-certainty evidence). The Kenyan study also reported a reduction in the incidence of new malaria cases (RR 0.62, 95% CI 0.38 to 1.01; 720 participants; very low-certainty evidence).For aquatic habitats of more than 1 km², the non-randomized cross-over trial using microbial larvicides did not detect an effect for malaria incidence (RR 1.58, 95% CI 0.94 to 2.65; 4226 participants), or parasite prevalence (RR 1.15, 95% CI 0.41 to 3.20; 3547 participants); both were very low-certainty evidence. The Gambia trial also reported the mean haemoglobin level, and there was no difference across the four comparisons (mean difference -0.13, 95% CI -0.40 to 0.13; 3586 participants).We were unable to summarize or pool entomological outcomes due to unreported and missing data. AUTHORS' CONCLUSIONS Most controlled studies on larviciding have been performed with microbial agents. Ground larviciding for non-extensive larval habitats may have an effect on malaria transmission, and we do not know if there is an effect in large-scale aquatic habitats. We found no studies using larviciding application techniques that could cover large aquatic habitats, such as aerial spraying using aircraft.
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Affiliation(s)
- Leslie Choi
- Liverpool School of Tropical MedicineDepartment of Clinical SciencesPembroke PlaceLiverpoolUKL3 5QA
| | | | - Anne L Wilson
- Durham UniversityDepartment of BiosciencesStockton RoadDurhamUK
- Liverpool School of Tropical MedicineDepartment of Vector BiologyLiverpoolUK
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