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Zeledon EV, Baxt LA, Khan TA, Michino M, Miller M, Huggins DJ, Jiang CS, Vosshall LB, Duvall LB. Next Generation Neuropeptide Y Receptor Small Molecule Agonists Inhibit Mosquito Biting Behavior. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.28.582529. [PMID: 38464241 PMCID: PMC10925335 DOI: 10.1101/2024.02.28.582529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Female Aedes aegypti mosquitoes can spread disease-causing pathogens when they bite humans to obtain blood nutrients required for egg production. Following a complete blood meal, host-seeking is suppressed until eggs are laid. Neuropeptide Y-like Receptor 7 (NPYLR7) plays a role in endogenous host-seeking suppression and previous work identified small molecule NPYLR7 agonists that suppress host-seeking and blood feeding when fed to mosquitoes at high micromolar doses. Using structure activity relationship analysis and structure-guided design we synthesized 128 compounds with similarity to known NPYLR7 agonists. Although in vitro potency (EC50) was not strictly predictive of in vivo effect, we identified 3 compounds that suppressed blood feeding from a live host when fed to mosquitoes at a 1 μM dose, a 100-fold improvement over the original reference compound. Exogenous activation of NPYLR7 represents an innovative vector control strategy to block mosquito biting behavior and prevent mosquito/human host interactions that lead to pathogen transmission.
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Affiliation(s)
- Emely V. Zeledon
- Laboratory of Neurogenetics and Behavior, The Rockefeller University, New York NY 10065, USA
- Howard Hughes Medical Institute, New York NY 10065, USA
| | - Leigh A. Baxt
- Sanders Tri-Institutional Therapeutics Discovery Institute, New York, New York 10065, USA
| | - Tanweer A. Khan
- Sanders Tri-Institutional Therapeutics Discovery Institute, New York, New York 10065, USA
| | - Mayako Michino
- Sanders Tri-Institutional Therapeutics Discovery Institute, New York, New York 10065, USA
| | - Michael Miller
- Sanders Tri-Institutional Therapeutics Discovery Institute, New York, New York 10065, USA
| | - David J. Huggins
- Sanders Tri-Institutional Therapeutics Discovery Institute, New York, New York 10065, USA
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York NY 10065, USA
| | - Caroline S. Jiang
- Center for Clinical and Translational Science, The Rockefeller University, New York, NY 10065, USA
| | - Leslie B. Vosshall
- Laboratory of Neurogenetics and Behavior, The Rockefeller University, New York NY 10065, USA
- Howard Hughes Medical Institute, New York NY 10065, USA
- Kavli Neural Systems Institute, New York, NY 10065, USA
| | - Laura B. Duvall
- Department of Biological Sciences, Columbia University, New York NY 10027, USA
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Kamber L, Bürli C, Harbrecht H, Odermatt P, Sayasone S, Chitnis N. Modeling the persistence of Opisthorchis viverrini worm burden after mass-drug administration and education campaigns with systematic adherence. PLoS Negl Trop Dis 2024; 18:e0011362. [PMID: 38422118 DOI: 10.1371/journal.pntd.0011362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 03/12/2024] [Accepted: 01/23/2024] [Indexed: 03/02/2024] Open
Abstract
Opisthorchis viverrini is a parasitic liver fluke contracted by consumption of raw fish, which affects over 10 million people in Southeast Asia despite sustained control efforts. Chronic infections are a risk factor for the often fatal bile duct cancer, cholangiocarcinoma. Previous modeling predicted rapid elimination of O. viverrini following yearly mass drug administration (MDA) campaigns. However, field data collected in affected populations shows persistence of infection, including heavy worm burden, after many years of repeated interventions. A plausible explanation for this observation is systematic adherence of individuals in health campaigns, such as MDA and education, with some individuals consistently missing treatment. We developed an agent-based model of O. viverrini which allows us to introduce various heterogeneities including systematic adherence to MDA and education campaigns at the individual level. We validate the agent-based model by comparing it to a previously published population-based model. We estimate the degree of systematic adherence to MDA and education campaigns indirectly, using epidemiological data collected in Lao PDR before and after 5 years of repeated MDA, education and sanitation improvement campaigns. We predict the impact of interventions deployed singly and in combination, with and without the estimated systematic adherence. We show how systematic adherence can substantially increase the time required to achieve reductions in worm burden. However, we predict that yearly MDA campaigns alone can result in a strong reduction of moderate and heavy worm burden, even under systematic adherence. We predict latrines and education campaigns to be particularly important for the reduction in overall prevalence, and therefore, ultimately, elimination. Our findings show how systematic adherence can explain the observed persistence of worm burden; while emphasizing the benefit of interventions for the entire population, even under systematic adherence. At the same time, the results highlight the substantial opportunity to further reduce worm burden if patterns of systematic adherence can be overcome.
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Affiliation(s)
- Lars Kamber
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Christine Bürli
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Helmut Harbrecht
- Department of Mathematics and Computer Science, University of Basel, Basel, Switzerland
| | - Peter Odermatt
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Somphou Sayasone
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
- Lao Tropical and Public Health Institute, Vientiane, Lao People's Democratic Republic
| | - Nakul Chitnis
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
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da Silva RJ, Cabo LF, George JL, Cahoon LA, Yang L, Coyne CB, Boyle JP. Human trophoblast stem cells can be used to model placental susceptibility to Toxoplasma gondii and highlight the critical importance of the trophoblast cell surface in pathogen resistance. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.10.566663. [PMID: 37986837 PMCID: PMC10659356 DOI: 10.1101/2023.11.10.566663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
The placenta is a critical barrier against viral, bacterial, and eukaryotic pathogens. For most teratogenic pathogens, the precise molecular mechanisms of placental resistance are still being unraveled. Given the importance to understand these mechanisms and challenges in replicating trophoblast- pathogen interactions using in vitro models, we tested an existing stem-cell derived model of trophoblast development for its relevance to infection with Toxoplasma gondii . We grew human trophoblast stem cells (TS CT ) under conditions leading to either syncytiotrophoblast (TS SYN ) or cytotrophoblast (TS CYT ) and infected them with T. gondii . We evaluated T. gondii proliferation and invasion, cell ultrastructure, as well as for transcriptome changes after infection. TS SYNs cells showed similar ultrastructure compared to primary cells and villous explants when analyzed by TEM and SEM, a resistance to T. gondii adhesion could be visualized on the SEM level. Furthermore, TS SYNs were highly refractory to parasite adhesion and replication, while TS CYT were not. RNA-seq data on mock-treated and infected cells identified differences between cell types as well as how they responded to T. gondii infection. We also evaluated if TS SC -derived SYNs and CYTs had distinct resistance profiles to another vertically transmitted facultative intracellular pathogen, Listeria monocytogenes . We demonstrate that TS SYNs are highly resistant to L. monocytogenes , while TS CYTs are not. Like T. gondii , TS SYN resistance to L. monocytogenes was at the level of bacterial adhesion. Altogether, our data indicate that stem-cell derived trophoblasts recapitulate resistance profiles of primary cells to T. gondii and highlight the critical importance of the placental surface in cell-autonomous resistance to teratogens.
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Pennance T, Calvelo J, Tennessen JA, Burd R, Cayton J, Bollmann SR, Blouin MS, Spaan JM, Hoffmann FG, Ogara G, Rawago F, Andiego K, Mulonga B, Odhiambo M, Loker ES, Laidemitt MR, Lu L, Iriarte A, Odiere M, Steinauer ML. The genome and transcriptome of the snail Biomphalaria sudanica s.l.: Immune gene diversification and highly polymorphic genomic regions in an important African vector of Schistosoma mansoni. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.01.565203. [PMID: 37961413 PMCID: PMC10635097 DOI: 10.1101/2023.11.01.565203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Background Control and elimination of schistosomiasis is an arduous task, with current strategies proving inadequate to break transmission. Exploration of genetic approaches to interrupt Schistosoma mansoni transmission, the causative agent for human intestinal schistosomiasis in sub-Saharan Africa and South America, has led to genomic research of the snail vector hosts of the genus Biomphalaria. Few complete genomic resources exist, with African Biomphalaria species being particularly underrepresented despite this being where the majority of S. mansoni infections occur. Here we generate and annotate the first genome assembly of Biomphalaria sudanica sensu lato, a species responsible for S. mansoni transmission in lake and marsh habitats of the African Rift Valley. Supported by whole-genome diversity data among five inbred lines, we describe orthologs of immune-relevant gene regions in the South American vector B. glabrata and present a bioinformatic pipeline to identify candidate novel pathogen recognition receptors (PRRs). Results De novo genome and transcriptome assembly of inbred B. sudanica originating from the shoreline of Lake Victoria (Kisumu, Kenya) resulted in a haploid genome size of ~944.2 Mb (6732 fragments, N50=1.067 Mb), comprising 23,598 genes (BUSCO=93.6% complete). The B. sudanica genome contains orthologues to all described immune genes/regions tied to protection against S. mansoni in B. glabrata. The B. sudanica PTC2 candidate immune genomic region contained many PRR-like genes across a much wider genomic region than has been shown in B. glabrata, as well as a large inversion between species. High levels of intra-species nucleotide diversity were seen in PTC2, as well as in regions linked to PTC1 and RADres orthologues. Immune related and putative PRR gene families were significantly over-represented in the sub-set of B. sudanica genes determined as hyperdiverse, including high extracellular diversity in transmembrane genes, which could be under pathogen-mediated balancing selection. However, no overall expansion in immunity related genes were seen in African compared to South American lineages. Conclusions The B. sudanica genome and analyses presented here will facilitate future research in vector immune defense mechanisms against pathogens. This genomic/transcriptomic resource provides necessary data for the future development of molecular snail vector control/surveillance tools, facilitating schistosome transmission interruption mechanisms in Africa.
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Affiliation(s)
- Tom Pennance
- College of Osteopathic Medicine of the Pacific - Northwest, Western University of Health Sciences, Lebanon OR, USA
| | - Javier Calvelo
- Laboratorio Biología Computacional, Departamento de Desarrollo Biotecnológico, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Montevideo 11600, Uruguay
| | | | - Ryan Burd
- College of Osteopathic Medicine of the Pacific - Northwest, Western University of Health Sciences, Lebanon OR, USA
| | - Jared Cayton
- College of Osteopathic Medicine of the Pacific - Northwest, Western University of Health Sciences, Lebanon OR, USA
| | | | | | - Johannie M Spaan
- College of Osteopathic Medicine of the Pacific - Northwest, Western University of Health Sciences, Lebanon OR, USA
| | - Federico G Hoffmann
- Department of Biochemistry, Molecular Biology, Entomology, and Plant Pathology, Mississippi State University, Starkville, MS USA
| | - George Ogara
- Centre for Global Health Research, Kenya Medical Research Institute (KEMRI), P. O. Box 1578-40100, Kisumu, Kenya
| | - Fredrick Rawago
- Centre for Global Health Research, Kenya Medical Research Institute (KEMRI), P. O. Box 1578-40100, Kisumu, Kenya
| | - Kennedy Andiego
- Centre for Global Health Research, Kenya Medical Research Institute (KEMRI), P. O. Box 1578-40100, Kisumu, Kenya
| | - Boaz Mulonga
- Centre for Global Health Research, Kenya Medical Research Institute (KEMRI), P. O. Box 1578-40100, Kisumu, Kenya
| | - Meredith Odhiambo
- Centre for Global Health Research, Kenya Medical Research Institute (KEMRI), P. O. Box 1578-40100, Kisumu, Kenya
| | - Eric S Loker
- Department of Biology, Center for Evolutionary and Theoretical Immunology, Parasite Division Museum of Southwestern Biology, University of New Mexico, Albuquerque, New Mexico 87131, U.S.A
| | - Martina R Laidemitt
- Department of Biology, Center for Evolutionary and Theoretical Immunology, Parasite Division Museum of Southwestern Biology, University of New Mexico, Albuquerque, New Mexico 87131, U.S.A
| | - Lijun Lu
- Department of Biology, Center for Evolutionary and Theoretical Immunology, Parasite Division Museum of Southwestern Biology, University of New Mexico, Albuquerque, New Mexico 87131, U.S.A
| | - Andrés Iriarte
- Laboratorio Biología Computacional, Departamento de Desarrollo Biotecnológico, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Montevideo 11600, Uruguay
| | - Maurice Odiere
- Department of Biochemistry, Molecular Biology, Entomology, and Plant Pathology, Mississippi State University, Starkville, MS USA
| | - Michelle L Steinauer
- College of Osteopathic Medicine of the Pacific - Northwest, Western University of Health Sciences, Lebanon OR, USA
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Sumboh JG, Agyenkwa-Mawuli K, Schwinger E, Donkor IO, Akorli JEB, Dwomoh D, Ashong Y, Osabutey D, Ababio FO, Koram KA, Humphries D, Cappello M, Kwofie SK, Wilson MD. Investigating Environmental Determinants of Soil-Transmitted Helminths Transmission using GPS Tracking and Metagenomics Technologies. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.07.17.23292808. [PMID: 37503260 PMCID: PMC10371187 DOI: 10.1101/2023.07.17.23292808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Background The Global Health community aims to eliminate soil-transmitted helminth (STH) infections by 2030. Current preventive methods such as Mass Drug Administration, WASH practices, and health education needs to be complimented to halt transmission. We tracked the movement of hookworm-infected and non-infected persons and investigated soil factors in the places they frequented within an endemic community to further understand the role of human movement and sources of infections. Methods 59 positive and negative participants wore GPS tracking devices for 10 consecutive days and their movement data captured in real time. The data was overlaid on the community map to determine where each group differentially spent most of their time. Soil samples were collected from these identified sites and other communal places. Physical and chemical properties were determined for each sample using standard methods and helminth eggs cultured into larvae using the Baermann technique. Bivariate and multivariate analyses were used to determine associations between larvae counts and soil factors. Helminth species were identified with metagenomic sequencing and their distributions mapped to sampling sites in the community. Results The study found that there was no significant difference in the average larvae counts in soil between sites assessed by infected and non-infected participants (P=0.59). However, soil factors, such as pH, carbon and sandy-loamy texture were associated with high larvae counts (P<0.001) while nitrogen and clay content were associated with low counts(P<0.001). The dominant helminth species identified were Panagrolaimus superbus (an anhydrobiotic helminth), Parastrongyloides trichosuri (a parasite of small mammals), Trichuris trichuria (whipworm), and Ancylostoma caninum (dog hookworm). Notably, no Necator americanus was identified in any soil sample. Conclusion This study provides important insights into the association between soil factors and soil-transmitted helminths. These findings contribute to our understanding of STH epidemiology and support evidence-based decision-making for elimination strategies.
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Affiliation(s)
- Jeffrey Gabriel Sumboh
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana. Legon, Accra, Ghana
| | - Kwasi Agyenkwa-Mawuli
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana. Legon, Accra, Ghana
| | - Eyram Schwinger
- Department of Mathematics, University of Ghana. Legon, Accra, Ghana
| | - Irene Owusu Donkor
- Department of Epidemiology, Noguchi Memorial Institute for Medical Research, University of Ghana. Legon, Accra, Ghana
| | - Jewelna E. B. Akorli
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana. Legon, Accra, Ghana
| | - Duah Dwomoh
- Department of Biostatistics, School of Public Health, University of Ghana. Legon, Accra, Ghana
| | - Yvonne Ashong
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana. Legon, Accra, Ghana
| | - Dickson Osabutey
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana. Legon, Accra, Ghana
| | - Felix Owusu Ababio
- Soil Research Institute, Council for Scientific and Industrial Research, Accra, Ghana
| | - Kwadwo Ansah Koram
- Department of Epidemiology, Noguchi Memorial Institute for Medical Research, University of Ghana. Legon, Accra, Ghana
| | - Debbie Humphries
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, United States of America
| | - Michael Cappello
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, United States of America
| | - Samuel K. Kwofie
- School of Biomedical Engineering, Faculty of Engineering, University of Ghana. Legon, Accra, Ghana
| | - Michael D. Wilson
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana. Legon, Accra, Ghana
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Maddren R, Phillips A, Rayment Gomez S, Forbes K, Collyer BS, Kura K, Anderson R. Individual longitudinal compliance to neglected tropical disease mass drug administration programmes, a systematic review. PLoS Negl Trop Dis 2023; 17:e0010853. [PMID: 37459369 PMCID: PMC10374057 DOI: 10.1371/journal.pntd.0010853] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 07/27/2023] [Accepted: 06/05/2023] [Indexed: 07/28/2023] Open
Abstract
Repeated distribution of preventative chemotherapy (PC) by mass drug administration forms the mainstay of transmission control for five of the 20 recognised neglected tropical diseases (NTDs); soil-transmitted helminths, schistosomiasis, lymphatic filariasis, onchocerciasis and trachoma. The efficiency of such programmes is reliant upon participants swallowing the offered treatment consistently at each round. This is measured by compliance, defined as the proportion of eligible participants swallowing treatment. Individually linked longitudinal compliance data is important for assessing the potential impact of MDA-based control programmes, yet this accurate monitoring is rarely implemented in those for NTDs. Longitudinal compliance data reported by control programmes globally for the five (PC)-NTDs since 2016 is examined, focusing on key associations of compliance with age and gender. PubMed and Web of Science was searched in January 2022 for articles written in English and Spanish, and the subsequent extraction adhered to PRISMA guidelines. Study title screening was aided by Rayyan, a machine learning software package. Studies were considered for inclusion if primary compliance data was recorded for more than one time point, in a population larger than 100 participants. All data analysis was conducted in R. A total of 89 studies were identified containing compliance data, 57 were longitudinal studies, of which 25 reported individually linked data reported by varying methods. The association of increasing age with the degree of systematic treatment was commonly reported. The review is limited by the paucity of data published on this topic. The varying and overlapping terminologies used to describe coverage (receiving treatment) and compliance (swallowing treatment) is reviewed. Consequently, it is recommended that WHO considers clearly defining the terms for coverage, compliance, and longitudinal compliance which are currently contradictory across their NTD treatment guidelines. This review is registered with PROSPERO (number: CRD42022301991).
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Affiliation(s)
- Rosie Maddren
- Department of Infectious Disease Epidemiology, Imperial College London, Saint Mary's Campus, Norfolk Place, London, United Kingdom
| | - Anna Phillips
- Department of Infectious Disease Epidemiology, Imperial College London, Saint Mary's Campus, Norfolk Place, London, United Kingdom
- FHI 360, Durham, North Carolina, United States of America
| | - Santiago Rayment Gomez
- Department of Infectious Disease Epidemiology, Imperial College London, Saint Mary's Campus, Norfolk Place, London, United Kingdom
| | - Kathryn Forbes
- Department of Infectious Disease Epidemiology, Imperial College London, Saint Mary's Campus, Norfolk Place, London, United Kingdom
- London Centre for Neglected Tropical Disease Research (LCNTDR), Imperial College London, Saint Mary's Campus, Norfolk Place, London, United Kingdom
| | - Benjamin S Collyer
- Department of Infectious Disease Epidemiology, Imperial College London, Saint Mary's Campus, Norfolk Place, London, United Kingdom
| | - Klodeta Kura
- Department of Infectious Disease Epidemiology, Imperial College London, Saint Mary's Campus, Norfolk Place, London, United Kingdom
| | - Roy Anderson
- Department of Infectious Disease Epidemiology, Imperial College London, Saint Mary's Campus, Norfolk Place, London, United Kingdom
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de Oliveira Mendes-Aguiar C, do Monte Alves M, de Albuquerque Lopes Machado A, de Góis Monteiro GR, Medeiros IM, Queiroz JW, Lima ID, Pearson RD, Wilson ME, Glesby MJ, do Nascimento ELT, Jerônimo SMB. T-cell activation, senescence, and exhaustion in asymptomatic HIV/Leish mania infantum co-infection. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.03.06.23286828. [PMID: 36945413 PMCID: PMC10029033 DOI: 10.1101/2023.03.06.23286828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
Abstract
Background Leishmania infantum is an opportunistic parasitic infection. An immunocompromised state increases the risk of converting asymptomatic infection to symptomatic visceral leishmaniasis (VL), which has a ~5% fatality rate even with treatment. HIV coinfection increases the risk of death from VL. Methods A cross-sectional study was performed between 2014 and 2016 to determine the prevalence of L. infantum infection in HIV positive subjects residing in the state of Rio Grande do Norte, Brazil (n=1,372) and of these a subgroup of subjects were followed longitudinally. Subsequent incident cases of VL were ascertained from a public health database through 2018. A subgroup (n=69) of the cross-sectional study subjects was chosen to assess immune status (T cell activation, senescence, exhaustion) and outcome. The data were compared between asymptomatic HIV+/L. infantum+ (HIV/Leish), symptomatic visceral leishmaniasis (VL), recovered VL, DTH+ (Delayed-Type Hypersensitivity response - Leishmanin skin test), AIDS/VL, HIV+ only (HIV+), and Non-HIV/Non L. infantum infection (control subjects). Results The cross-sectional study showed 24.2% of HIV+ subjects had positive anti-IgG Leishmania antibodies. After 3 years, 2.4% (8 of 333) of these HIV/Leish coinfected subjects developed AIDS/VL, whereas 1.05% (11 of 1,039) of HIV subjects with negative leishmania serology developed AIDS/VL. Poor adherence to antiretroviral therapy (p=0.0008) or prior opportunistic infections (p=0.0007) was associated with development of AIDS/VL. CD4+ (p=0.29) and CD8+ (p=0.38) T cells counts or viral load (p=0.34) were similar between asymptomatic HIV/Leish and HIV subjects. However, activated CD8+CD38+HLA-DR+ T cells were higher in asymptomatic HIV/Leish than HIV group. Likewise, senescent (CD57+) or exhausted (PD1+) CD8+ T cells were higher in asymptomatic HIV/Leish than in AIDS/VL or HIV groups. Conclusion Although asymptomatic HIV/Leish subjects had normal and similar CD4+ and CD8+ T cells counts, their CD8+T cells had increased activation, senescence, and exhaustion, which could contribute to risk of developing VL.
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Affiliation(s)
| | - Manoella do Monte Alves
- Institute of Tropical Medicine of Rio Grande do Norte, Federal University of Rio Grande do Norte, Natal, RN, Brazil
- Department of Infectious Disease, Health Science Center, Federal University of Rio Grande do Norte, Natal, RN, Brazil
- Health Graduate Program, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | | | | | - Iara Marques Medeiros
- Institute of Tropical Medicine of Rio Grande do Norte, Federal University of Rio Grande do Norte, Natal, RN, Brazil
- Department of Infectious Disease, Health Science Center, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - Jose Wilton Queiroz
- Institute of Tropical Medicine of Rio Grande do Norte, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - Iraci Duarte Lima
- Institute of Tropical Medicine of Rio Grande do Norte, Federal University of Rio Grande do Norte, Natal, RN, Brazil
- State of Rio Grande do Norte Health Secretariat, Natal, RN, Brazil
| | - Richard D. Pearson
- Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, Charlottesville, VA, USA
| | - Mary E. Wilson
- Departments of Internal Medicine and Microbiology & Immunology, University of Iowa and the Veterans’ Affairs Medical Center, Iowa City, IA, USA
| | - Marshall J. Glesby
- Division of Infectious Disease, Weill Cornell Medical College, New York, NY, USA
| | - Eliana Lúcia Tomaz do Nascimento
- Institute of Tropical Medicine of Rio Grande do Norte, Federal University of Rio Grande do Norte, Natal, RN, Brazil
- Department of Infectious Disease, Health Science Center, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - Selma Maria Bezerra Jerônimo
- Institute of Tropical Medicine of Rio Grande do Norte, Federal University of Rio Grande do Norte, Natal, RN, Brazil
- Institute of Science and Technology of Tropical Diseases, Natal, RN, Brazil
- Department of Biochemistry, Federal University of Rio Grande do Norte, Natal, RN, Brazil
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Pilotte N, Thomas T, Zulch MF, Sirois AR, Minetti C, Reimer LJ, Williams SA, Saunders LJ. Targeting a highly repetitive genomic sequence for sensitive and specific molecular detection of the filarial parasite Mansonella perstans from human blood and mosquitoes. PLoS Negl Trop Dis 2022; 16:e0010615. [PMID: 36580452 PMCID: PMC9833530 DOI: 10.1371/journal.pntd.0010615] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 01/11/2023] [Accepted: 12/15/2022] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Mansonella perstans is among the most neglected of the neglected tropical diseases and is believed to cause more human infections than any other filarial pathogen in Africa. Based largely upon assumptions of limited infection-associated morbidity, this pathogen remains understudied, and many basic questions pertaining to its pathogenicity, distribution, prevalence, and vector-host relationships remain unanswered. However, in recent years, mounting evidence of the potential for increased Mansonella infection-associated disease has sparked a renewal in research interest. This, in turn, has produced a need for improved diagnostics, capable of providing more accurate pictures of infection prevalence, pathogen distribution, and vector-host interactions. METHODOLOGY/PRINCIPAL FINDINGS Utilizing a previously described pipeline for the discovery of optimal molecular diagnostic targets, we identified a repetitive DNA sequence, and developed a corresponding assay, which allows for the sensitive and species-specific identification of M. perstans in human blood samples. Testing also demonstrated the ability to utilize this assay for the detection of M. perstans in field-collected mosquito samples. When testing both sample types, our repeat-targeting index assay outperformed a ribosomal sequence-targeting reference assay, facilitating the identification of additional M. perstans-positive samples falsely characterized as "negative" using the less sensitive detection method. CONCLUSIONS/SIGNIFICANCE Through the development of an assay based upon the systematic identification of an optimal DNA target sequence, our novel diagnostic assay will provide programmatic efforts with a sensitive and specific testing platform that is capable of accurately mapping M. perstans infection and determining prevalence. Furthermore, with the added ability to identify the presence of M. perstans in mosquito samples, this assay will help to define our knowledge of the relationships that exist between this pathogen and the various geographically relevant mosquito species, which have been surmised to represent potential secondary vectors under certain conditions. Detection of M. perstans in mosquitoes will also demonstrate proof-of-concept for the mosquito-based monitoring of filarial pathogens not vectored primarily by mosquitoes, an approach expanding opportunities for integrated surveillance.
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Affiliation(s)
- Nils Pilotte
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, United States of America
- Department of Biological Sciences, Quinnipiac University, Hamden, Connecticut, United States of America
| | - Tamara Thomas
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, United States of America
| | - Michael F. Zulch
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, United States of America
| | - Allison R. Sirois
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, United States of America
| | - Corrado Minetti
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Lisa J. Reimer
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Steven A. Williams
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, United States of America
- Molecular and Cellular Biology Program, University of Massachusetts, Amherst, Massachusetts, United States of America
| | - Lori J. Saunders
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, United States of America
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Adu Mensah D, Debrah LB, Gyamfi PA, Rahamani AA, Opoku VS, Boateng J, Obeng P, Osei-Mensah J, Kroidl I, Klarmann-Schulz U, Hoerauf A, Debrah AY. Occurrence of Lymphatic Filariasis infection after 15 years of mass drug administration in two hotspot districts in the Upper East Region of Ghana. PLoS Negl Trop Dis 2022; 16:e0010129. [PMID: 35926012 PMCID: PMC9380951 DOI: 10.1371/journal.pntd.0010129] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 08/16/2022] [Accepted: 07/14/2022] [Indexed: 11/30/2022] Open
Abstract
Background Lymphatic filariasis (LF) causes chronic morbidity, which usually manifests as lymphedema or hydrocele. Mass drug administration (MDA) began in Kassena Nankana East Municipal (KNEM) and Nabdam, two hotspot districts in the Upper East Region in Ghana, in 2000 and 2005, respectively. This cross-sectional study evaluated the impact of 15 years of MDA on the control of LF as determined by circulating filarial antigen (CFA) and microfilariae assessment in the KNEM and the Nabdam districts. Methodology/Principal findings A total of 7,453 participants from eight sub-districts in the two hotspot districts (KNEM: N = 4604; Nabdam: N = 2849) were recruited into the study. The overall CFA prevalence as determined by the FTS was 19.6% and 12.8% in the KNEM and Nabdam districts, respectively. Manyoro, a sub-district on the border with Burkina Faso, recorded the highest CFA prevalence of 26% in the KNEM. Assessment of microfilariae and Og4C3 antigen was done from 1009 (KNEM: N = 799 (79.2%); Nabdam: N = 210 (20.8%)) randomly selected FTS-positive (N = 885) and FTS-negative (N = 124) individuals. The Og4C3 antigen was found in 22.6%/23.0% of the selected individuals (KNEM/Nabdam), whereas the night blood revealed microfilariae in only 0.7%/0.5%. Conclusions/Significance Using the WHO endorsed FTS, CFA prevalence exceeded the long-standing <2% threshold—which may need revision and validation. Surprisingly, the Og4C3 ELISA showed positive results in only about one-fifth of the FTS positive samples. However, even this result would not have met the <2% CFA criteria for LF elimination. In contrast, projections from the microfilariae results revealed a halt in LF transmission. The global elimination target was due in 2020 but has been extended to 2030 since this could not be met. Focused MDA intervention intensification on seasonal migrants and non-compliers, and implementation of alternative treatment strategies may suffice for the elimination of the disease. Lymphatic filariasis (LF) is a major neglected tropical disease (NTD) affecting over 120 million individuals worldwide and identified as one of WHO’s 20 NTDs targeted for elimination. It has strong links with poverty and is associated with significant clinical morbidity, which impose considerable socio-psychological and economic burdens on the affected individuals. One of the main goals of the Global Programme to Eliminate Lymphatic Filariasis (GPELF) is the use of mass drug administration (MDA) to interrupt LF transmission. The initial 2020 elimination target year set by the GPELF could not be met, with 2030 now the new proposed year targeted for global elimination. The study evaluated the impact of 15 years of MDA on the control of LF in two hotspot districts in Ghana. The results from this study are indicative of a halt in LF transmission in the districts, with microfilaria detected in <1% of those sampled. However, the antigenemia prevalence is still above the recommended level. MDA should be intensified especially at the border towns or alternative treatment strategies should be employed to finally eliminate the disease as some people who are still with the active infection can serve as a reservoir for recrudescence and transmission in already “LF-free” areas.
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Affiliation(s)
- Derrick Adu Mensah
- Department of Clinical Microbiology, School of Medicine and Dentistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
- Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Linda Batsa Debrah
- Department of Clinical Microbiology, School of Medicine and Dentistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
- Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Peter Akosah Gyamfi
- Department of Clinical Microbiology, School of Medicine and Dentistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
- Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
- Faculty of Health Sciences, Garden City University College, Kumasi, Ghana
| | - Abu Abudu Rahamani
- Department of Clinical Microbiology, School of Medicine and Dentistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
- Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Vera Serwaa Opoku
- Department of Clinical Microbiology, School of Medicine and Dentistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
- Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - John Boateng
- Department of Clinical Microbiology, School of Medicine and Dentistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
- Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Prince Obeng
- Department of Clinical Microbiology, School of Medicine and Dentistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
- Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Jubin Osei-Mensah
- Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Inge Kroidl
- Division of Infectious Diseases and Tropical Medicine, Medical Center of the University of Munich (LMU), Munich, Germany
- German Center for Infection Research (DZIF), Munich, Germany
| | - Ute Klarmann-Schulz
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
- German Center for Infection Research (DZIF), Bonn-Cologne, Germany
| | - Achim Hoerauf
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
- German Center for Infection Research (DZIF), Bonn-Cologne, Germany
| | - Alexander Yaw Debrah
- Faculty of Allied Health Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
- * E-mail:
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Bancroft D, Power GM, Jones RT, Massad E, Iriat JB, Preet R, Kinsman J, Logan JG. Vector control strategies in Brazil: a qualitative investigation into community knowledge, attitudes and perceptions following the 2015-2016 Zika virus epidemic. BMJ Open 2022; 12:e050991. [PMID: 35105618 PMCID: PMC8808399 DOI: 10.1136/bmjopen-2021-050991] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
OBJECTIVE The World Health Organization declared a Public Health Emergency of International Concern following the rapid emergence of neonatal microcephaly in Brazil during the 2015-2016 Zika virus (ZIKV) epidemic. In response, a national campaign sought to control Aedes mosquito populations and reduce ZIKV transmission. Achieving adherence to vector control or mosquito-bite reduction behaviours, including the use of topical mosquito repellents, is challenging. Coproduction of research at the community level is needed to understand and mitigate social determinants of lower engagement with Aedes preventive measures, particularly within disempowered groups. DESIGN In 2017, the Zika Preparedness Latin America Network (ZikaPLAN) conducted a qualitative study to understand individual and community level experiences of ZIKV and other mosquito-borne disease outbreaks. Presented here is a thematic analysis of 33 transcripts from community focus groups and semistructured interviews, applying the Health Belief Model (HBM) to elaborate knowledge, attitudes and perceptions of ZIKV and vector control strategies. PARTICIPANTS 120 purposively sampled adults of approximate reproductive age (18-45); 103 women participated in focus groups and 17 men in semistructured interviews. SETTING Two sociopolitically and epidemiologically distinct cities in Brazil: Jundiaí (57 km north of São Paolo) and Salvador (Bahia state capital). RESULTS Four key and 12 major themes emerged from the analysis: (1) knowledge and cues to action; (2) attitudes and normative beliefs (perceived threat, barriers, benefits and self-efficacy); (3) behaviour change (household prevention and community participation); and (4) community preferences for novel repellent tools, vector control strategies and ZIKV messaging. CONCLUSIONS Common barriers to repellent adherence were accessibility, appearance and effectiveness. A strong case is made for the transferability of the HBM to inform epidemic preparedness for mosquito-borne disease outbreaks at the community level. Nationally, a health campaign targeting men is recommended, in addition to local mobilisation of funding to strengthen surveillance, risk communication and community engagement.
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Affiliation(s)
- Dani Bancroft
- Department of Public Health, Environments and Society, London School of Hygiene and Tropical Medicine, London, UK
| | - Grace M Power
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London, UK
| | - Robert T Jones
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London, UK
| | - Eduardo Massad
- School of Medicine, University of São Paulo, São Paulo, SP, Brazil
- School of Applied Mathematics, Fundação Getulio Vargas, Rio de Janeiro, RJ, Brazil
| | | | - Raman Preet
- Department of Epidemiology and Global Health, Umeå University, Umeå, Sweden
| | - John Kinsman
- Department of Epidemiology and Global Health, Umeå University, Umeå, Sweden
| | - James G Logan
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London, UK
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11
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Stewart-Ibarra AM, Rollock L, Best S, Brown T, Diaz AR, Dunbar W, Lippi CA, Mahon R, Ryan SJ, Trotman A, Van Meerbeeck CJ, Lowe R. Co-learning during the co-creation of a dengue early warning system for the health sector in Barbados. BMJ Glob Health 2022; 7:bmjgh-2021-007842. [PMID: 34992079 PMCID: PMC8739055 DOI: 10.1136/bmjgh-2021-007842] [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: 10/27/2021] [Accepted: 12/03/2021] [Indexed: 11/15/2022] Open
Abstract
Over the past decade, the Caribbean region has been challenged by compound climate and health hazards, including tropical storms, extreme heat and droughts and overlapping epidemics of mosquito-borne diseases, including dengue, chikungunya and Zika. Early warning systems (EWS) are a key climate change adaptation strategy for the health sector. An EWS can integrate climate information in forecasting models to predict the risk of disease outbreaks several weeks or months in advance. In this article, we share our experiences of co-learning during the process of co-creating a dengue EWS for the health sector in Barbados, and we discuss barriers to implementation as well as key opportunities. This process has involved bringing together health and climate practitioners with transdisciplinary researchers to jointly identify needs and priorities, assess available data, co-create an early warning tool, gather feedback via national and regional consultations and conduct trainings. Implementation is ongoing and our team continues to be committed to a long-term process of collaboration. Developing strong partnerships, particularly between the climate and health sectors in Barbados, has been a critical part of the research and development. In many countries, the national climate and health sectors have not worked together in a sustained or formal manner. This collaborative process has purposefully pushed us out of our comfort zone, challenging us to venture beyond our institutional and disciplinary silos. Through the co-creation of the EWS, we anticipate that the Barbados health system will be better able to mainstream climate information into decision-making processes using tailored tools, such as epidemic forecast reports, risk maps and climate-health bulletins, ultimately increasing the resilience of the health system.
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Affiliation(s)
| | | | - Sabu Best
- Barbados Meteorological Services, Christ Church, Barbados
| | - Tia Brown
- Barbados Meteorological Services, Christ Church, Barbados
| | - Avriel R Diaz
- International Research Institute for Climate and Society (IRI), Columbia University's Climate School, New York, New York, USA
| | - Willy Dunbar
- Department of Health Promotion and Disease Prevention, Florida International University, Miami, Florida, USA
| | - Catherine A Lippi
- Department of Geography and Emerging Pathogens Institute, University of Florida, Gainesville, Florida, USA
| | - Roché Mahon
- Caribbean Institute for Meteorology and Hydrology, Bridgetown, Parish of Saint Michael, Barbados
| | - Sadie J Ryan
- Department of Geography and Emerging Pathogens Institute, University of Florida, Gainesville, Florida, USA
| | - Adrian Trotman
- Caribbean Institute for Meteorology and Hydrology, Bridgetown, Parish of Saint Michael, Barbados
| | - Cedric J Van Meerbeeck
- Caribbean Institute for Meteorology and Hydrology, Bridgetown, Parish of Saint Michael, Barbados
| | - Rachel Lowe
- Centre on Climate Change & Planetary Health and Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, UK.,Earth Sciences Department, Barcelona Supercomputing Center, Barcelona, Spain.,Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain
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12
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Adhikari R, Acharya D, Wagle A. Sociodemographic characteristics as predictors of knowledge regarding mode of transmission of Lymphatic Filariasis among population of Nepal. PLOS GLOBAL PUBLIC HEALTH 2022; 2:e0000082. [PMID: 36962552 PMCID: PMC10022298 DOI: 10.1371/journal.pgph.0000082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 09/19/2022] [Indexed: 03/26/2023]
Abstract
INTRODUCTION The majority of the districts of Nepal (63 out of 77) were detected as prevalent of Lymphatic Filariasis (LF), with an average prevalence of 13 percent ranging from less than one to 39 percent in Nepal. Despite people's ignorance about the LF, the government has a target to eliminate LF by 2020. The study aimed to assess the association between sociodemographic characteristics and knowledge of the mode of transmission of LF. MATERIALS AND METHODS The study used a cross-sectional design. Secondary data from Nepal Demographic and Health Survey 2016 were analysed. Altogether, 11040 participants participated in the study. Sociodemographic characteristics were the independent variables, whereas household heads' knowledge of LF transmission was the dependent variable. Descriptive, bivariate, and multivariate analyses were performed to assess the association between sociodemographic characteristics and knowledge of the mode of transmission. RESULTS Findings showed that only 28 percent of household-heads correctly identified the mode of transmission of Lymphatic Filariasis in the study. Household head's age, sex, wealth status, place of residence in terms of areas, geo-belt and province, migration history, and household assets such as bed nets, Radio, TV were significantly associated with the knowledge of the mode of transmission of Lymphatic Filariasis. Variables: wealth status, sex, residence, eco-belts, possessing bed nets, and Radio appeared as significant predictors for knowledge of the mode of transmission of Lymphatic Filariasis. The richest to the poorest people had lower odds ranging from 0.22 to 0.53 for knowing the mode of transmission of Lymphatic Filariasis compared to the richest people (p = 0.001). CONCLUSION The study identified the population groups with a low level of knowledge of modes of transmission of Lymphatic Filariasis. Thus, it can be inferred from the study that relevant programs need to focus on women, people residing in the mountains and Terai, and those belonging to the middle and poor wealth index. The study also emphasizes that information, education, and communication materials can effectively impart knowledge of Lymphatic Filariasis.
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Affiliation(s)
- Ramesh Adhikari
- Mahendra Ratna Campus [Tribhuvan University], Kathmandu, Nepal
- Center for Research on Education, Health and Social Science (CREHSS), Kathmandu, Nepal
| | - Devaraj Acharya
- Bhairahawa Multiple Campus [Tribhuvan University], Rupandehi, Nepal
| | - Aakriti Wagle
- Center for Research on Education, Health and Social Science (CREHSS), Kathmandu, Nepal
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13
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Prada JM, Davis EL, Touloupou P, Stolk WA, Kontoroupis P, Smith ME, Sharma S, Michael E, de Vlas SJ, Hollingsworth TD. Elimination or Resurgence: Modelling Lymphatic Filariasis After Reaching the 1% Microfilaremia Prevalence Threshold. J Infect Dis 2020; 221:S503-S509. [PMID: 31853554 PMCID: PMC7289550 DOI: 10.1093/infdis/jiz647] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The low prevalence levels associated with lymphatic filariasis elimination pose a challenge for effective disease surveillance. As more countries achieve the World Health Organization criteria for halting mass treatment and move on to surveillance, there is increasing reliance on the utility of transmission assessment surveys (TAS) to measure success. However, the long-term disease outcomes after passing TAS are largely untested. Using 3 well-established mathematical models, we show that low-level prevalence can be maintained for a long period after halting mass treatment and that true elimination (0% prevalence) is usually slow to achieve. The risk of resurgence after achieving current targets is low and is hard to predict using just current prevalence. Although resurgence is often quick (<5 years), it can still occur outside of the currently recommended postintervention surveillance period of 4-6 years. Our results highlight the need for ongoing and enhanced postintervention monitoring, beyond the scope of TAS, to ensure sustained success.
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Affiliation(s)
- Joaquin M Prada
- School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK
| | - Emma L Davis
- Zeeman Institute for Systems Biology and Infectious Disease Epidemiology Research, Mathematics Institute and School of Life Sciences, University of Warwick, Coventry, UK
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Headington, Oxford, UK
| | | | - Wilma A Stolk
- Department of Public Health, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Periklis Kontoroupis
- Department of Public Health, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Morgan E Smith
- Department of Biological Sciences, University of Notre Dame, South Bend, Indiana, USA
| | - Swarnali Sharma
- Department of Biological Sciences, University of Notre Dame, South Bend, Indiana, USA
| | - Edwin Michael
- Department of Biological Sciences, University of Notre Dame, South Bend, Indiana, USA
| | - Sake J de Vlas
- Department of Public Health, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - T Déirdre Hollingsworth
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Headington, Oxford, UK
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14
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Burgert-Brucker CR, Zoerhoff KL, Headland M, Shoemaker EA, Stelmach R, Karim MJ, Batcho W, Bougouma C, Bougma R, Benjamin Didier B, Georges N, Marfo B, Lemoine JF, Pangaribuan HU, Wijayanti E, Coulibaly YI, Doumbia SS, Rimal P, Salissou AB, Bah Y, Mwingira U, Nshala A, Muheki E, Shott J, Yevstigneyeva V, Ndayishimye E, Baker M, Kraemer J, Brady M. Risk factors associated with failing pre-transmission assessment surveys (pre-TAS) in lymphatic filariasis elimination programs: Results of a multi-country analysis. PLoS Negl Trop Dis 2020; 14:e0008301. [PMID: 32479495 PMCID: PMC7289444 DOI: 10.1371/journal.pntd.0008301] [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: 11/08/2019] [Revised: 06/11/2020] [Accepted: 04/16/2020] [Indexed: 11/20/2022] Open
Abstract
Achieving elimination of lymphatic filariasis (LF) as a public health problem requires a minimum of five effective rounds of mass drug administration (MDA) and demonstrating low prevalence in subsequent assessments. The first assessments recommended by the World Health Organization (WHO) are sentinel and spot-check sites—referred to as pre-transmission assessment surveys (pre-TAS)—in each implementation unit after MDA. If pre-TAS shows that prevalence in each site has been lowered to less than 1% microfilaremia or less than 2% antigenemia, the implementation unit conducts a TAS to determine whether MDA can be stopped. Failure to pass pre-TAS means that further rounds of MDA are required. This study aims to understand factors influencing pre-TAS results using existing programmatic data from 554 implementation units, of which 74 (13%) failed, in 13 countries. Secondary data analysis was completed using existing data from Bangladesh, Benin, Burkina Faso, Cameroon, Ghana, Haiti, Indonesia, Mali, Nepal, Niger, Sierra Leone, Tanzania, and Uganda. Additional covariate data were obtained from spatial raster data sets. Bivariate analysis and multilinear regression were performed to establish potential relationships between variables and the pre-TAS result. Higher baseline prevalence and lower elevation were significant in the regression model. Variables statistically significantly associated with failure (p-value ≤0.05) in the bivariate analyses included baseline prevalence at or above 5% or 10%, use of Filariasis Test Strips (FTS), primary vector of Culex, treatment with diethylcarbamazine-albendazole, higher elevation, higher population density, higher enhanced vegetation index (EVI), higher annual rainfall, and 6 or more rounds of MDA. This paper reports for the first time factors associated with pre-TAS results from a multi-country analysis. This information can help countries more effectively forecast program activities, such as the potential need for more rounds of MDA, and prioritize resources to ensure adequate coverage of all persons in areas at highest risk of failing pre-TAS. Achieving elimination of lymphatic filariasis (LF) as a public health problem requires a minimum of five rounds of mass drug administration (MDA) and being able to demonstrate low prevalence in several subsequent assessments. LF elimination programs implement sentinel and spot-check site assessments, called pre-TAS, to determine whether districts are eligible to implement more rigorous population-based surveys to determine whether MDA can be stopped or if further rounds are required. Reasons for failing pre-TAS are not well understood and have not previously been examined with data compiled from multiple countries. For this analysis, we analyzed data from routine USAID and WHO reports from Bangladesh, Benin, Burkina Faso, Cameroon, Ghana, Haiti, Indonesia, Mali, Nepal, Niger, Sierra Leone, Tanzania, and Uganda. In a model that included multiple variables, high baseline prevalence and lower elevation were significant. In models comparing only one variable to the outcome, the following were statistically significantly associated with failure: higher baseline prevalence at or above 5% or 10%, use of the FTS, primary vector of Culex, treatment with diethylcarbamazine-albendazole, lower elevation, higher population density, higher Enhanced Vegetation Index, higher annual rainfall, and six or more rounds of mass drug administration. These results can help national programs plan MDA more effectively, e.g., by focusing resources on areas with higher baseline prevalence and/or lower elevation.
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Affiliation(s)
| | - Kathryn L. Zoerhoff
- Global Health Division, RTI International, Washington, DC, United States of America
| | - Maureen Headland
- Global Health Division, RTI International, Washington, DC, United States of America
- Global Health, Population, and Nutrition, FHI 360, Washington, DC, United States of America
| | - Erica A. Shoemaker
- Global Health Division, RTI International, Washington, DC, United States of America
| | - Rachel Stelmach
- Global Health Division, RTI International, Washington, DC, United States of America
| | | | - Wilfrid Batcho
- National Control Program of Communicable Diseases, Ministry of Health, Cotonou, Benin
| | - Clarisse Bougouma
- Lymphatic Filariasis Elimination Program, Ministère de la Santé, Ouagadougou, Burkina Faso
| | - Roland Bougma
- Lymphatic Filariasis Elimination Program, Ministère de la Santé, Ouagadougou, Burkina Faso
| | - Biholong Benjamin Didier
- National Onchocerciasis and Lymphatic Filariasis Control Program, Ministry of Health, Yaounde, Cameroon
| | - Nko'Ayissi Georges
- National Onchocerciasis and Lymphatic Filariasis Control Program, Ministry of Health, Yaounde, Cameroon
| | - Benjamin Marfo
- Neglected Tropical Diseases Programme, Ghana Health Service, Accra, Ghana
| | | | | | - Eksi Wijayanti
- National Institute Health Research & Development, Ministry of Health, Jakarta, Indonesia
| | - Yaya Ibrahim Coulibaly
- Filariasis Unit, International Center of Excellence in Research, Faculty of Medicine and Odontostomatology, Bamako, Mali
| | - Salif Seriba Doumbia
- Filariasis Unit, International Center of Excellence in Research, Faculty of Medicine and Odontostomatology, Bamako, Mali
| | - Pradip Rimal
- Epidemiology and Disease Control Division, Department of Health Service, Kathmandu, Nepal
| | | | - Yukaba Bah
- National Neglected Tropical Disease Program, Ministry of Health and Sanitation, Freetown, Sierra Leone
| | - Upendo Mwingira
- Neglected Tropical Disease Control Programme, National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Andreas Nshala
- IMA World Health/Tanzania NTD Control Programme, Uppsala University, & TIBA Fellow, Dar es Salaam, Tanzania
| | - Edridah Muheki
- Programme to Eliminate Lymphatic Filariasis, Ministry of Health, Kampala, Uganda
| | - Joseph Shott
- Division of Neglected Tropical Diseases, Office of Infectious Diseases, Bureau for Global Health, USAID, Washington, DC, United States of America
| | - Violetta Yevstigneyeva
- Division of Neglected Tropical Diseases, Office of Infectious Diseases, Bureau for Global Health, USAID, Washington, DC, United States of America
| | - Egide Ndayishimye
- Global Health, Population, and Nutrition, FHI 360, Washington, DC, United States of America
| | - Margaret Baker
- Global Health Division, RTI International, Washington, DC, United States of America
| | - John Kraemer
- Global Health Division, RTI International, Washington, DC, United States of America
- Georgetown University, Washington, DC, United States of America
| | - Molly Brady
- Global Health Division, RTI International, Washington, DC, United States of America
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15
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Yokoly FN, Zahouli JBZ, Méite A, Opoku M, Kouassi BL, de Souza DK, Bockarie M, Koudou BG. Low transmission of Wuchereria bancrofti in cross-border districts of Côte d'Ivoire: A great step towards lymphatic filariasis elimination in West Africa. PLoS One 2020; 15:e0231541. [PMID: 32282840 PMCID: PMC7153895 DOI: 10.1371/journal.pone.0231541] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 03/25/2020] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Lymphatic filariasis (LF) is widely endemic in Côte d'Ivoire, and elimination as public health problem (EPHP) is based on annual mass drug administration (MDA) using ivermectin and albendazole. To guide EPHP efforts, we evaluated Wuchereria bancrofti infection indices among humans, and mosquito vectors after four rounds of MDA in four cross-border health districts of Côte d'Ivoire. METHODOLOGY We monitored people and mosquitoes for W. bancrofti infections in the cross-border health districts of Aboisso, Bloléquin, Odienné and Ouangolodougou, Côte d'Ivoire. W. bancrofti circulating filarial antigen (CFA) was identified using filariasis test strips, and antigen-positive individuals were screened for microfilaremia. Moreover, filarial mosquito vectors were sampled using window exit traps and pyrethrum sprays, and identified morphologically at species level. Anopheles gambiae s.l. and Culex quinquefasciatus females were analyzed for W. bancrofti infection using polymerase chain reaction (PCR) technique. PRINCIPAL FINDINGS Overall, we found a substantial decline in W. bancrofti infection indices after four rounds of MDA compared to pre-MDA baseline data. CFA prevalence fell from 3.38-5.50% during pre-MDA to 0.00-1.53% after MDA interventions. No subjects had detectable levels of CFA in Ouangolodougou. Moreover, post-MDA CFA prevalence was very low, and below the 1% elimination threshold in Aboisso (0.19%) and Odienné (0.49%). Conversely, CFA prevalence remained above 1% in Bloléquin (1.53%). W. bancrofti microfilariae (Mf) were not found in Aboisso, Bloléquin, and Ouangolodougou, except for Odienné with low prevalence (0.16%; n = 613) and microfilaremia of 32.0 Mf/mL. No An. gambiae s.l. and Cx. quinquefasciatus pools were infected with W. bancrofti in Bloléquin and Ouangolodougou, while they exhibited low infection rates in Aboisso (1% and 0.07%), and Odienné (0.08% and 0.08%), respectively. CONCLUSIONS In cross-border areas of Côte d'Ivoire, LF infection indices in humans and mosquito vectors substantially declined after four rounds of MDA. CFA prevalence fell under the World Health Organization (WHO)-established threshold (1%) in Aboisso, Ouangolodougou and Odienné. Moreover, W. bancrofti prevalence in mosquitoes was lower than WHO-established threshold (2%) in all areas. This might suggest the interruption of W. bancrofti transmission, and possible MDA cessation. However, a formal transmission assessment survey (TAS) and molecular xenomonitoring in mosquito vectors should be implemented before eventual MDA cessation. However, MDA should pursue in Bloléquin where W. bancrofti infection prevalence remained above 1%. Our results provided important ramifications for LF control efforts towards EPHP in Côte d'Ivoire.
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Affiliation(s)
- Firmain N. Yokoly
- Unité de Formation et de Recherche Sciences de la Nature, Université Nangui Abrogoua, Abidjan, Côte d’Ivoire
- Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Abidjan, Côte d’Ivoire
| | - Julien B. Z. Zahouli
- Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Abidjan, Côte d’Ivoire
- Centre d’Entomologie Médicale et Vétérinaire, Université Alassane Ouattara, Bouaké, Côte d’Ivoire
| | - Aboulaye Méite
- Programme National de Lutte contre les Maladies Tropicales Négligées à Chimiothérapie Préventive, Ministère de la Santé, Abidjan, Côte d’Ivoire
| | - Millicent Opoku
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Accra, Ghana
- European & Developing Countries Clinical Trials Partnership, Cape Town, South Africa
| | - Bernard L. Kouassi
- Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Abidjan, Côte d’Ivoire
| | - Dziedzom K. de Souza
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Accra, Ghana
| | - Moses Bockarie
- European & Developing Countries Clinical Trials Partnership, Cape Town, South Africa
- Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Benjamin G. Koudou
- Unité de Formation et de Recherche Sciences de la Nature, Université Nangui Abrogoua, Abidjan, Côte d’Ivoire
- Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Abidjan, Côte d’Ivoire
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16
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Minetti C, Pilotte N, Zulch M, Canelas T, Tettevi EJ, Veriegh FBD, Osei-Atweneboana MY, Williams SA, Reimer LJ. Field evaluation of DNA detection of human filarial and malaria parasites using mosquito excreta/feces. PLoS Negl Trop Dis 2020; 14:e0008175. [PMID: 32267840 PMCID: PMC7170280 DOI: 10.1371/journal.pntd.0008175] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 04/20/2020] [Accepted: 02/27/2020] [Indexed: 12/02/2022] Open
Abstract
We recently developed a superhydrophobic cone-based method for the collection of mosquito excreta/feces (E/F) for the molecular xenomonitoring of vector-borne parasites showing higher throughput compared to the traditional approach. To test its field applicability, we used this platform to detect the presence of filarial and malaria parasites in two villages of Ghana and compared results to those for detection in mosquito carcasses and human blood. We compared the molecular detection of three parasites (Wuchereria bancrofti, Plasmodium falciparum and Mansonella perstans) in mosquito E/F, mosquito carcasses and human blood collected from the same households in two villages in the Savannah Region of the country. We successfully detected the parasite DNA in mosquito E/F from indoor resting mosquitoes, including W. bancrofti which had a very low community prevalence (2.5-3.8%). Detection in the E/F samples was concordant with detection in insect whole carcasses and human blood, and a parasite not vectored by mosquitoes was detected as well.Our approach to collect and test mosquito E/F successfully detected a variety of parasites at varying prevalence in the human population under field conditions, including a pathogen (M. perstans) which is not transmitted by mosquitoes. The method shows promise for further development and applicability for the early detection and surveillance of a variety of pathogens carried in human blood.
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Affiliation(s)
- Corrado Minetti
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Nils Pilotte
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, United States of America
- Molecular and Cellular Biology Program, University of Massachusetts, Amherst, Massachusetts, United States of America
| | - Michael Zulch
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, United States of America
| | - Tiago Canelas
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Edward J. Tettevi
- Biomedical and Public Health Research Unit, CSIR-Water Research Institute, Council for Scientific and Industrial Research, Accra, Ghana
| | - Francis B. D. Veriegh
- Biomedical and Public Health Research Unit, CSIR-Water Research Institute, Council for Scientific and Industrial Research, Accra, Ghana
| | - Mike Yaw Osei-Atweneboana
- Biomedical and Public Health Research Unit, CSIR-Water Research Institute, Council for Scientific and Industrial Research, Accra, Ghana
| | - Steven A. Williams
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, United States of America
- Molecular and Cellular Biology Program, University of Massachusetts, Amherst, Massachusetts, United States of America
| | - Lisa J. Reimer
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
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17
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Graves PM, Sheridan S, Fuimaono S, Lau CL. Demographic, socioeconomic and disease knowledge factors, but not population mobility, associated with lymphatic filariasis infection in adult workers in American Samoa in 2014. Parasit Vectors 2020; 13:125. [PMID: 32164780 PMCID: PMC7068921 DOI: 10.1186/s13071-020-3996-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Accepted: 02/26/2020] [Indexed: 01/21/2023] Open
Abstract
Background Prevalence of lymphatic filariasis (LF) antigen in American Samoa was 16.5% in 1999. Seven rounds of mass drug administration (MDA) programmes between 2000 and 2006 reduced antigen prevalence to 2.3%. The most efficient methods of surveillance after MDA are not clear, but testing specific at-risk groups such as adults may provide earlier warning of resurgence. The role of migration from LF endemic countries in maintaining transmission also needs investigation. Few studies have investigated knowledge about LF and how that relates to infection risk. This study aims to investigate associations between socio-demographics, population mobility, disease knowledge and LF infection risk. Methods In 2014, we surveyed 670 adults aged 16–68 years (62% female) at two worksites in American Samoa. Sera were tested for LF antigen and antibodies (Bm14 and Wb123) by rapid test and/or ELISA. Multivariate logistic regression was used to assess association between seromarkers and demographic factors, household socioeconomic status (SES), residence, travel history, and knowledge of LF. Results Overall, 1.8% of participants were positive for antigen, 11.8% for Bm14, 11.3% for Wb123 and 17.3% for at least one antibody. Recent travel outside American Samoa was not associated with positivity for any seromarker. Men had higher seroprevalence than women for all outcomes (any antibody: adjusted odds ratio (aOR) = 3.49 (95% CI: 2.21–5.49). Those aged over 35 years (compared to 15–24 years) had higher prevalence of Bm14 antibody (aOR = 3.75, 3.76 and 4.17 for ages 35–44, 45–54 and ≥ 55 years, respectively, P < 0.05). Lower SES was associated with seropositivity (antigen: aOR = 2.89, 95% CI: 1.09–7.69; either antibody: aOR = 1.51, 95% CI: 1.12–2.05). Those who knew that mosquitoes transmitted LF had lower Wb123 antibody prevalence (aOR = 0.55, 95% CI: 0.32–0.95). Conclusions Opportunistic sampling of adults at worksites provided an efficient and representative way to assess prevalence and risk factors for LF in American Samoa and in hindsight, foreshadowed the resurgence of transmission. Risk of LF infection, detected by one or more serological markers, was not related to recent travel history, but was strongly associated with male gender, older age, lower SES, and lack of knowledge about mosquito transmission. These results could guide future efforts to increase MDA participation.![]()
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Affiliation(s)
- Patricia M Graves
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Cairns, QLD, Australia. .,Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD, Australia.
| | - Sarah Sheridan
- Department of Global Health, Research School of Population Health, The Australian National University, Canberra, Australia
| | - Saipale Fuimaono
- Department of Public Health, American Samoa Department of Health, Pago Pago, American Samoa
| | - Colleen L Lau
- Department of Global Health, Research School of Population Health, The Australian National University, Canberra, Australia
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18
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Fauver JR, Martin J, Weil GJ, Mitreva M, Fischer PU. De novo Assembly of the Brugia malayi Genome Using Long Reads from a Single MinION Flowcell. Sci Rep 2019; 9:19521. [PMID: 31863009 PMCID: PMC6925183 DOI: 10.1038/s41598-019-55908-y] [Citation(s) in RCA: 5] [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: 06/21/2019] [Accepted: 11/28/2019] [Indexed: 11/15/2022] Open
Abstract
Filarial nematode infections cause a substantial global disease burden. Genomic studies of filarial worms can improve our understanding of their biology and epidemiology. However, genomic information from field isolates is limited and available reference genomes are often discontinuous. Single molecule sequencing technologies can reduce the cost of genome sequencing and long reads produced from these devices can improve the contiguity and completeness of genome assemblies. In addition, these new technologies can make generation and analysis of large numbers of field isolates feasible. In this study, we assessed the performance of the Oxford Nanopore Technologies MinION for sequencing and assembling the genome of Brugia malayi, a human parasite widely used in filariasis research. Using data from a single MinION flowcell, a 90.3 Mb nuclear genome was assembled into 202 contigs with an N50 of 2.4 Mb. This assembly covered 96.9% of the well-defined B. malayi reference genome with 99.2% identity. The complete mitochondrial genome was obtained with individual reads and the nearly complete genome of the endosymbiotic bacteria Wolbachia was assembled alongside the nuclear genome. Long-read data from the MinION produced an assembly that approached the quality of a well-established reference genome using comparably fewer resources.
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Affiliation(s)
- Joseph R Fauver
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States.
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, United States.
| | - John Martin
- McDonnell Genome Institute, Washington University School of Medicine, St. Louis, MO, United States
| | - Gary J Weil
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
| | - Makedonka Mitreva
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
- McDonnell Genome Institute, Washington University School of Medicine, St. Louis, MO, United States
| | - Peter U Fischer
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
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19
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Davis EL, Reimer LJ, Pellis L, Hollingsworth TD. Evaluating the Evidence for Lymphatic Filariasis Elimination. Trends Parasitol 2019; 35:860-869. [PMID: 31506245 PMCID: PMC7413036 DOI: 10.1016/j.pt.2019.08.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 08/19/2019] [Accepted: 08/19/2019] [Indexed: 12/01/2022]
Abstract
In the global drive for elimination of lymphatic filariasis (LF), 15 countries have achieved validation of elimination as a public health problem (EPHP). Recent empirical evidence has demonstrated that EPHP does not always lead to elimination of transmission (EOT). Here we show how the probability of elimination explicitly depends on key biological parameters, many of which have been poorly characterized, leading to a poor evidence base for the elimination threshold. As more countries progress towards EPHP it is essential that this process is well-informed, as prematurely halting treatment and surveillance programs could pose a serious threat to global progress. We highlight that refinement of the weak empirical evidence base is vital to understand drivers of elimination and inform long-term policy.
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Affiliation(s)
| | - Lisa J Reimer
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Lorenzo Pellis
- University of Manchester, Oxford Road, Manchester M13 9PL, UK
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