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Kittichai V, Kaewthamasorn M, Samung Y, Jomtarak R, Naing KM, Tongloy T, Chuwongin S, Boonsang S. Automatic identification of medically important mosquitoes using embedded learning approach-based image-retrieval system. Sci Rep 2023; 13:10609. [PMID: 37391476 PMCID: PMC10313673 DOI: 10.1038/s41598-023-37574-3] [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: 01/05/2023] [Accepted: 06/23/2023] [Indexed: 07/02/2023] Open
Abstract
Mosquito-borne diseases such as dengue fever and malaria are the top 10 leading causes of death in low-income countries. Control measure for the mosquito population plays an essential role in the fight against the disease. Currently, several intervention strategies; chemical-, biological-, mechanical- and environmental methods remain under development and need further improvement in their effectiveness. Although, a conventional entomological surveillance, required a microscope and taxonomic key for identification by professionals, is a key strategy to evaluate the population growth of these mosquitoes, these techniques are tedious, time-consuming, labor-intensive, and reliant on skillful and well-trained personnel. Here, we proposed an automatic screening, namely the deep metric learning approach and its inference under the image-retrieval process with Euclidean distance-based similarity. We aimed to develop the optimized model to find suitable miners and suggested the robustness of the proposed model by evaluating it with unseen data under a 20-returned image system. During the model development, well-trained ResNet34 are outstanding and no performance difference when comparing five data miners that showed up to 98% in its precision even after testing the model with both image sources: stereomicroscope and mobile phone cameras. The robustness of the proposed-trained model was tested with secondary unseen data which showed different environmental factors such as lighting, image scales, background colors and zoom levels. Nevertheless, our proposed neural network still has great performance with greater than 95% for sensitivity and precision, respectively. Also, the area under the ROC curve given the learning system seems to be practical and empirical with its value greater than 0.960. The results of the study may be used by public health authorities to locate mosquito vectors nearby. If used in the field, our research tool in particular is believed to accurately represent a real-world scenario.
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Affiliation(s)
- Veerayuth Kittichai
- Faculty of Medicine, King Mongkut's Institute of Technology Ladkrabang, Bangkok, Thailand
| | - Morakot Kaewthamasorn
- Veterinary Parasitology Research Unit, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
| | - Yudthana Samung
- Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Rangsan Jomtarak
- Faculty of Science and Technology, Suan Dusit University, Bangkok, Thailand
| | - Kaung Myat Naing
- College of Advanced Manufacturing Innovation, King Mongkut's Institute of Technology Ladkrabang, Bangkok, Thailand
| | - Teerawat Tongloy
- College of Advanced Manufacturing Innovation, King Mongkut's Institute of Technology Ladkrabang, Bangkok, Thailand
| | - Santhad Chuwongin
- College of Advanced Manufacturing Innovation, King Mongkut's Institute of Technology Ladkrabang, Bangkok, Thailand
| | - Siridech Boonsang
- Department of Electrical Engineering, School of Engineering, King Mongkut's Institute of Technology Ladkrabang, Bangkok, Thailand.
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Mnkai J, Ritter M, Maganga L, Maboko L, Olomi W, Clowes P, Minich J, Lelo AE, Kariuki D, Debrah AY, Geldmacher C, Hoelscher M, Saathoff E, Chachage M, Pfarr K, Hoerauf A, Kroidl I. Increased HIV Incidence in Wuchereria bancrofti Microfilaria Positive Individuals in Tanzania. Pathogens 2023; 12:pathogens12030387. [PMID: 36986309 PMCID: PMC10054595 DOI: 10.3390/pathogens12030387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 02/23/2023] [Accepted: 02/24/2023] [Indexed: 03/05/2023] Open
Abstract
Background: Infections with Wuchereria bancrofti are associated with reduced immunity against concomitant infections. Indeed, our previous study described a 2.3-fold increased HIV incidence among individuals with W. bancrofti infection, as measured by the circulating filarial antigen of the adult worm. This new study aimed to retrospectively determine microfilariae status of the participants to assess if the previously described increased HIV susceptibility was associated with the presence of MF in the same cohort. Methods: CFA positive but HIV negative biobanked human blood samples (n = 350) were analyzed for W. bancrofti MF chitinase using real time PCR. Results: The PCR provided a positive signal in 12/350 (3.4%) samples. During four years of follow-up (1109 person years (PY)), 22 study participants acquired an HIV infection. In 39 PY of W. bancrofti MF chitinase positive individuals, three new HIV infections occurred (7.8 cases per 100 PY), in contrast to 19 seroconversions in 1070 PY of W. bancrofti MF chitinase negative individuals (1.8 cases per 100 PY, p = 0.014). Conclusions: In the subgroup of MF-producing Wb-infected individuals, the HIV incidence exceeded the previously described moderate increased risk for HIV seen in all Wb-infected individuals (regardless of MF status) compared with uninfected persons from the same area.
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Affiliation(s)
- Jonathan Mnkai
- National Institute of Medical Research (NIMR), Mbeya Medical Research Center (MMRC), Mbeya P.O. Box 2410, Tanzania
| | - Manuel Ritter
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn (UKB), 53127 Bonn, Germany
| | - Lucas Maganga
- National Institute of Medical Research (NIMR), Mbeya Medical Research Center (MMRC), Mbeya P.O. Box 2410, Tanzania
| | - Leonard Maboko
- National Institute of Medical Research (NIMR), Mbeya Medical Research Center (MMRC), Mbeya P.O. Box 2410, Tanzania
- Tanzania Commission for AIDS, Dodoma P.O. Box 2904, Tanzania
| | - Willyhelmina Olomi
- National Institute of Medical Research (NIMR), Mbeya Medical Research Center (MMRC), Mbeya P.O. Box 2410, Tanzania
| | - Petra Clowes
- National Institute of Medical Research (NIMR), Mbeya Medical Research Center (MMRC), Mbeya P.O. Box 2410, Tanzania
| | - Jessica Minich
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn (UKB), 53127 Bonn, Germany
| | - Agola Eric Lelo
- Kenya Medical Research Institute (KEMRI), KNH, Nairobi, Kenya
| | - Daniel Kariuki
- College of Health Sciences, Jomo Kenyatta University of Agriculture and Technology (JKUAT), Juja, Kenya
| | - Alexander Yaw Debrah
- Kumasi Centre for Collaborative Research (KCCR), Kwame Nkrumah University of Science and Technology, UPO, PMB, Kumasi, Ghana
| | - Christof Geldmacher
- Division of Infectious Diseases and Tropical Medicine, University Hospital of the University of Munich (LMU), 80802 Munich, Germany
- German Centre for Infection Research (DZIF), Partner Site Munich, 80802 Munich, Germany
| | - Michael Hoelscher
- Division of Infectious Diseases and Tropical Medicine, University Hospital of the University of Munich (LMU), 80802 Munich, Germany
- German Centre for Infection Research (DZIF), Partner Site Munich, 80802 Munich, Germany
| | - Elmar Saathoff
- Division of Infectious Diseases and Tropical Medicine, University Hospital of the University of Munich (LMU), 80802 Munich, Germany
- German Centre for Infection Research (DZIF), Partner Site Munich, 80802 Munich, Germany
| | - Mkunde Chachage
- National Institute of Medical Research (NIMR), Mbeya Medical Research Center (MMRC), Mbeya P.O. Box 2410, Tanzania
- Mbeya College of Health and Allied Sciences (UDSM-MCHAS), University of Dar es Salaam, Mbeya 608, Tanzania
| | - Kenneth Pfarr
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn (UKB), 53127 Bonn, Germany
- German Centre for Infection Research (DZIF), Partner Site Bonn-Cologne, 53127 Bonn, Germany
| | - Achim Hoerauf
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn (UKB), 53127 Bonn, Germany
- German Centre for Infection Research (DZIF), Partner Site Bonn-Cologne, 53127 Bonn, Germany
- German-West African Centre for Global Health and Pandemic Prevention (G-WAC), Partner Site Bonn, 53127 Bonn, Germany
| | - Inge Kroidl
- Division of Infectious Diseases and Tropical Medicine, University Hospital of the University of Munich (LMU), 80802 Munich, Germany
- German Centre for Infection Research (DZIF), Partner Site Munich, 80802 Munich, Germany
- Correspondence:
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Nieto-Sanchez C, Hatley DM, Grijalva MJ, Peeters Grietens K, Bates BR. Communication in Neglected Tropical Diseases' elimination: A scoping review and call for action. PLoS Negl Trop Dis 2022; 16:e0009774. [PMID: 36228006 PMCID: PMC9595560 DOI: 10.1371/journal.pntd.0009774] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 10/25/2022] [Accepted: 09/27/2022] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND Although the practice of communication is often called upon when intervening and involving communities affected by NTDs, the disciplinary framework of health communication research has been largely absent from NTD strategies. To illustrate how practices conceptualized and developed within the communication field have been applied in the context of NTD elimination, we conducted a scoping review focusing on two diseases currently targeted for elimination by the WHO: lymphatic filariasis and Chagas disease. METHODS We examined studies published between 2012 and 2020 in five electronic databases. Selected articles were required to (i) have explicit references to communication in either the abstract, title, or key words; (ii) further elaborate on the search terms (communication, message, media, participation and health education) in the body of the article; and (iii) sufficiently describe communication actions associated to those terms. Using the C-Change Socio-Ecological Model for Social and Behavior Change Communication as a reference, the articles were analysed to identify communication activities, theoretical frameworks, and/or rationales involved in their design, as well as their intended level of influence (individual, interpersonal, community, or enabling environment). RESULTS AND IMPLICATIONS A total of 43 articles were analysed. Most interventions conceptualized communication as a set of support tools or supplemental activities delivering information and amplifying pre-defined messages aimed at increasing knowledge, encouraging community involvement, promoting individual behavior change, or securing some degree of acceptability of proposed strategies. Although important attempts at further exploring communication capabilities were identified, particularly in participation-based strategies, for most studies, communication consisted of an underdeveloped and under-theorized approach. We contend that a more complex understanding of the capacities offered by the health communication field could help attain the biomedical and social justice goals proposed in NTD elimination strategies. Three ways in which the field of health communication could further enhance NTD efforts are presented: informing interventions with theory-based frameworks, exploring the political complexity of community participation in specific contexts, and identifying conceptualizations of culture implied in interventions' design. CONCLUSION This article is a call to action to consider the resources offered by the health communication field when researching, designing, or implementing NTD interventions.
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Affiliation(s)
- Claudia Nieto-Sanchez
- Socio-Ecological Health Research Unit, Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
- * E-mail:
| | - David M. Hatley
- Department of Epidemiology, University of London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Mario J. Grijalva
- Infectious and Tropical Disease Institute (ITDI), Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio, United States of America
- Center for Research in Health in Latin America (CISeAL), Facultad de Ciencias Exactas y Naturales, Pontifical Catholic University of Ecuador, Quito, Ecuador
| | - Koen Peeters Grietens
- Socio-Ecological Health Research Unit, Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
- Nagasaki, School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
| | - Benjamin R. Bates
- Infectious and Tropical Disease Institute (ITDI), Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio, United States of America
- Center for Research in Health in Latin America (CISeAL), Facultad de Ciencias Exactas y Naturales, Pontifical Catholic University of Ecuador, Quito, Ecuador
- School of Communication Studies, Ohio University, Athens, Ohio, United States of America
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Ricciardi A, Bennuru S, Tariq S, Kaur S, Wu W, Elkahloun AG, Arakelyan A, Shaik J, Dorward DW, Nutman TB, Tolouei Semnani R. Extracellular vesicles released from the filarial parasite Brugia malayi downregulate the host mTOR pathway. PLoS Negl Trop Dis 2021; 15:e0008884. [PMID: 33411714 PMCID: PMC7790274 DOI: 10.1371/journal.pntd.0008884] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 10/13/2020] [Indexed: 12/21/2022] Open
Abstract
We have previously shown that the microfilarial (mf) stage of Brugia malayi can inhibit the mammalian target of rapamycin (mTOR; a conserved serine/threonine kinase critical for immune regulation and cellular growth) in human dendritic cells (DC) and we have proposed that this mTOR inhibition is associated with the DC dysfunction seen in filarial infections. Extracellular vesicles (EVs) contain many proteins and nucleic acids including microRNAs (miRNAs) that might affect a variety of intracellular pathways. Thus, EVs secreted from mf may elucidate the mechanism by which the parasite is able to modulate the host immune response during infection. EVs, purified from mf of Brugia malayi and confirmed by size through nanoparticle tracking analysis, were assessed by miRNA microarrays (accession number GSE157226) and shown to be enriched (>2-fold, p-value<0.05, FDR = 0.05) for miR100, miR71, miR34, and miR7. The microarray analysis compared mf-derived EVs and mf supernatant. After confirming their presence in EVs using qPCR for these miRNA targets, web-based target predictions (using MIRPathv3, TarBAse and MicroT-CD) predicted that miR100 targeted mTOR and its downstream regulatory protein 4E-BP1. Our previous data with live parasites demonstrated that mf downregulate the phosphorylation of mTOR and its downstream effectors. Additionally, our proteomic analysis of the mf-derived EVs revealed the presence of proteins commonly found in these vesicles (data are available via ProteomeXchange with identifier PXD021844). We confirmed internalization of mf-derived EVs by human DCs and monocytes using confocal microscopy and flow cytometry, and further demonstrated through flow cytometry, that mf-derived EVs downregulate the phosphorylation of mTOR in human monocytes (THP-1 cells) to the same degree that rapamycin (a known mTOR inhibitor) does. Our data collectively suggest that mf release EVs that interact with host cells, such as DC, to modulate host responses. Lymphatic filariasis, a neglected tropical disease caused by parasitic worms which affects millions of individuals, represents an important public health concern due to its high morbidity that significantly diminishes quality of life. The parasite is able to establish a chronic infection by manipulating its host’s immune responses. The larval mf stage of the parasite is of particular interest as the parasites are present in the peripheral blood and in constant contact with the host’s immune cells. We decided to investigate the role of mf-derived EVs in the modulation of human antigen presenting cells during infection. We showed that mf release EVs that are similar to exosomes, and these parasite vesicles are readily internalized by human DC. The mf-derived EVs possess a unique miRNA profile and are enriched in miRNAs that can target the mTOR pathway. We have also demonstrated that purified mf-derived EVs are capable of inhibiting mTOR signaling in human monocytes. Collectively, our results suggest that mf release exosome-like vesicles that modulate the immune metabolism of host antigen presenting cells.
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Affiliation(s)
- Alessandra Ricciardi
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, Maryland, United States of America
- * E-mail:
| | - Sasisekhar Bennuru
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, Maryland, United States of America
| | - Sameha Tariq
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, Maryland, United States of America
| | - Sukhbir Kaur
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland, United States of America
| | - Weiwei Wu
- Microarray Core, Cancer Genetics and Comparative Genomics Branch, National Human Genome Research Institute, NIH, Bethesda, Maryland, United States of America
| | - Abdel G. Elkahloun
- Microarray Core, Cancer Genetics and Comparative Genomics Branch, National Human Genome Research Institute, NIH, Bethesda, Maryland, United States of America
| | - Anush Arakelyan
- Section of Intracellular Interactions, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, Maryland, United States of America
| | - Jahangheer Shaik
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, Maryland, United States of America
| | - David W. Dorward
- RML Microscopy Unit, RML Research Technologies Section, National Institute of Allergy and Infectious Diseases, NIH, Hamilton, Montana, United States of America
| | - Thomas B. Nutman
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, Maryland, United States of America
| | - Roshanak Tolouei Semnani
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, Maryland, United States of America
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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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Somerville AGT, Gleave K, Jones CM, Reimer LJ. The consequences of Brugia malayi infection on the flight and energy resources of Aedes aegypti mosquitoes. Sci Rep 2019; 9:18449. [PMID: 31804546 PMCID: PMC6895159 DOI: 10.1038/s41598-019-54819-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Accepted: 11/14/2019] [Indexed: 12/19/2022] Open
Abstract
Evidence from experimental infection studies has shown that infected mosquitoes exhibit altered host-seeking behaviours, with suppression and activation of behaviours dependent on the parasite's development stage. The mechanisms are poorly characterised; however, infections can impact mosquito energy reserves, thereby influencing key life-history traits and behaviours. In addition, filarial infection is likely detrimental to flight due to damage caused by developing worms. This study aimed to evaluate the impacts of Brugia malayi infection on Aedes aegypti flight parameters: distance, average speed, maximum speed and number of flight bursts, using a tethered flight mill. In addition, we explored whether differences in flight capacity may be due to the effect of infection on glycogen and lipid reserves. Infection with filarial worms significantly reduced flight distance but increased the number of flight bursts. Exposure to microfilaermic blood led to a significant decrease in average and maximum flight speeds even in the absence of an established infection. Mosquitoes fed on microfilaraemic blood showed reduced levels of glycogen (-37.9%) and lipids (-49.7%) compared to controls at nine days post-exposure. However, a one-hour period of flight activity caused an increase in lipid content for both infected and control mosquitoes. Consequential flight incapacitation may serve in explaining the heterogeneous distribution of lymphatic filariasis.
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Affiliation(s)
| | - Katherine Gleave
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Christopher M Jones
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Lisa J Reimer
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.
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Minetti C, Tettevi EJ, Mechan F, Prada JM, Idun B, Biritwum NK, Osei-Atweneboana MY, Reimer LJ. Elimination within reach: A cross-sectional study highlighting the factors that contribute to persistent lymphatic filariasis in eight communities in rural Ghana. PLoS Negl Trop Dis 2019; 13:e0006994. [PMID: 30608931 PMCID: PMC6342320 DOI: 10.1371/journal.pntd.0006994] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 01/22/2019] [Accepted: 11/13/2018] [Indexed: 12/20/2022] Open
Abstract
Background Despite the progress achieved in scaling-up mass drug administration (MDA) for lymphatic filariasis (LF) in Ghana, communities with persistent LF still exist even after 10 years of community treatment. To understand the reasons for persistence, we conducted a study to assess the status of disease elimination and understand the adherence to interventions including MDA and insecticide treated nets. Methodology and principal findings We conducted a parasitological and epidemiological cross-sectional study in adults from eight villages still under MDA in the Northern Region savannah and the coastal Western Region of the country. Prevalence of filarial antigen ranged 0 to 32.4% and in five villages the prevalence of night blood microfilaria (mf) was above 1%, ranging from 0 to 5.7%. Median mf density was 67 mf/ml (range: 10–3,560). LF antigen positivity was positively associated with male sex but negatively associated with participating in MDA the previous year. Male sex was also associated with a decreased probability of participating in MDA. A stochastic model (TRANSFIL) was used to assess the expected microfilaria prevalence under different MDA coverage scenarios using historical data on one community in the Western Region. In this example, the model simulations suggested that the slow decline in mf prevalence is what we would expect given high baseline prevalence and a high correlation between MDA adherence from year to year, despite high MDA coverage. Conclusions There is a need for an integrated quantitative and qualitative research approach to identify the variations in prevalence, associated risk factors and intervention coverage and use levels between and within regions and districts. Such knowledge will help target resources and enhance surveillance to the communities most at risk and to reach the 2020 LF elimination goals in Ghana. Lymphatic filariasis (LF) is a mosquito-borne disease and a leading cause of disability and chronic morbidity worldwide. Despite the progress achieved so far in stopping LF transmission by treating the affected communities with specific drugs over several years, areas where lymphatic filariasis persists still exist. Understanding the reasons behind this is pivotal to both reach and sustain elimination. We investigated the factors associated with filariasis persistence in various communities still under drug treatment from two regions of Ghana. We reported high variability in disease burden, adherence to drug treatment and mosquito net use between regions and communities. LF infection was associated with men and not taking the drugs, and men were also less likely to take treatment. Using mathematical modelling, we showed that slight increases in treatment coverage will accelerate elimination. Our findings highlight the reasons for LF persistence and provide guidance on how to successfully achieve elimination by refining drug treatment distribution and mosquito control interventions more tailored to individuals and communities. We also demonstrated the value of using field-collected data in mathematical models to assess the current status of disease elimination and to identify the gaps in control interventions.
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Affiliation(s)
- Corrado Minetti
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Edward J. Tettevi
- Department of Environmental Biology and Health, Council for Scientific and Industrial Research Water Research Institute, Accra, Ghana
| | - Frank Mechan
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Joaquín M. Prada
- Mathematics Institute, University of Warwick, Coventry, United Kingdom
- School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Bright Idun
- Department of Environmental Biology and Health, Council for Scientific and Industrial Research Water Research Institute, Accra, Ghana
| | | | - Mike Yaw Osei-Atweneboana
- Department of Environmental Biology and Health, Council for Scientific and Industrial Research Water Research Institute, Accra, Ghana
| | - Lisa J. Reimer
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- * E-mail:
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Pi-Bansa S, Osei JHN, Joannides J, Woode ME, Agyemang D, Elhassan E, Dadzie SK, Appawu MA, Wilson MD, Koudou BG, de Souza DK, Utzinger J, Boakye DA. Implementing a community vector collection strategy using xenomonitoring for the endgame of lymphatic filariasis elimination. Parasit Vectors 2018; 11:672. [PMID: 30587226 PMCID: PMC6307201 DOI: 10.1186/s13071-018-3260-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 12/05/2018] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND The global strategy for elimination of lymphatic filariasis is by annual mass drug administration (MDA). Effective implementation of this strategy in endemic areas reduces Wuchereria bancrofti in the blood of infected individuals to very low levels. This minimises the rate at which vectors successfully pick microfilariae from infected blood, hence requiring large mosquito numbers to detect infections. The aim of this study was to assess the feasibility of using trained community vector collectors (CVCs) to sample large mosquito numbers with minimal supervision at low cost for potential scale-up of this strategy. METHODS CVCs and supervisors were trained in mosquito sampling methods, i.e. human landing collections, pyrethrum spray collections and window exit traps. Mosquito sampling was done over a 13-month period. Validation was conducted by a research team as quality control for mosquitoes sampled by CVCs. Data were analyzed for number of mosquitoes collected and cost incurred by the research team and CVCs during the validation phase of the study. RESULTS A total of 31,064 and 8720 mosquitoes were sampled by CVCs and the research team, respectively. We found a significant difference (F(1,13) = 27.1606, P = 0.0001) in the total number of mosquitoes collected from southern and northern communities. Validation revealed similar numbers of mosquitoes sampled by CVCs and the research team, both in the wet (F(1,4) = 1.875, P = 0.309) and dry (F(1,4) = 2.276, P = 0.258) seasons in the southern communities, but was significantly different for both wet (F(1,4) = 0.022, P = 0.005) and dry (F(1,4 ) = 0.079, P = 0.033) seasons in the north. The cost of sampling mosquitoes per season was considerably lower by CVCs compared to the research team (15.170 vs 53.739 USD). CONCLUSIONS This study revealed the feasibility of using CVCs to sample large numbers of mosquitoes with minimal supervision from a research team at considerably lower cost than a research team for lymphatic filariasis xenomonitoring. However, evaluation of the selection and motivation of CVCs, acceptability of CVCs strategy and its epidemiological relevance for lymphatic filariasis xenomonitoring programmes need to be assessed in greater detail.
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Affiliation(s)
- Sellase Pi-Bansa
- Swiss Tropical and Public Health Institute, Basel, Switzerland. .,University of Basel, Basel, Switzerland. .,Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana.
| | - Joseph Harold Nyarko Osei
- Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana.,Department of Animal Biology and Conservation Science, University of Ghana, Legon, Ghana
| | - Joannitta Joannides
- Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | | | | | | | - Samuel Kweku Dadzie
- Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Maxwell Alexander Appawu
- Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Michael David Wilson
- Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Benjamin Guibehi Koudou
- Liverpool School of Tropical Medicine, Liverpool, UK.,Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Côte d'Ivoire
| | - Dziedzom Komi de Souza
- Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Daniel Adjei Boakye
- Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
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de Souza DK, Otchere J, Ahorlu CS, Adu-Amankwah S, Larbi IA, Dumashie E, McCarthy FA, King SA, Otoo S, Osabutey D, Osei JHN, Sedzro KM, Asiedu O, Dadzie SK, Ayi I, Marfo B, Biritwum NK, Boakye DA. Low Microfilaremia Levels in Three Districts in Coastal Ghana with at Least 16 Years of Mass Drug Administration and Persistent Transmission of Lymphatic Filariasis. Trop Med Infect Dis 2018; 3:tropicalmed3040105. [PMID: 30274501 PMCID: PMC6306872 DOI: 10.3390/tropicalmed3040105] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 09/20/2018] [Accepted: 09/22/2018] [Indexed: 11/16/2022] Open
Abstract
Ghana has been implementing mass drug administration (MDA) of ivermectin and albendazole for the elimination of lymphatic filariasis (LF) since the year 2000, as part of the Global Programme to Eliminate Lymphatic Filariasis (GPELF). It was estimated that 5⁻6 years of treatment would be sufficient to eliminate the disease. Tremendous progress has been made over the years, and treatment has stopped in many disease endemic districts. However, despite the successful implementation of MDA, there are districts with persistent transmission. In this study we assessed the epidemiology of LF in three adjoining districts that have received at least 16 years of MDA. The assessments were undertaken one year after the last MDA. 1234 adults and 182 children below the age of 10 years were assessed. The overall prevalence of circulating filarial antigen in the study participants was 8.3% (95% CI: 6.9⁻9.9), with an estimated microfilaria prevalence of 1.2%. The microfilarial intensity in positive individuals ranged from 1 to 57 microfilariae/mL of blood. Higher antigen prevalence was detected in males (13.0%; 95% CI: 10.3⁻16.2) compared to females (5.5%; 95% CI: 4.1⁻7.2). The presence of infection was also highest in individuals involved in outdoor commercial activities, with the risks of infection being four- to five-fold higher among farmers, fishermen, drivers and artisans, compared to all other occupations. Using bednets or participating in MDA did not significantly influence the risk of infection. No children below the age of 10 years were found with infection. Detection of Wb123 antibodies for current infections indicated a prevalence of 14.4% (95% CI: 8.1⁻23.0) in antigen-positive individuals above 10 years of age. No antibodies were detected in children 10 years or below. Assessment of infection within the An. gambiae vectors of LF indicated an infection rate of 0.9% (95% CI: 0.3⁻2.1) and infectivity rate of 0.5% (95% CI: 0.1⁻1.6). These results indicate low-level transmission within the districts, and suggest that it will require targeted interventions in order to eliminate the infection.
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Affiliation(s)
- Dziedzom K de Souza
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon-Accra, Ghana.
| | - Joseph Otchere
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon-Accra, Ghana.
| | - Collins S Ahorlu
- Department of Epidemiology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon-Accra, Ghana.
| | - Susan Adu-Amankwah
- Department of Epidemiology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon-Accra, Ghana.
| | - Irene A Larbi
- Department of Epidemiology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon-Accra, Ghana.
| | - Edward Dumashie
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon-Accra, Ghana.
| | - Frances A McCarthy
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon-Accra, Ghana.
| | - Sandra A King
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon-Accra, Ghana.
| | - Samson Otoo
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon-Accra, Ghana.
| | - Dickson Osabutey
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon-Accra, Ghana.
| | - Joseph H N Osei
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon-Accra, Ghana.
| | - Kojo M Sedzro
- Department of Epidemiology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon-Accra, Ghana.
| | - Odame Asiedu
- Neglected Tropical Diseases Programme, Ghana Health Service, Accra, Ghana.
| | - Samuel K Dadzie
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon-Accra, Ghana.
| | - Irene Ayi
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon-Accra, Ghana.
| | - Benjamin Marfo
- Neglected Tropical Diseases Programme, Ghana Health Service, Accra, Ghana.
| | | | - Daniel A Boakye
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon-Accra, Ghana.
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