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Sylla A, Chevillon C, Djidjiou-Demasse R, Seydi O, Campos CAV, Dogbe M, Fast KM, Pechal JL, Rakestraw A, Scott ME, Sandel MW, Jordan H, Benbow ME, Guégan JF. Understanding the transmission of bacterial agents of sapronotic diseases using an ecosystem-based approach: A first spatially realistic metacommunity model. PLoS Comput Biol 2024; 20:e1012435. [PMID: 39255272 DOI: 10.1371/journal.pcbi.1012435] [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: 10/06/2023] [Revised: 09/20/2024] [Accepted: 08/22/2024] [Indexed: 09/12/2024] Open
Abstract
Pathogens such as bacteria, fungi and viruses are important components of soil and aquatic communities, where they can benefit from decaying and living organic matter, and may opportunistically infect human and animal hosts. One-third of human infectious diseases is constituted by sapronotic disease agents that are natural inhabitants of soil or aquatic ecosystems. They are capable of existing and reproducing in the environment outside of the host for extended periods of time. However, as ecological research on sapronosis is infrequent and epidemiological models are even rarer, very little information is currently available. Their importance is overlooked in medical and veterinary research, as well as the relationships between free environmental forms and those that are pathogenic. Here, using dynamical models in realistic aquatic metacommunity systems, we analyze sapronosis transmission, using the human pathogen Mycobacterium ulcerans that is responsible for Buruli ulcer. We show that the persistence of bacilli in aquatic ecosystems is driven by a seasonal upstream supply, and that the attachment and development of cells to aquatic living forms is essential for such pathogen persistence and population dynamics. Our work constitutes the first set of metacommunity models of sapronotic disease transmission, and is highly flexible for adaptation to other types of sapronosis. The importance of sapronotic agents on animal and human disease burden needs better understanding and new models of sapronosis disease ecology to guide the management and prevention of this important group of pathogens.
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Affiliation(s)
- Ahmadou Sylla
- Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle (UMR MIVEGEC), Université de Montpellier (UM), Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD), Institut national de recherche pour l'agriculture, l'alimentation et l'environnement (INRAE), Montpellier, France
- Epidémiologie des maladies animales et zoonotiques (UMR EPIA), Université Clermont Auvergne, INRAE, VetAgro Sup, Saint-Genès-Champanelle, France
- Epidémiologie des maladies animales et zoonotiques (UMR EPIA), Université de Lyon, INRAE, VetAgro Sup, Marcy l'Etoile, France
- Department of Entomology, Michigan State University, East Lansing, Michigan, United States of America
| | - Christine Chevillon
- Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle (UMR MIVEGEC), Université de Montpellier (UM), Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD), Institut national de recherche pour l'agriculture, l'alimentation et l'environnement (INRAE), Montpellier, France
| | - Ramsès Djidjiou-Demasse
- Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle (UMR MIVEGEC), Université de Montpellier (UM), Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD), Institut national de recherche pour l'agriculture, l'alimentation et l'environnement (INRAE), Montpellier, France
| | - Ousmane Seydi
- Département Tronc Commun, École Polytechnique de Thiés, Thies, Senegal
| | - Carlos A Vargas Campos
- Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle (UMR MIVEGEC), Université de Montpellier (UM), Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD), Institut national de recherche pour l'agriculture, l'alimentation et l'environnement (INRAE), Montpellier, France
- Epidémiologie des maladies animales et zoonotiques (UMR EPIA), Université Clermont Auvergne, INRAE, VetAgro Sup, Saint-Genès-Champanelle, France
- Epidémiologie des maladies animales et zoonotiques (UMR EPIA), Université de Lyon, INRAE, VetAgro Sup, Marcy l'Etoile, France
| | - Magdalene Dogbe
- Department of Biological Sciences, Mississippi State University, MS, United States of America
| | - Kayla M Fast
- Department of Wildlife, Fisheries, and Aquaculture, Mississippi State University, Mississippi, United States of America
| | - Jennifer L Pechal
- Department of Entomology, Michigan State University, East Lansing, Michigan, United States of America
| | - Alex Rakestraw
- Department of Entomology, Michigan State University, East Lansing, Michigan, United States of America
| | - Matthew E Scott
- Department of Wildlife, Fisheries, and Aquaculture, Mississippi State University, Mississippi, United States of America
| | - Michael W Sandel
- Department of Wildlife, Fisheries, and Aquaculture, Mississippi State University, Mississippi, United States of America
- Fish and Wildlife Research Center, Mississippi State University, Mississippi, United States of America
| | - Heather Jordan
- Department of Biological Sciences, Mississippi State University, MS, United States of America
| | - Mark Eric Benbow
- Department of Entomology, Michigan State University, East Lansing, Michigan, United States of America
- Department of Osteopathic Medical Specialties, Michigan State University, East Lansing, Michigan,United States of America
- Ecology, Evolution and Behavior Program, Michigan State University, East Lansing, Michigan, United States of America
- AgBioResearch, Michigan State University, East Lansing, Michigan, United States of America
| | - Jean-François Guégan
- Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle (UMR MIVEGEC), Université de Montpellier (UM), Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD), Institut national de recherche pour l'agriculture, l'alimentation et l'environnement (INRAE), Montpellier, France
- Epidémiologie des maladies animales et zoonotiques (UMR EPIA), Université Clermont Auvergne, INRAE, VetAgro Sup, Saint-Genès-Champanelle, France
- Epidémiologie des maladies animales et zoonotiques (UMR EPIA), Université de Lyon, INRAE, VetAgro Sup, Marcy l'Etoile, France
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Sergio AR, Schimit PHT. Optimizing Contact Network Topological Parameters of Urban Populations Using the Genetic Algorithm. ENTROPY (BASEL, SWITZERLAND) 2024; 26:661. [PMID: 39202131 PMCID: PMC11353388 DOI: 10.3390/e26080661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/27/2024] [Revised: 07/11/2024] [Accepted: 07/26/2024] [Indexed: 09/03/2024]
Abstract
This paper explores the application of complex network models and genetic algorithms in epidemiological modeling. By considering the small-world and Barabási-Albert network models, we aim to replicate the dynamics of disease spread in urban environments. This study emphasizes the importance of accurately mapping individual contacts and social networks to forecast disease progression. Using a genetic algorithm, we estimate the input parameters for network construction, thereby simulating disease transmission within these networks. Our results demonstrate the networks' resemblance to real social interactions, highlighting their potential in predicting disease spread. This study underscores the significance of complex network models and genetic algorithms in understanding and managing public health crises.
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Perrin A, Khimoun A, Ollivier A, Richard Y, Pérez-Rodríguez A, Faivre B, Garnier S. Habitat fragmentation matters more than habitat loss: The case of host-parasite interactions. Mol Ecol 2023; 32:951-969. [PMID: 36461661 DOI: 10.1111/mec.16807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 11/29/2022] [Accepted: 12/01/2022] [Indexed: 12/05/2022]
Abstract
While ecologists agree that habitat loss has a substantial negative effect on biodiversity it is still very much a matter of debate whether habitat fragmentation has a lesser effect and whether this effect is positive or negative for biodiversity. Here, we assess the relative influence of tropical forest loss and fragmentation on the prevalence of vector-borne blood parasites of the genera Plasmodium and Haemoproteus in six forest bird species. We also determine whether habitat loss and fragmentation are associated with a rise or fall in prevalence. We sample more than 4000 individual birds from 58 forest sites in Guadeloupe and Martinique. Considering 34 host-parasite combinations independently and a fine characterization of the amount and spatial configuration of habitat, we use partial least square regressions to disentangle the relative effects of forest loss, forest fragmentation, landscape heterogeneity, and local weather conditions on spatial variability of parasite prevalence. Then we test for the magnitude and the sign of the effect of each environmental descriptor. Strikingly, we show that forest fragmentation explains twice as much of the variance in prevalence as habitat loss or landscape heterogeneity. In addition, habitat fragmentation leads to an overall rise in prevalence in Guadeloupe, but its effect is variable in Martinique. Both habitat loss and landscape heterogeneity exhibit taxon-specific effects. Our results suggest that habitat loss and fragmentation may have contrasting effects between tropical and temperate regions and that inter-specific interactions may not respond in the same way as more commonly used biodiversity metrics such as abundance and diversity.
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Affiliation(s)
- Antoine Perrin
- Biogéosciences, UMR 6282 CNRS, Université Bourgogne Franche-Comté, Dijon, France.,Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Aurélie Khimoun
- Biogéosciences, UMR 6282 CNRS, Université Bourgogne Franche-Comté, Dijon, France
| | - Anthony Ollivier
- Biogéosciences, UMR 6282 CNRS, Université Bourgogne Franche-Comté, Dijon, France
| | - Yves Richard
- Biogéosciences, UMR 6282 CNRS, Université Bourgogne Franche-Comté, Dijon, France
| | | | - Bruno Faivre
- Biogéosciences, UMR 6282 CNRS, Université Bourgogne Franche-Comté, Dijon, France
| | - Stéphane Garnier
- Biogéosciences, UMR 6282 CNRS, Université Bourgogne Franche-Comté, Dijon, France
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4
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Chavda VP, Haritopoulou-Sinanidou M, Bezbaruah R, Apostolopoulos V. Vaccination efforts for Buruli Ulcer. Expert Rev Vaccines 2022; 21:1419-1428. [PMID: 35962475 DOI: 10.1080/14760584.2022.2113514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Buruli ulcer is one of the most common mycobacterial diseases usually affecting poorer populations in tropical and subtropical environments. This disease, caused by M. ulcerans infection, has devastating effects for patients, with significant health and economic burden. Antibiotics are often used to treat affected individuals, but in most cases, surgery is necessary. AREA COVERED We present progress on Buruli ulcer vaccines and identify knowledge gaps in this neglected tropical disease. EXPERT OPINION The lack of appropriate infrastructure in endemic areas, as well as the severity of symptoms and lack of non-invasive treatment options, highlights the need for an effective vaccine to combat this disease. In terms of humoral immunity, it is vital to consider its significance and the magnitude to which it inhibits or slowdowns the progression of the disease. Only by answering these key questions will it be possible to tailor more appropriate vaccination and preventative provisions.
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Affiliation(s)
- Vivek P Chavda
- Department of Pharmaceutics and Pharmaceutical Technology, L M College of Pharmacy, Ahmedabad, India
| | | | - Rajashri Bezbaruah
- Department of Pharmaceutical Sciences, Faculty of Science and Engineering, Dibrugarh University, Dibrugarh, Assam, India
| | - Vasso Apostolopoulos
- Institute for Health and Sport, Immunology and Translational Research Group, Victoria University, Melbourne VIC, Australia.,Australian Institute for Musculoskeletal Science (AIMSS), Immunology Program, Melbourne VIC, Australia
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5
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Kurcheid J, Gordon CA, Clarke NE, Wangdi K, Kelly M, Lal A, Mutombo PN, Wang D, Mationg ML, Clements ACA, Muhi S, Bradbury RS, Biggs B, Page W, Williams G, McManus DP, Gray D. Neglected tropical diseases in Australia: a narrative review. Med J Aust 2022; 216:532-538. [DOI: 10.5694/mja2.51533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 10/25/2021] [Accepted: 11/02/2021] [Indexed: 11/17/2022]
Affiliation(s)
- Johanna Kurcheid
- Australian National University Canberra ACT
- Swiss Tropical and Public Health Institute Basel Switzerland
| | | | - Naomi E Clarke
- Australian National University Canberra ACT
- Kirby Institute University of New South Wales Sydney NSW
| | | | | | - Aparna Lal
- Australian National University Canberra ACT
| | - Polydor N Mutombo
- National Centre for Naturopathic Medicine Southern Cross University Lismore NSW
| | | | | | | | - Stephen Muhi
- Victorian Infectious Diseases Service Royal Melbourne Hospital Melbourne VIC
| | | | - Beverley‐Ann Biggs
- Victorian Infectious Diseases Service Royal Melbourne Hospital Melbourne VIC
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Receveur JP, Bauer A, Pechal JL, Picq S, Dogbe M, Jordan HR, Rakestraw AW, Fast K, Sandel M, Chevillon C, Guégan JF, Wallace JR, Benbow ME. A need for null models in understanding disease transmission: the example of Mycobacterium ulcerans (Buruli ulcer disease). FEMS Microbiol Rev 2022; 46:fuab045. [PMID: 34468735 PMCID: PMC8767449 DOI: 10.1093/femsre/fuab045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 08/12/2021] [Indexed: 01/19/2023] Open
Abstract
Understanding the interactions of ecosystems, humans and pathogens is important for disease risk estimation. This is particularly true for neglected and newly emerging diseases where modes and efficiencies of transmission leading to epidemics are not well understood. Using a model for other emerging diseases, the neglected tropical skin disease Buruli ulcer (BU), we systematically review the literature on transmission of the etiologic agent, Mycobacterium ulcerans (MU), within a One Health/EcoHealth framework and against Hill's nine criteria and Koch's postulates for making strong inference in disease systems. Using this strong inference approach, we advocate a null hypothesis for MU transmission and other understudied disease systems. The null should be tested against alternative vector or host roles in pathogen transmission to better inform disease management. We propose a re-evaluation of what is necessary to identify and confirm hosts, reservoirs and vectors associated with environmental pathogen replication, dispersal and transmission; critically review alternative environmental sources of MU that may be important for transmission, including invertebrate and vertebrate species, plants and biofilms on aquatic substrates; and conclude with placing BU within the context of other neglected and emerging infectious diseases with intricate ecological relationships that lead to disease in humans, wildlife and domestic animals.
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Affiliation(s)
- Joseph P Receveur
- Department of Entomology, Michigan State University, East Lansing, MI 48824, USA
| | - Alexandra Bauer
- Department of Entomology, Michigan State University, East Lansing, MI 48824, USA
| | - Jennifer L Pechal
- Department of Entomology, Michigan State University, East Lansing, MI 48824, USA
| | - Sophie Picq
- Department of Entomology, Michigan State University, East Lansing, MI 48824, USA
| | - Magdalene Dogbe
- Department of Biological Sciences, Mississippi State University, Starkville, MS, USA
| | - Heather R Jordan
- Department of Biological Sciences, Mississippi State University, Starkville, MS, USA
| | - Alex W Rakestraw
- Department of Biological and Environmental Sciences, The University of West Alabama, Livingston, AL, USA
| | - Kayla Fast
- Department of Biological and Environmental Sciences, The University of West Alabama, Livingston, AL, USA
| | - Michael Sandel
- Department of Biological and Environmental Sciences, The University of West Alabama, Livingston, AL, USA
| | - Christine Chevillon
- Maladies Infectieuses et Vecteurs : Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), Université de Montpellier (UM), Centre National de la Recherche Scientifique (CNRS), Institut pour la Recherche et le Développement, Montpellier, France
| | - Jean-François Guégan
- Maladies Infectieuses et Vecteurs : Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), Université de Montpellier (UM), Centre National de la Recherche Scientifique (CNRS), Institut pour la Recherche et le Développement, Montpellier, France
- UMR Animal, santé, territoires, risques et écosystèmes, Institut national de recherche pour l'agriculture, l'alimentation et l'environnement (INRAE), Centre de coopération internationale en recherche agronomique pour le développement (Cirad), Université de Montpellier (UM), Montpellier, France
| | - John R Wallace
- Department of Biology, Millersville University, Millersville, PA, USA
| | - M Eric Benbow
- Department of Entomology, Michigan State University, East Lansing, MI 48824, USA
- Ecology, Evolution and Behavior Program, Michigan State University, East Lansing, MI, USA
- AgBioResearch, Michigan State University, East Lansing, MI, USA
- Department of Osteopathic Medical Specialties, Michigan State University, East Lansing, MI, USA
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Linking the Mycobacterium ulcerans environment to Buruli ulcer disease: Progress and challenges. One Health 2021; 13:100311. [PMID: 34485670 PMCID: PMC8403752 DOI: 10.1016/j.onehlt.2021.100311] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 08/10/2021] [Accepted: 08/13/2021] [Indexed: 11/21/2022] Open
Abstract
Buruli ulcer (BU), the second most common mycobacterial disease in West Africa, is a necrotizing skin disease that can lead to high morbidity in affected patients. The disease is caused by Mycobacterium ulcerans (MU), whose major virulence factor is mycolactone. Although early infection can be treated with antibiotics, an effective preventative strategy is challenging due to unknown reservoir(s) and unresolved mode(s) of transmission. Further, disease occurrence in remote locations with limited access to health facilities further complicates disease burden and associated costs. We discuss here MU transmission hypotheses and investigations into environmental reservoirs and discuss successes and challenges of studying MU and Buruli ulcer across human, animal, and environmental interfaces. We argue that a One Health approach is needed to advance the understanding of MU transmission and designing management scenarios that prevent and respond to epidemics. Although previous work has provided significant insights into risk factors, epidemiology and clinical perspectives of disease, understanding the bacterial ecology, environmental niches and role of mycolactone in natural environments and during infection of the human host remains equally important to better understanding and preventing this mysterious disease.
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Muleta AJ, Lappan R, Stinear TP, Greening C. Understanding the transmission of Mycobacterium ulcerans: A step towards controlling Buruli ulcer. PLoS Negl Trop Dis 2021; 15:e0009678. [PMID: 34437549 PMCID: PMC8389476 DOI: 10.1371/journal.pntd.0009678] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Mycobacterium ulcerans is the causative agent of Buruli ulcer, a rare but chronic debilitating skin and soft tissue disease found predominantly in West Africa and Southeast Australia. While a moderate body of research has examined the distribution of M. ulcerans, the specific route(s) of transmission of this bacterium remain unknown, hindering control efforts. M. ulcerans is considered an environmental pathogen given it is associated with lentic ecosystems and human-to-human spread is negligible. However, the pathogen is also carried by various mammals and invertebrates, which may serve as key reservoirs and mechanical vectors, respectively. Here, we examine and review recent evidence from these endemic regions on potential transmission pathways, noting differences in findings between Africa and Australia, and summarising the risk and protective factors associated with Buruli ulcer transmission. We also discuss evidence suggesting that environmental disturbance and human population changes precede outbreaks. We note five key research priorities, including adoption of One Health frameworks, to resolve transmission pathways and inform control strategies to reduce the spread of Buruli ulcer. Buruli ulcer is a debilitating skin and soft tissue disease characterised by large ulcerative wounds that are treated with antibiotics or with adjunctive surgery for advanced cases. Found predominantly in West Africa and Southeast Australia, the causative agent is the environmental bacterial pathogen Mycobacterium ulcerans. Lack of understanding of transmission pathways, combined with the absence of a vaccine, has hindered efforts to control the spread of M. ulcerans. Here, in order to identify probable transmission pathways and inform future studies, we review literature linking M. ulcerans to environmental reservoirs, mammalian hosts, and potential invertebrate vectors. We also summarise factors and behaviours that reduce the risk of developing Buruli ulcer, to inform effective prevention strategies and further shed light on transmission pathways.
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Affiliation(s)
- Anthony J. Muleta
- Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Australia
| | - Rachael Lappan
- Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Australia
| | - Timothy P. Stinear
- Department of Microbiology and Immunology, Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Australia
| | - Chris Greening
- Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Australia
- Centre to Impact AMR, Monash University, Melbourne, Australia
- * E-mail:
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Simpson H, Tabah EN, Phillips RO, Frimpong M, Maman I, Ampadu E, Timothy J, Saunderson P, Pullan RL, Cano J. Mapping suitability for Buruli ulcer at fine spatial scales across Africa: A modelling study. PLoS Negl Trop Dis 2021; 15:e0009157. [PMID: 33657104 PMCID: PMC7959670 DOI: 10.1371/journal.pntd.0009157] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 03/15/2021] [Accepted: 01/17/2021] [Indexed: 12/14/2022] Open
Abstract
Buruli ulcer (BU) is a disabling and stigmatising neglected tropical disease (NTD). Its distribution and burden are unknown because of underdiagnosis and underreporting. It is caused by Mycobacterium ulcerans, an environmental pathogen whose environmental niche and transmission routes are not fully understood. The main control strategy is active surveillance to promote early treatment and thus limit morbidity, but these activities are mostly restricted to well-known endemic areas. A better understanding of environmental suitability for the bacterium and disease could inform targeted surveillance, and advance understanding of the ecology and burden of BU. We used previously compiled point-level datasets of BU and M. ulcerans occurrence, evidence for BU occurrence within national and sub-national areas, and a suite of relevant environmental covariates in a distribution modelling framework. We fitted relationships between BU and M. ulcerans occurrence and environmental predictors by applying regression and machine learning based algorithms, combined in an ensemble model to characterise the optimal ecological niche for the disease and bacterium across Africa at a resolution of 5km x 5km. Proximity to waterbodies was the strongest predictor of suitability for BU, followed potential evapotranspiration. The strongest predictors of suitability for M. ulcerans were deforestation and potential evapotranspiration. We identified patchy foci of suitability throughout West and Central Africa, including areas with no previous evidence of the disease. Predicted suitability for M. ulcerans was wider but overlapping with that of BU. The estimated population living in areas predicted suitable for the bacterium and disease was 46.1 million. These maps could be used to inform burden estimations and case searches which would generate a more complete understanding of the spatial distribution of BU in Africa, and may guide control programmes to identify cases beyond the well-known endemic areas.
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Affiliation(s)
- Hope Simpson
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Earnest Njih Tabah
- National Yaws, Leishmaniasis, Leprosy and Buruli ulcer Control Programme, Cameroon
| | - Richard O. Phillips
- School of Medical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Michael Frimpong
- School of Medical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Issaka Maman
- National Reference Laboratory for Buruli Ulcer Disease in Togo, Ecole Supérieure des Techniques Biologiques et Alimentaires (ESTBA), Laboratoire des Sciences Biologiques et des Substances Bioactives, Université de Lomé, Lomé, Togo
| | - Edwin Ampadu
- National Buruli Ulcer Control Program, Ghana Health Service, Accra, Ghana
| | - Joseph Timothy
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Paul Saunderson
- Accelerating Integrated Management (AIM) Initiative, Accra, Ghana
| | - Rachel L. Pullan
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Jorge Cano
- London School of Hygiene and Tropical Medicine, London, United Kingdom
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10
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Jagadesh S, Combe M, Couppié P, Le Turnier P, Epelboin L, Nacher M, Gozlan RE. Emerging human infectious diseases of aquatic origin: a comparative biogeographic approach using Bayesian spatial modelling. Int J Health Geogr 2019; 18:23. [PMID: 31694656 PMCID: PMC6833193 DOI: 10.1186/s12942-019-0188-6] [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: 04/04/2019] [Accepted: 10/25/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND With the increase in unprecedented and unpredictable disease outbreaks due to human-driven environmental changes in recent years, we need new analytical tools to map and predict the spatial distribution of emerging infectious diseases and identify the biogeographic drivers underpinning their emergence. The aim of the study was to identify and compare the local and global biogeographic predictors such as landscape and climate that determine the spatial structure of leptospirosis and Buruli Ulcer (BU). METHODS We obtained 232 hospital-confirmed leptospirosis (2007-2017) cases and 236 BU cases (1969-2017) in French Guiana. We performed non-spatial and spatial Bayesian regression modeling with landscape and climate predictor variables to characterize the spatial structure and the environmental drivers influencing the distribution of the two diseases. RESULTS Our results show that the distribution of both diseases is spatially dependent on environmental predictors such as elevation, topological wetness index, proximity to cropland and increasing minimum temperature at the month of potential infection. However, the spatial structure of the two diseases caused by bacterial pathogens occupying similar aquatic niche was different. Leptospirosis was widely distributed across the territory while BU was restricted to the coastal riverbeds. CONCLUSIONS Our study shows that a biogeographic approach is an effective tool to identify, compare and predict the geographic distribution of emerging diseases at an ecological scale which are spatially dependent to environmental factors such as topography, land cover and climate.
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Affiliation(s)
- Soushieta Jagadesh
- ISEM, UMR226, CNRS, Université de Montpellier, IRD, EPHE, 34090, Montpellier, France.
- Equipe EPAT 3593 Ecosystèmes amazoniens et pathologie tropicale, Université de Guyane, Cayenne, French Guiana.
| | - Marine Combe
- ISEM, UMR226, CNRS, Université de Montpellier, IRD, EPHE, 34090, Montpellier, France
| | - Pierre Couppié
- Equipe EPAT 3593 Ecosystèmes amazoniens et pathologie tropicale, Université de Guyane, Cayenne, French Guiana
- Service de Dermatologie, Centre hospitalier Andrée Rosemon, av des Flamboyants, 97304, Cayenne Cedex, French Guiana
| | - Paul Le Turnier
- Unité des maladies infectieuses et tropicales, Centre hospitalier Andrée Rosemon, av des Flamboyants, 97304, Cayenne Cedex, French Guiana
| | - Loïc Epelboin
- Unité des maladies infectieuses et tropicales, Centre hospitalier Andrée Rosemon, av des Flamboyants, 97304, Cayenne Cedex, French Guiana
| | - Mathieu Nacher
- Equipe EPAT 3593 Ecosystèmes amazoniens et pathologie tropicale, Université de Guyane, Cayenne, French Guiana
- Centre d'investigation clinique (CIC Inserm 1424), Centre hospitalier Andrée Rosemon, Avenue des Flamboyants, 97304, Cayenne Cedex, French Guiana
| | - Rodolphe Elie Gozlan
- ISEM, UMR226, CNRS, Université de Montpellier, IRD, EPHE, 34090, Montpellier, France
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Combe M, Gozlan RE, Jagadesh S, Velvin CJ, Ruffine R, Demar MP, Couppié P, Djossou F, Nacher M, Epelboin L. Comparison of Mycobacterium ulcerans (Buruli ulcer) and Leptospira sp. (Leptospirosis) dynamics in urban and rural settings. PLoS Negl Trop Dis 2019; 13:e0007074. [PMID: 30615683 PMCID: PMC6336349 DOI: 10.1371/journal.pntd.0007074] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 01/17/2019] [Accepted: 12/13/2018] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND Zoonotic pathogens respond to changes in host range and/or pathogen, vector and host ecology. Environmental changes (biodiversity, habitat changes, variability in climate), even at a local level, lead to variability in environmental pathogen dynamics and can facilitate their transmission from natural reservoirs to new susceptible hosts. Whilst the environmental dynamics of aquatic bacteria are directly linked to seasonal changes of their habitat they also rely on the ecological processes underpining their transmission. However data allowing the comparison of these ecological processes are lacking. Here we compared the environmental dynamics of generalist and vector-borne aquatic bacterial pathogens in the same unit of time and space, and across rural and urban habitats in French Guiana (South America). PRINCIPAL FINDINGS Using Leptospira sp. and Mycobacterium ulcerans we performed an environmental survey that allowed the detection of both pathogens in urban vs. rural areas, and during rainy vs. dry weather conditions. All samples were subjected to qPCR amplifications of LipL32 (Leptospira sp.) and IS2404 and KR (M. ulcerans) genetic markers. We found (i) a greater presence of M. ulcerans in rural areas compared with Leptospira sp., (ii) that modified urban environments were more favourable to the establishment of both pathogens, (iii) that Leptospira sp. presence was enhanced during the rainy season and M. ulcerans during the dry period, and (iv) differences in the spatial distribution of both bacteria across urban sites, probably due to the mode of dissemination of each pathogen in the environment. CONCLUSIONS We propose that in French Guiana simplified and modified urban ecosystems might favour leptospirosis and Buruli ulcer emergence and transmission. Moreover, disease risk was also constrained by seasonality. We suggest that the prevention of aquatic bacterial disease emergence in impoverished urban areas of developing countries would benefit from seasonal diseases targeted surveys, which would maximise limited budgets from cash-strapped health agencies.
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Affiliation(s)
- Marine Combe
- ISEM UMR226, Université de Montpellier, CNRS, IRD, EPHE, Montpellier, France
| | | | - Soushieta Jagadesh
- ISEM UMR226, Université de Montpellier, CNRS, IRD, EPHE, Montpellier, France
| | | | - Rolland Ruffine
- MIVEGEC, IRD, CNRS, Université de Montpellier, Montpellier, Centre IRD de Cayenne, Guyane française
| | - Magalie Pierre Demar
- Equipe EA 3593, Ecosystèmes amazoniens et pathologie tropicale, Université de la Guyane, Cayenne, Guyane française
- Laboratoire hospitalo-universitaire de parasitologie mycologie, Centre hospitalier Andrée Rosemon, Guyane française
| | - Pierre Couppié
- Equipe EA 3593, Ecosystèmes amazoniens et pathologie tropicale, Université de la Guyane, Cayenne, Guyane française
- Service de Dermatologie, Cayenne Hospital, rue des Flamboyant, Cayenne, French Guiana, France
| | - Felix Djossou
- Equipe EA 3593, Ecosystèmes amazoniens et pathologie tropicale, Université de la Guyane, Cayenne, Guyane française
- Unité des maladies infectieuses et tropicales, Centre hospitalier Andrée Rosemon, av des Flamboyants, Guyane française
| | - Mathieu Nacher
- Centre d’investigation clinique (CIC Inserm 1424), Centre hospitalier Andrée Rosemon, Guyane française
| | - Loïc Epelboin
- Equipe EA 3593, Ecosystèmes amazoniens et pathologie tropicale, Université de la Guyane, Cayenne, Guyane française
- Unité des maladies infectieuses et tropicales, Centre hospitalier Andrée Rosemon, av des Flamboyants, Guyane française
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Abstract
Mycobacterium ulcerans is recognised as the third most common mycobacterial infection worldwide. It causes necrotising infections of skin and soft tissue and is classified as a neglected tropical disease by the World Health Organization (WHO). However, despite extensive research, the environmental reservoir of the organism and mode of transmission of the infection to humans remain unknown. This limits the ability to design and implement public health interventions to effectively and consistently prevent the spread and reduce the incidence of this disease. In recent years, the epidemiology of the disease has changed. In most endemic regions of the world, the number of cases reported to the WHO are reducing, with a 64% reduction in cases reported worldwide in the last 9 years. Conversely, in a smaller number of countries including Australia and Nigeria, reported cases are increasing at a rapid rate, new endemic areas continue to appear, and in Australia cases are becoming more severe. The reasons for this changing epidemiology are unknown. We review the epidemiology of M. ulcerans disease worldwide, and document recent changes. We also outline and discuss the current state of knowledge on the ecology of M. ulcerans, possible transmission mechanisms to humans and what may be enabling the spread of M. ulcerans into new endemic areas.
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Yerramilli A, Tay EL, Stewardson AJ, Fyfe J, O’Brien DP, Johnson PDR. The association of rainfall and Buruli ulcer in southeastern Australia. PLoS Negl Trop Dis 2018; 12:e0006757. [PMID: 30222751 PMCID: PMC6160213 DOI: 10.1371/journal.pntd.0006757] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 09/27/2018] [Accepted: 08/16/2018] [Indexed: 11/21/2022] Open
Abstract
Background Buruli ulcer has been increasing in incidence in southeastern Australia with unclear transmission mechanisms. We aimed to investigate the link between rainfall and case numbers in two endemic areas of the state of Victoria; the Bellarine and Mornington Peninsulas. Methodology We created yearly and monthly graphs comparing rainfall with local Buruli ulcer incidence for the period 2004–2016 by endemic region and then considered a range of time lag intervals of 0–24 months to investigate patterns of correlation. Conclusions Optimal positive correlation for the Bellarine Peninsula occurred with a 12-month prior rainfall lag, however, no significant correlation was observed on the Mornington Peninsula for any time lag. These results provide an update in evidence to further explore transmission mechanisms which may differ between these geographically proximate endemic regions. Buruli ulcer, a mycobacterial infection resulting in destructive soft tissue lesions, has been increasing in incidence in southeastern Australia over recent years. Exact transmission mechanisms and therefore preventative measures remain unclear. We aimed to investigate a possible link between Buruli ulcer and rainfall for two major endemic areas of the state of Victoria; the Bellarine and Mornington Peninsulas. Our results demonstrate a positive correlation with rainfall on the Bellarine Peninsula with a prior rainfall lag of 12 months but no correlation on the Mornington Peninsula. Established time-frames such as the incubation period and average delay to diagnosis (due to slow and often asymptomatic progression of the disease) make up a total of at least 5–6 months. On the Bellarine Peninsula, there appears to be another 5–6 months of unaccounted time from rainfall to transmission of the pathogen. This provides a basis to explore previously proposed transmission mechanisms which, based on the discrepancy noted with rainfall correlation, may differ between endemic regions.
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Affiliation(s)
- Arvind Yerramilli
- University of Melbourne, Department of Medicine, Austin Health, Heidelberg, Victoria, Australia
- Department of Medicine and Infectious Diseases, The Royal Melbourne Hospital, University of Melbourne, Parkville, Victoria, Australia
- * E-mail: (AY); (PDRJ)
| | - Ee Laine Tay
- Health Protection Branch, Department of Health & Human Services, Melbourne, Victoria, Australia
| | - Andrew J. Stewardson
- Infectious Diseases Department, Austin Health, Heidelberg, Victoria, Australia
- Department of Infectious Diseases, Alfred Hospital and Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Janet Fyfe
- Victorian Infectious Diseases References Laboratory, Peter Doherty Institute for Infection and Immunity, Parkville, Victoria, Australia
| | - Daniel P. O’Brien
- Department of Medicine and Infectious Diseases, The Royal Melbourne Hospital, University of Melbourne, Parkville, Victoria, Australia
- Department of Infectious Diseases, Barwon Health, Geelong, Victoria, Australia
| | - Paul D. R. Johnson
- University of Melbourne, Department of Medicine, Austin Health, Heidelberg, Victoria, Australia
- Infectious Diseases Department, Austin Health, Heidelberg, Victoria, Australia
- * E-mail: (AY); (PDRJ)
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15
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Sanhueza D, Chevillon C, Bouzinbi N, Godreuil S, Guégan JF. Chitin Increases Mycobacterium ulcerans Growth in Acidic Environments. Microbes Environ 2018; 33:234-237. [PMID: 29910219 PMCID: PMC6031397 DOI: 10.1264/jsme2.me17160] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Accepted: 04/11/2018] [Indexed: 11/12/2022] Open
Abstract
Species with a chitinous exoskeleton are overrepresented among the aquatic organisms carrying Mycobacterium ulcerans (MU) in nature and laboratory experiments have demonstrated the enhancing effects of chitin on the growth of MU. Field surveys identified pH as one of the key parameters delineating the distribution of MU in tropical regions. The present study investigated the relationship between chitin and pH in MU growth. By focusing on pH variations in the field, our results revealed that chitin enhanced MU growth in acidic environments. The present study provides new information on the ecological conditions favoring the development of this mycobacterium in nature.
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Affiliation(s)
- Daniel Sanhueza
- MIVEGEC, IRD, CNRS, Université de MontpellierMontpellierFrance
| | | | - Nicolas Bouzinbi
- MIVEGEC, IRD, CNRS, Université de MontpellierMontpellierFrance
- Laboratoire de bactériologie, CHU de Montpellier, Université de MontpellierFrance
| | - Sylvain Godreuil
- MIVEGEC, IRD, CNRS, Université de MontpellierMontpellierFrance
- Laboratoire de bactériologie, CHU de Montpellier, Université de MontpellierFrance
| | - Jean-François Guégan
- MIVEGEC, IRD, CNRS, Université de MontpellierMontpellierFrance
- International United Nations Program FutureEarth, OneHealth Core Research ProgramMontrealCanada
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Schimit P, Pereira F. Disease spreading in complex networks: A numerical study with Principal Component Analysis. EXPERT SYSTEMS WITH APPLICATIONS 2018; 97:41-50. [PMID: 32288338 PMCID: PMC7126495 DOI: 10.1016/j.eswa.2017.12.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 11/21/2017] [Accepted: 12/09/2017] [Indexed: 05/03/2023]
Abstract
Disease spreading models need a population model to organize how individuals are distributed over space and how they are connected. Usually, disease agent (bacteria, virus) passes between individuals through these connections and an epidemic outbreak may occur. Here, complex networks models, like Erdös-Rényi, Small-World, Scale-Free and Barábasi-Albert will be used for modeling a population, since they are used for social networks; and the disease will be modeled by a SIR (Susceptible-Infected-Recovered) model. The objective of this work is, regardless of the network/population model, analyze which topological parameters are more relevant for a disease success or failure. Therefore, the SIR model is simulated in a wide range of each network model and a first analysis is done. By using data from all simulations, an investigation with Principal Component Analysis (PCA) is done in order to find the most relevant topological and disease parameters.
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Affiliation(s)
- P.H.T. Schimit
- Informatics and Knowledge Management Graduate Program, Universidade Nove de Julho, Rua Vergueiro, 235/249, CEP 01504-000 São Paulo, SP, Brazil
| | - F.H. Pereira
- Informatics and Knowledge Management Graduate Program, Universidade Nove de Julho, Rua Vergueiro, 235/249, CEP 01504-000 São Paulo, SP, Brazil
- Industrial Engineering Graduate Program, Universidade Nove de Julho, Rua Vergueiro, 235/249, CEP 01504-000 São Paulo, SP, Brazil
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Comparative Genomics Shows That Mycobacterium ulcerans Migration and Expansion Preceded the Rise of Buruli Ulcer in Southeastern Australia. Appl Environ Microbiol 2018; 84:AEM.02612-17. [PMID: 29439984 DOI: 10.1128/aem.02612-17] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 01/25/2018] [Indexed: 02/07/2023] Open
Abstract
Since 2000, cases of the neglected tropical disease Buruli ulcer, caused by infection with Mycobacterium ulcerans, have increased 100-fold around Melbourne (population 4.4 million), the capital of Victoria, in temperate southeastern Australia. The reasons for this increase are unclear. Here, we used whole-genome sequence comparisons of 178 M. ulcerans isolates obtained primarily from human clinical specimens, spanning 70 years, to model the population dynamics of this pathogen from this region. Using phylogeographic and advanced Bayesian phylogenetic approaches, we found that there has been a migration of the pathogen from the east end of the state, beginning in the 1980s, 300 km west to the major human population center around Melbourne. This move was then followed by a significant increase in M. ulcerans population size. These analyses inform our thinking around Buruli ulcer transmission and control, indicating that M. ulcerans is introduced to a new environment and then expands, rather than it being from the awakening of a quiescent pathogen reservoir.IMPORTANCE Buruli ulcer is a destructive skin and soft tissue infection caused by Mycobacterium ulcerans and is characterized by progressive skin ulceration, which can lead to permanent disfigurement and long-term disability. Despite the majority of disease burden occurring in regions of West and central Africa, Buruli ulcer is also becoming increasingly common in southeastern Australia. Major impediments to controlling disease spread are incomplete understandings of the environmental reservoirs and modes of transmission of M. ulcerans The significance of our research is that we used genomics to assess the population structure of this pathogen at the Australian continental scale. We have then reconstructed a historical bacterial spread and modeled demographic dynamics to reveal bacterial population expansion across southeastern Australia. These findings provide explanations for the observed epidemiological trends with Buruli ulcer and suggest possible management to control disease spread.
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Buruli Ulcer, a Prototype for Ecosystem-Related Infection, Caused by Mycobacterium ulcerans. Clin Microbiol Rev 2017; 31:31/1/e00045-17. [PMID: 29237707 DOI: 10.1128/cmr.00045-17] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Buruli ulcer is a noncontagious disabling cutaneous and subcutaneous mycobacteriosis reported by 33 countries in Africa, Asia, Oceania, and South America. The causative agent, Mycobacterium ulcerans, derives from Mycobacterium marinum by genomic reduction and acquisition of a plasmid-borne, nonribosomal cytotoxin mycolactone, the major virulence factor. M. ulcerans-specific sequences have been readily detected in aquatic environments in food chains involving small mammals. Skin contamination combined with any type of puncture, including insect bites, is the most plausible route of transmission, and skin temperature of <30°C significantly correlates with the topography of lesions. After 30 years of emergence and increasing prevalence between 1970 and 2010, mainly in Africa, factors related to ongoing decreasing prevalence in the same countries remain unexplained. Rapid diagnosis, including laboratory confirmation at the point of care, is mandatory in order to reduce delays in effective treatment. Parenteral and potentially toxic streptomycin-rifampin is to be replaced by oral clarithromycin or fluoroquinolone combined with rifampin. In the absence of proven effective primary prevention, avoiding skin contamination by means of clothing can be implemented in areas of endemicity. Buruli ulcer is a prototype of ecosystem pathology, illustrating the impact of human activities on the environment as a source for emerging tropical infectious diseases.
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19
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Ruf MT, Steffen C, Bolz M, Schmid P, Pluschke G. Infiltrating leukocytes surround early Buruli ulcer lesions, but are unable to reach the mycolactone producing mycobacteria. Virulence 2017; 8:1918-1926. [PMID: 28873327 PMCID: PMC5810495 DOI: 10.1080/21505594.2017.1370530] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Affiliation(s)
- Marie-Thérèse Ruf
- a Swiss Tropical and Public Health Institute , Basel , Switzerland.,b University of Basel , Basel , Switzerland
| | - Christina Steffen
- c Department of Surgery , Cairns Hospital , Cairns , QLD , Australia
| | - Miriam Bolz
- a Swiss Tropical and Public Health Institute , Basel , Switzerland.,b University of Basel , Basel , Switzerland
| | - Peter Schmid
- a Swiss Tropical and Public Health Institute , Basel , Switzerland.,b University of Basel , Basel , Switzerland
| | - Gerd Pluschke
- a Swiss Tropical and Public Health Institute , Basel , Switzerland.,b University of Basel , Basel , Switzerland
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20
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Aboagye SY, Ampah KA, Ross A, Asare P, Otchere ID, Fyfe J, Yeboah-Manu D. Seasonal Pattern of Mycobacterium ulcerans, the Causative Agent of Buruli Ulcer, in the Environment in Ghana. MICROBIAL ECOLOGY 2017; 74:350-361. [PMID: 28238016 PMCID: PMC5496970 DOI: 10.1007/s00248-017-0946-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 01/31/2017] [Indexed: 06/06/2023]
Abstract
This study aimed to contribute to the understanding of Mycobacterium ulcerans (MU) ecology by analysing both clinical and environmental samples collected from ten communities along two major river basins (Offin and Densu) associated with Buruli ulcer (BU) at different seasons. We collected clinical samples from presumptive BU cases and environmental samples from ten communities. Following DNA extraction, clinical samples were confirmed by IS2404 PCR and environmental samples were confirmed by targeting MU-specific genes, IS2404, IS2606 and the ketoreductase (KR) using real-time PCR. Environmental samples were first analysed for IS2404; after which, IS2404-positive samples were multiplexed for the IS2606 and KR gene. Our findings indicate an overall decline in BU incidence along both river basins, although incidence at Densu outweighs that of Offin. Overall, 1600 environmental samples were screened along Densu (434, 27 %) and Offin (1166, 73 %) and MU was detected in 139 (9 %) of the combined samples. The positivity of MU along the Densu River basin was 89/434 (20.5 %), whilst that of the Offin River basin was 50/1166 (4.3 %). The DNA was detected mainly in snails (5/6, 83 %), moss (8/40, 20 %), soil (55/586, 9 %) and vegetation (55/675, 8 %). The proportion of MU positive samples recorded was higher during the months with higher rainfall levels (126/1175, 11 %) than during the dry season months (13/425, 3 %). This study indicates for the first time that there is a seasonal pattern in the presence of MU in the environment, which may be related to recent rainfall or water in the soil.
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Affiliation(s)
- Samuel Yaw Aboagye
- Bacteriology Department, Noguchi Memorial Institute for Medical Research, University of Ghana, P.O. Box LG 581, Legon, Accra, Ghana
- Institute of Environmental and Sanitation Studies, University of Ghana, Accra, Ghana
| | - Kobina Assan Ampah
- Bacteriology Department, Noguchi Memorial Institute for Medical Research, University of Ghana, P.O. Box LG 581, Legon, Accra, Ghana
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Amanda Ross
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Prince Asare
- Bacteriology Department, Noguchi Memorial Institute for Medical Research, University of Ghana, P.O. Box LG 581, Legon, Accra, Ghana
| | - Isaac Darko Otchere
- Bacteriology Department, Noguchi Memorial Institute for Medical Research, University of Ghana, P.O. Box LG 581, Legon, Accra, Ghana
| | - Janet Fyfe
- Victorian Infectious Diseases Reference Laboratory, Melbourne, VIC, Australia
| | - Dorothy Yeboah-Manu
- Bacteriology Department, Noguchi Memorial Institute for Medical Research, University of Ghana, P.O. Box LG 581, Legon, Accra, Ghana.
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Meyin A Ebong S, García-Peña GE, Pluot-Sigwalt D, Marsollier L, Le Gall P, Eyangoh S, Guégan JF. Ecology and Feeding Habits Drive Infection of Water Bugs with Mycobacterium ulcerans. ECOHEALTH 2017; 14:329-341. [PMID: 28315039 DOI: 10.1007/s10393-017-1228-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Revised: 02/16/2017] [Accepted: 02/19/2017] [Indexed: 06/06/2023]
Abstract
Mycobacterium ulcerans (MU), the causative agent of Buruli ulcer, is present in a wide spectrum of environments, including terrestrial and aquatic ecosystems in tropical regions. The most promising studies on the epidemiological risk of this disease suggest that some ecological settings may favor infection of animals with MU including human. A species' needs and impacts on resources and the environment, i.e., its ecological niche, may influence its susceptibility to be infected by this microbial form. For example, some Naucoridae may dive in fresh waters to prey upon infected animals and thus may get infected with MU. However, these studies have rarely considered that inference on the ecological settings favoring infection and transmission may be confounded because host carrier sister species have similar ecological niches, and potentially the same host-microbe interactions. Hence, a relationship between the ecological niche of Naucoridae and its infection with MU may be due to a symbiotic relationship between the host and the pathogen, rather than its ecological niche. To account for this confounding effect, we investigated the relationships between surrogates of the ecological niche of water bug species and their susceptibility to MU, by performing phylogenetic comparative analyses on a large dataset of 11 families of water bugs collected in 10 different sites across Cameroon, central Africa. Our results indicate that MU circulates and infects a couple of host taxa, i.e., Belostomatidae, Naucoridae, living both in the aquatic vegetation and as predators inside the trophic network and sister species of water bugs have indeed similar host-microbe interactions with MU.
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Affiliation(s)
- Solange Meyin A Ebong
- UMR MIVEGEC IRD, CNRS, Université de Montpellier, Centre IRD de Montpellier, BP 64501, 34394, Montpellier Cedex, France.
- Service de Mycobactériologie, Centre Pasteur du Cameroun, BP 1274, Yaoundé, Cameroon.
- Laboratoire de Parasitologie et Ecologie, Faculté des Sciences, Université de Yaoundé I, Yaoundé, Cameroon.
| | - Gabriel E García-Peña
- UMR MIVEGEC IRD, CNRS, Université de Montpellier, Centre IRD de Montpellier, BP 64501, 34394, Montpellier Cedex, France
- Centre de Synthèse et d'Analyse sur la Biodiversité (CESAB), 13857, Aix-en-Provence Cedex 3, France
| | - Dominique Pluot-Sigwalt
- Département Systématique et Evolution, UMR7205 CNRS/MNHN, Museum National d'Histoire Naturelle, Paris, France
| | - Laurent Marsollier
- Inserm Avenir ATOMycA CRCNA Inserm U892 & CNRS U6299, Université et CHU d'Angers, Angers, France
| | - Philippe Le Gall
- UMR EGCE IRD, CNRS et Université Paris-Sud Orsay, Centre CNRS de Gif-sur-Yvette, 91198, Gif-sur-Yvette Cedex, France
| | - Sara Eyangoh
- Service de Mycobactériologie, Centre Pasteur du Cameroun, BP 1274, Yaoundé, Cameroon
| | - Jean-François Guégan
- UMR MIVEGEC IRD, CNRS, Université de Montpellier, Centre IRD de Montpellier, BP 64501, 34394, Montpellier Cedex, France
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22
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Douine M, Gozlan R, Nacher M, Dufour J, Reynaud Y, Elguero E, Combe M, Velvin CJ, Chevillon C, Berlioz-Arthaud A, Labbé S, Sainte-Marie D, Guégan JF, Pradinaud R, Couppié P. Mycobacterium ulcerans infection (Buruli ulcer) in French Guiana, South America, 1969-2013: an epidemiological study. Lancet Planet Health 2017; 1:e65-e73. [PMID: 29851583 DOI: 10.1016/s2542-5196(17)30009-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 03/08/2017] [Accepted: 03/09/2017] [Indexed: 06/08/2023]
Abstract
BACKGROUND Mycobacterium ulcerans infection is the third most common mycobacterial disease in the world after tuberculosis and leprosy. To date, transmission pathways from its environmental reservoir to humans are still unknown. In South America, French Guiana has the highest reported number of M ulcerans infections across the continent. This empirical study aimed to characterise the epidemiology of M ulcerans infection in French Guiana between 1969 and 2013. METHODS Data were collected prospectively mainly by two dermatologists at Cayenne Hospital's dermatology department between Jan 1, 1969, and Dec 31, 2013, for age, date of diagnosis, sex, residence, location of the lesion, type of lesion, associated symptoms, and diagnostic method (smear, culture, PCR, or histology) for all confirmed and suspected cases of M ulcerans. We obtained population data from censuses. We calculated mean M ulcerans infection incidences, presented as the number of cases per 100 000 person-years. FINDINGS 245 patients with M ulcerans infections were reported at Cayenne Hospital's dermatology department during the study period. M ulcerans infection incidence decreased over time, from 6·07 infections per 100 000 person-years (95% CI 4·46-7·67) in 1969-83 to 4·77 infections per 100 000 person-years (3·75-5·79) in 1984-98 and to 3·49 infections per 100 000 person-years (2·83-4·16) in 1999-2013. The proportion of children with infections also declined with time, from 42 (76%) of 55 patients in 1969-83 to 26 (31%) of 84 in 1984-98 and to 22 (21%) of 106 in 1999-2013. Most cases occurred in coastal areas surrounded by marshy savannah (incidence of 21·08 per 100 000 person-years in Sinnamary and 21·18 per 100 000 person-years in Mana). Lesions mainly affected limbs (lower limbs 161 [66%] patients; upper limbs 60 [24%] patients). We diagnosed no bone infections. INTERPRETATION The decrease of M ulcerans infection incidence and the proportion of children with infections over a 45 year period in this ultra-peripheral French territory might have been mostly driven by improving living conditions, prophylactic recommendations, and access to health care. FUNDING Agence Nationale de la Recherche.
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Affiliation(s)
- Maylis Douine
- Centre d'Investigation Clinique, Institut National de la Santé et de la Recherche Médicale 1424, Cayenne Hospital, Cayenne, French Guiana; Université de Guyane, EA3593 Epidémiologie des Parasitoses Tropicales, Cayenne, French Guiana
| | - Rodolphe Gozlan
- Institut de Recherche pour le Développement Unité Mixte de Recherche Biologie des Organismes et Ecosystèmes Aquatiques, Université Pierre et Marie Curie, Muséum National d'Histoire Naturelle, Paris, France
| | - Mathieu Nacher
- Centre d'Investigation Clinique, Institut National de la Santé et de la Recherche Médicale 1424, Cayenne Hospital, Cayenne, French Guiana; Université de Guyane, EA3593 Epidémiologie des Parasitoses Tropicales, Cayenne, French Guiana
| | - Julie Dufour
- Service de Dermatologie, Cayenne Hospital, Cayenne, French Guiana
| | - Yann Reynaud
- Institut Pasteur de la Guadeloupe, Tuberculosis and Mycobacteria Unit, Morne Jolivière, Les Abymes, Guadeloupe, France
| | - Eric Elguero
- Unité Mixte de Recherche Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle Institut de Recherche pour le Développement-Centre National de la Recherche Scientifique-Université de Montpellier, Centre Institut de Recherche pour le Développement de Montpellier, Montpellier, France
| | - Marine Combe
- Unité Mixte de Recherche Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle Institut de Recherche pour le Développement-Centre National de la Recherche Scientifique-Université de Montpellier, Centre Institut de Recherche pour le Développement de Montpellier, Montpellier, France
| | - Camilla J Velvin
- Unité Mixte de Recherche Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle Institut de Recherche pour le Développement-Centre National de la Recherche Scientifique-Université de Montpellier, Centre Institut de Recherche pour le Développement de Montpellier, Montpellier, France
| | - Christine Chevillon
- Unité Mixte de Recherche Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle Institut de Recherche pour le Développement-Centre National de la Recherche Scientifique-Université de Montpellier, Centre Institut de Recherche pour le Développement de Montpellier, Montpellier, France
| | - Alain Berlioz-Arthaud
- Institut Pasteur de la Guyane, Laboratoire de Biologie Médicale, Cayenne, French Guiana
| | - Sylvain Labbé
- Service D'Anatomie-Pathologique, Cayenne Hospital, Cayenne, French Guiana
| | | | - Jean-François Guégan
- Unité Mixte de Recherche Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle Institut de Recherche pour le Développement-Centre National de la Recherche Scientifique-Université de Montpellier, Centre Institut de Recherche pour le Développement de Montpellier, Montpellier, France; Future Earth United Nations International Programme, OneHealth Research Initiative, Montréal, QC, Canada
| | - Roger Pradinaud
- Service de Dermatologie, Cayenne Hospital, Cayenne, French Guiana
| | - Pierre Couppié
- Service de Dermatologie, Cayenne Hospital, Cayenne, French Guiana; Université de Guyane, EA3593 Epidémiologie des Parasitoses Tropicales, Cayenne, French Guiana.
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Combe M, Velvin CJ, Morris A, Garchitorena A, Carolan K, Sanhueza D, Roche B, Couppié P, Guégan JF, Gozlan RE. Global and local environmental changes as drivers of Buruli ulcer emergence. Emerg Microbes Infect 2017; 6:e21. [PMID: 28442755 PMCID: PMC5457673 DOI: 10.1038/emi.2017.7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 01/05/2017] [Accepted: 01/09/2017] [Indexed: 11/21/2022]
Abstract
Many emerging infectious diseases are caused by generalist pathogens that infect and transmit via multiple host species with multiple dissemination routes, thus confounding the understanding of pathogen transmission pathways from wildlife reservoirs to humans. The emergence of these pathogens in human populations has frequently been associated with global changes, such as socio-economic, climate or biodiversity modifications, by allowing generalist pathogens to invade and persist in new ecological niches, infect new host species, and thus change the nature of transmission pathways. Using the case of Buruli ulcer disease, we review how land-use changes, climatic patterns and biodiversity alterations contribute to disease emergence in many parts of the world. Here we clearly show that Mycobacterium ulcerans is an environmental pathogen characterized by multi-host transmission dynamics and that its infectious pathways to humans rely on the local effects of global environmental changes. We show that the interplay between habitat changes (for example, deforestation and agricultural land-use changes) and climatic patterns (for example, rainfall events), applied in a local context, can lead to abiotic environmental changes and functional changes in local biodiversity that favor the pathogen's prevalence in the environment and may explain disease emergence.
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Affiliation(s)
- Marine Combe
- Centre IRD de Montpellier, Département Santé, UMR MIVEGEC IRD-CNRS-Université de Montpellier, 34394 Montpellier, France
| | - Camilla Jensen Velvin
- Centre IRD de Montpellier, Département Santé, UMR MIVEGEC IRD-CNRS-Université de Montpellier, 34394 Montpellier, France
| | - Aaron Morris
- The Royal Veterinary College, Department of Production and Population Health, The Royal Veterinary College, Hawkshead Lane North Mymms, Hatfield, Hertfordshire AL9 7TA, UK
| | - Andres Garchitorena
- Department of Global Health and Social Medicine, Harvard Medical School, Boston, MA 02115, USA
- PIVOT, Division of Global Health Equity, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Kevin Carolan
- Computational & Systems Biology, Rothamsted Research, Harpenden AL5 2JQ, UK
| | - Daniel Sanhueza
- Centre IRD de Montpellier, Département Santé, UMR MIVEGEC IRD-CNRS-Université de Montpellier, 34394 Montpellier, France
| | - Benjamin Roche
- UMMISCO, Département Sociétés et Mondialisation, UMI IRD-UPMC 209, 93143 Bondy, France
| | - Pierre Couppié
- Université de Guyane, EA3593 Epidémiologie des Parasitoses Tropicales, 97306 Cayenne, French Guiana, France
- Service de Dermatologie, Cayenne Hospital, rue des Flamboyant, BP 6006, 97306 Cayenne, French Guiana, France
| | - Jean-François Guégan
- Centre IRD de Montpellier, Département Santé, UMR MIVEGEC IRD-CNRS-Université de Montpellier, 34394 Montpellier, France
- Future Earth International Programme, OneHealth Global Research Project, Future Earth Montréal Hub, Montréal, QC H3H 2L3, Canada
| | - Rodolphe Elie Gozlan
- Institut de Recherche pour le Développement, Département Ecologie, Biodiversité et Fonctionnement des Ecosystemes Continentaux, UMR BOREA IRD 207, CNRS 7208, MNHN, UPMC, Muséum National d'Histoire Naturelle, 75231 Paris, France
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24
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Morris AL, Guégan JF, Andreou D, Marsollier L, Carolan K, Le Croller M, Sanhueza D, Gozlan RE. Deforestation-driven food-web collapse linked to emerging tropical infectious disease, Mycobacterium ulcerans. SCIENCE ADVANCES 2016; 2:e1600387. [PMID: 27957534 PMCID: PMC5142798 DOI: 10.1126/sciadv.1600387] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 11/10/2016] [Indexed: 06/06/2023]
Abstract
Generalist microorganisms are the agents of many emerging infectious diseases (EIDs), but their natural life cycles are difficult to predict due to the multiplicity of potential hosts and environmental reservoirs. Among 250 known human EIDs, many have been traced to tropical rain forests and specifically freshwater aquatic systems, which act as an interface between microbe-rich sediments or substrates and terrestrial habitats. Along with the rapid urbanization of developing countries, population encroachment, deforestation, and land-use modifications are expected to increase the risk of EID outbreaks. We show that the freshwater food-web collapse driven by land-use change has a nonlinear effect on the abundance of preferential hosts of a generalist bacterial pathogen, Mycobacterium ulcerans. This leads to an increase of the pathogen within systems at certain levels of environmental disturbance. The complex link between aquatic, terrestrial, and EID processes highlights the potential importance of species community composition and structure and species life history traits in disease risk estimation and mapping. Mechanisms such as the one shown here are also central in predicting how human-induced environmental change, for example, deforestation and changes in land use, may drive emergence.
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Affiliation(s)
- Aaron L. Morris
- Faculty of Science and Technology, Department of Life and Environmental Sciences, Bournemouth University, Dorset BH12 5BB, UK
- Institut de Recherche pour le Développement, UMR MIVEGEC IRD-CNRS-Université de Montpellier, Centre IRD de Montpellier, BP 64501, Montpellier, France
| | - Jean-François Guégan
- Institut de Recherche pour le Développement, UMR MIVEGEC IRD-CNRS-Université de Montpellier, Centre IRD de Montpellier, BP 64501, Montpellier, France
- International research programme Future Earth, ecoHEALTH initiative, Ottawa, Ontario, Canada
| | - Demetra Andreou
- Faculty of Science and Technology, Department of Life and Environmental Sciences, Bournemouth University, Dorset BH12 5BB, UK
| | - Laurent Marsollier
- Equipe Inserm Avenir ATOMycA, CRCNA INSERM U892 and CNRS U6299, Université et CHU d’Angers, 49933 Angers, France
| | - Kevin Carolan
- Institut de Recherche pour le Développement, UMR MIVEGEC IRD-CNRS-Université de Montpellier, Centre IRD de Montpellier, BP 64501, Montpellier, France
| | - Marie Le Croller
- Institut de Recherche pour le Développement, UMR MIVEGEC IRD-CNRS-Université de Montpellier, Centre IRD de Montpellier, BP 64501, Montpellier, France
| | - Daniel Sanhueza
- Institut de Recherche pour le Développement, UMR MIVEGEC IRD-CNRS-Université de Montpellier, Centre IRD de Montpellier, BP 64501, Montpellier, France
- Equipe Inserm Avenir ATOMycA, CRCNA INSERM U892 and CNRS U6299, Université et CHU d’Angers, 49933 Angers, France
| | - Rodolphe E. Gozlan
- Faculty of Science and Technology, Department of Life and Environmental Sciences, Bournemouth University, Dorset BH12 5BB, UK
- Institut de Recherche pour le Développement, UMR MIVEGEC IRD-CNRS-Université de Montpellier, Centre IRD de Montpellier, BP 64501, Montpellier, France
- Institut de Recherche pour le Développement, UMR BOREA IRD-MNHN-Université Pierre et Marie Curie, Muséum National d’Histoire Naturelle, 47 rue Cuvier, 75231 Paris cedex 5, France
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Burden and Historical Trend of Buruli Ulcer Prevalence in Selected Communities along the Offin River of Ghana. PLoS Negl Trop Dis 2016; 10:e0004603. [PMID: 27078028 PMCID: PMC4831816 DOI: 10.1371/journal.pntd.0004603] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 03/11/2016] [Indexed: 11/21/2022] Open
Abstract
Buruli ulcer (BU) is a neglected tropical skin disease caused by Mycobacterium ulcerans with more than two thirds of the global cases reported in West Africa. A nationwide active BU case search conducted in 1999 identified two health districts along the Offin River as two of the three most endemic districts in Ghana. Based on recent anecdotal accounts that transmission is unstable along the Offin River, we conducted from March to June 2013 an exhaustive household survey and active case search in 13 selected communities within a five-kilometer radius along the Offin River. The overall prevalence of BU was 2.3% among the surveyed population of 20,390 inhabitants and 477 of the total 480 cases detected (99.4%) were historical (healed) cases. By estimating the year of occurrence for each case per community and taking into account available passive surveillance records of health facilities and the District Health Directorate, we observed a general trend of continuous emergence of cases in communities located midstream the Offin River whereas downstream communities showed more sporadic patterns. We monitored the incidence of cases after the survey and recorded a cumulative incidence rate of 0.04% for the 13 communities over a 17-month active surveillance period from August 2013 to December 2014. Our data reveal an overall decline in BU incidence along the Offin River similar to the general decline in BU incidence in recent years reported by the World Health Organization for West Africa. Buruli ulcer (BU) is a tropical skin disease caused by Mycobacterium ulcerans and more than two thirds of the global cases reported in West Africa. The Offin has been considered the most endemic river valley in Ghana following a nationwide active case search conducted in 1999. Here, we present findings of an exhaustive household survey and case search of 13 selected communities along the Offin river aimed at addressing recent anecdotal accounts of unstable transmission of M. ulcerans within the river basin. We observed among the surveyed population of 20,390 inhabitants, an overall 2.3% prevalence of BU with 99.4% of the total cases detected being historical cases. We also observed a general trend of continuous and sporadic emergence of cases in mid and downstream communities, respectively. Subsequently, we detected a total of eight cases (0.04% cumulative incidence rate) in a prospective 17-month active surveillance of all 13 communities. These data confirm the recent decline in BU incidence in historically endemic communities along the Offin river basin, analogous to the observation made in recent years by the World Health Organization for West Africa.
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Landier J, Constantin de Magny G, Garchitorena A, Guégan JF, Gaudart J, Marsollier L, Le Gall P, Giles-Vernick T, Eyangoh S, Fontanet A, Texier G. Seasonal Patterns of Buruli Ulcer Incidence, Central Africa, 2002-2012. Emerg Infect Dis 2016. [PMID: 26196525 PMCID: PMC4517715 DOI: 10.3201/eid2108.141336] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
To determine when risk for Buruli ulcer is highest, we examined seasonal patterns in a highly disease-endemic area of Cameroon during 2002–2012. Cases peaked in March, suggesting that risk is highest during the high rainy season. During and after this season, populations should increase protective behaviors, and case detection efforts should be intensified.
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Tschakert P, Ricciardi V, Smithwick E, Machado M, Ferring D, Hausermann H, Bug L. Situated knowledge of pathogenic landscapes in Ghana: Understanding the emergence of Buruli ulcer through qualitative analysis. Soc Sci Med 2015; 150:160-71. [PMID: 26761375 DOI: 10.1016/j.socscimed.2015.12.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Revised: 09/30/2015] [Accepted: 12/04/2015] [Indexed: 11/28/2022]
Abstract
Successfully addressing neglected tropical diseases requires nuanced understandings of pathogenic landscapes that incorporate situated, contexualized community knowledge. In the case of Buruli ulcer (BU), the role of social science is vital to investigate complex human-environment interactions and navigate different ways of knowing. We analyze a set of qualitative data from our interdisciplinary project on BU in Ghana, drawing from participatory mapping, focus group discussions, semi-structured interviews, and open-ended survey questions to explore how people in endemic and non-endemic areas see themselves embedded in changing environmental and social landscapes. We pay particular attention to landscape disturbance through logging and small-scale alluvial gold mining. The results from our participatory research underscore the holistic nature of BU emergence in landscapes, encapsulated in partial and incomplete local descriptions, the relevance of collective learning to distill complexity, and the potential of rich qualitative data to inform quantitative landscape-disease models.
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Affiliation(s)
- Petra Tschakert
- Department of Geography, Pennsylvania State University, University Park, PA, 16802, USA; Earth and Environmental Systems Institute, Pennsylvania State University, University Park, PA, 16802, USA; School of Earth and Environment, University of Western Australia, M004, Crawley, WA, 6009, Australia.
| | - Vincent Ricciardi
- Department of Geography, Pennsylvania State University, University Park, PA, 16802, USA; Institute for Resources, Environment, and Sustainability (IRES), University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
| | - Erica Smithwick
- Department of Geography, Pennsylvania State University, University Park, PA, 16802, USA; Earth and Environmental Systems Institute, Pennsylvania State University, University Park, PA, 16802, USA.
| | - Mario Machado
- Department of Geography, Pennsylvania State University, University Park, PA, 16802, USA.
| | - David Ferring
- Department of Geography, Rutgers University, Piscataway, NJ, 08854-8045, USA.
| | - Heidi Hausermann
- Department of Human Ecology, Rutgers University, New Brunswick, NJ, 08901-8520, USA.
| | - Leah Bug
- Center for Science and the Schools, Pennsylvania State University, University Park, PA, 16802, USA.
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Wu J, Tschakert P, Klutse E, Ferring D, Ricciardi V, Hausermann H, Oppong J, Smithwick EAH. Buruli Ulcer Disease and Its Association with Land Cover in Southwestern Ghana. PLoS Negl Trop Dis 2015; 9:e0003840. [PMID: 26091265 PMCID: PMC4474842 DOI: 10.1371/journal.pntd.0003840] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 05/19/2015] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Buruli ulcer (BU), one of 17 neglected tropical diseases, is a debilitating skin and soft tissue infection caused by Mycobacterium ulcerans. In tropical Africa, changes in land use and proximity to water have been associated with the disease. This study presents the first analysis of BU at the village level in southwestern Ghana, where prevalence rates are among the highest globally, and explores fine and medium-scale associations with land cover by comparing patterns both within BU clusters and surrounding landscapes. METHODOLOGY/PRINCIPAL FINDINGS We obtained 339 hospital-confirmed BU cases in southwestern Ghana between 2007 and 2010. The clusters of BU were identified using spatial scan statistics and the percentages of six land cover classes were calculated based on Landsat and Rapid Eye imagery for each of 154 villages/towns. The association between BU prevalence and each land cover class was calculated using negative binomial regression models. We found that older people had a significantly higher risk for BU after considering population age structure. BU cases were positively associated with the higher percentage of water and grassland surrounding each village, but negatively associated with the percent of urban. The results also showed that BU was clustered in areas with high percentage of mining activity, suggesting that water and mining play an important and potentially interactive role in BU occurrence. CONCLUSIONS/SIGNIFICANCE Our study highlights the importance of multiple land use changes along the Offin River, particularly mining and agriculture, which might be associated with BU disease in southwestern Ghana. Our study is the first to use both medium- and high-resolution imagery to assess these changes. We also show that older populations (≥ 60 y) appear to be at higher risk of BU disease than children, once BU data were weighted by population age structures.
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Affiliation(s)
- Jianyong Wu
- Department of Geography, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Petra Tschakert
- Department of Geography, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | | | - David Ferring
- Department of Geography, Rutgers University, Piscataway, New Jersey, United States of America
| | - Vincent Ricciardi
- Department of Geography, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Heidi Hausermann
- Department of Human Ecology, Rutgers University, New Brunswick, New Jersey, United States of America
| | - Joseph Oppong
- Department of Geography, The University of North Texas, Denton, Texas, United States of America
| | - Erica A. H. Smithwick
- Department of Geography, The Pennsylvania State University, University Park, Pennsylvania, United States of America
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Ablordey AS, Vandelannoote K, Frimpong IA, Ahortor EK, Amissah NA, Eddyani M, Durnez L, Portaels F, de Jong BC, Leirs H, Porter JL, Mangas KM, Lam MMC, Buultjens A, Seemann T, Tobias NJ, Stinear TP. Whole genome comparisons suggest random distribution of Mycobacterium ulcerans genotypes in a Buruli ulcer endemic region of Ghana. PLoS Negl Trop Dis 2015; 9:e0003681. [PMID: 25826332 PMCID: PMC4380315 DOI: 10.1371/journal.pntd.0003681] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2015] [Accepted: 03/06/2015] [Indexed: 12/01/2022] Open
Abstract
Efforts to control the spread of Buruli ulcer – an emerging ulcerative skin infection caused by Mycobacterium ulcerans - have been hampered by our poor understanding of reservoirs and transmission. To help address this issue, we compared whole genomes from 18 clinical M. ulcerans isolates from a 30km2 region within the Asante Akim North District, Ashanti region, Ghana, with 15 other M. ulcerans isolates from elsewhere in Ghana and the surrounding countries of Ivory Coast, Togo, Benin and Nigeria. Contrary to our expectations of finding minor DNA sequence variations among isolates representing a single M. ulcerans circulating genotype, we found instead two distinct genotypes. One genotype was closely related to isolates from neighbouring regions of Amansie West and Densu, consistent with the predicted local endemic clone, but the second genotype (separated by 138 single nucleotide polymorphisms [SNPs] from other Ghanaian strains) most closely matched M. ulcerans from Nigeria, suggesting another introduction of M. ulcerans to Ghana, perhaps from that country. Both the exotic genotype and the local Ghanaian genotype displayed highly restricted intra-strain genetic variation, with less than 50 SNP differences across a 5.2Mbp core genome within each genotype. Interestingly, there was no discernible spatial clustering of genotypes at the local village scale. Interviews revealed no obvious epidemiological links among BU patients who had been infected with identical M. ulcerans genotypes but lived in geographically separate villages. We conclude that M. ulcerans is spread widely across the region, with multiple genotypes present in any one area. These data give us new perspectives on the behaviour of possible reservoirs and subsequent transmission mechanisms of M. ulcerans. These observations also show for the first time that M. ulcerans can be mobilized, introduced to a new area and then spread within a population. Potential reservoirs of M. ulcerans thus might include humans, or perhaps M. ulcerans-infected animals such as livestock that move regularly between countries. In this study we use the power of whole genome sequence comparisons to track the spread of Mycobacterium ulcerans, the causative agent of Buruli ulcer, through several villages in the Ashanti region of Ghana, providing new insights on the behaviour of this enigmatic and emerging pathogen.
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Affiliation(s)
- Anthony S. Ablordey
- Department of Bacteriology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
- * E-mail: (ASA); (TPS)
| | - Koen Vandelannoote
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Isaac A. Frimpong
- Department of Animal Biology and Conservation Science, University of Ghana, Accra, Ghana
| | - Evans K. Ahortor
- Department of Bacteriology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Nana Ama Amissah
- Department of Bacteriology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Miriam Eddyani
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Lies Durnez
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Françoise Portaels
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Bouke C. de Jong
- Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Herwig Leirs
- Department of Biology, University of Antwerp, Antwerp, Belgium
| | - Jessica L. Porter
- Department of Microbiology and Immunology, University of Melbourne, Parkville, Australia
| | - Kirstie M. Mangas
- Department of Microbiology and Immunology, University of Melbourne, Parkville, Australia
| | - Margaret M. C. Lam
- Department of Microbiology and Immunology, University of Melbourne, Parkville, Australia
| | - Andrew Buultjens
- Department of Microbiology and Immunology, University of Melbourne, Parkville, Australia
| | - Torsten Seemann
- Life Sciences Computation Centre, Victorian Life Sciences Computation Initiative, Carlton, Victoria, Australia
| | - Nicholas J. Tobias
- Department of Microbiology and Immunology, University of Melbourne, Parkville, Australia
| | - Timothy P. Stinear
- Department of Microbiology and Immunology, University of Melbourne, Parkville, Australia
- * E-mail: (ASA); (TPS)
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Carolan K, Garchitorena A, García-Peña GE, Morris A, Landier J, Fontanet A, Le Gall P, Texier G, Marsollier L, Gozlan RE, Eyangoh S, Lo Seen D, Guégan JF. Topography and land cover of watersheds predicts the distribution of the environmental pathogen Mycobacterium ulcerans in aquatic insects. PLoS Negl Trop Dis 2014; 8:e3298. [PMID: 25375173 PMCID: PMC4222759 DOI: 10.1371/journal.pntd.0003298] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 09/25/2014] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND An understanding of the factors driving the distribution of pathogens is useful in preventing disease. Often we achieve this understanding at a local microhabitat scale; however the larger scale processes are often neglected. This can result in misleading inferences about the distribution of the pathogen, inhibiting our ability to manage the disease. One such disease is Buruli ulcer, an emerging neglected tropical disease afflicting many thousands in Africa, caused by the environmental pathogen Mycobacterium ulcerans. Herein, we aim to describe the larger scale landscape process describing the distribution of M. ulcerans. METHODOLOGY Following extensive sampling of the community of aquatic macroinvertebrates in Cameroon, we select the 5 dominant insect Orders, and conduct an ecological niche model to describe how the distribution of M. ulcerans positive insects changes according to land cover and topography. We then explore the generalizability of the results by testing them against an independent dataset collected in a second endemic region, French Guiana. PRINCIPAL FINDINGS We find that the distribution of the bacterium in Cameroon is accurately described by the land cover and topography of the watershed, that there are notable seasonal differences in distribution, and that the Cameroon model does not predict the distribution of M. ulcerans in French Guiana. CONCLUSIONS/SIGNIFICANCE Future studies of M. ulcerans would benefit from consideration of local structure of the local stream network in future sampling, and further work is needed on the reasons for notable differences in the distribution of this species from one region to another. This work represents a first step in the identification of large-scale environmental drivers of this species, for the purposes of disease risk mapping.
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Affiliation(s)
- Kevin Carolan
- Unité mixte de recherche (UMR) Maladies Infectieuses et Vecteurs: Écologie, Génétique, Evolution, et Contrôle (MIVEGEC) IRD-CNRS-Universities of Montpellier I and II, Centre IRD de Montpellier, Montpellier, France
- UMR Territoires, Environnement, Télédétection et Information Spatiale (TETIS) CIRAD, Montpellier, France
- Unité d'Epidémiologie de Maladies Emergentes, Institut Pasteur, Paris, France
| | - Andres Garchitorena
- Unité mixte de recherche (UMR) Maladies Infectieuses et Vecteurs: Écologie, Génétique, Evolution, et Contrôle (MIVEGEC) IRD-CNRS-Universities of Montpellier I and II, Centre IRD de Montpellier, Montpellier, France
- Ecole des Hautes Etudes en Santé Publique, Rennes, France
| | - Gabriel E. García-Peña
- Unité mixte de recherche (UMR) Maladies Infectieuses et Vecteurs: Écologie, Génétique, Evolution, et Contrôle (MIVEGEC) IRD-CNRS-Universities of Montpellier I and II, Centre IRD de Montpellier, Montpellier, France
- Centre de Synthèse et d'Analyse sur la Biodiversité -CESAB. Bâtiment Henri Poincaré, Domaine du Petit Arbois. Aix-en-Provence, France
| | - Aaron Morris
- Unité mixte de recherche (UMR) Maladies Infectieuses et Vecteurs: Écologie, Génétique, Evolution, et Contrôle (MIVEGEC) IRD-CNRS-Universities of Montpellier I and II, Centre IRD de Montpellier, Montpellier, France
- Bournemouth University, School of Applied Sciences, Dorset, United Kingdom
| | - Jordi Landier
- Unité d'Epidémiologie de Maladies Emergentes, Institut Pasteur, Paris, France
- Service d'épidémiologie et de santé publique, Centre Pasteur du Cameroun, Réseau International des Instituts Pasteur, Yaoundé, Cameroun
| | - Arnaud Fontanet
- Unité d'Epidémiologie de Maladies Emergentes, Institut Pasteur, Paris, France
- Chaire Santé et Développement, Conservatoire National des Arts et Métiers, Paris, France
| | - Philippe Le Gall
- Institut de Recherche pour le Développement (IRD), UR 072, Laboratoire Evolution, Génomes et Spéciation, UPR 9034, Centre National de la Recherche Scientifique (CNRS), Gif sur Yvette, France et Université Paris-Sud 11, Orsay, France
| | - Gaëtan Texier
- Service d'épidémiologie et de santé publique, Centre Pasteur du Cameroun, Réseau International des Instituts Pasteur, Yaoundé, Cameroun
- UMR 912 - SESSTIM - INSERM/IRD/Aix-Marseille Université Faculté de Médecine - 27, Marseille, France
| | - Laurent Marsollier
- ATOMycA, Inserm Avenir Team, CRCNA, Inserm U892, 6299 CNRS and LUNAM, Angers, France
| | - Rodolphe E. Gozlan
- Unité mixte de recherche (UMR) Maladies Infectieuses et Vecteurs: Écologie, Génétique, Evolution, et Contrôle (MIVEGEC) IRD-CNRS-Universities of Montpellier I and II, Centre IRD de Montpellier, Montpellier, France
- Bournemouth University, School of Applied Sciences, Dorset, United Kingdom
- UMR 207 BOREA IRD-MNHN-Université Pierre et Marie Curie, Muséum National d'Histoire Naturelle, Paris, France
| | - Sara Eyangoh
- Service de Mycobactériologie, Centre Pasteur du Cameroun, Réseau International des Instituts Pasteur, Yaoundé, Cameroun
| | - Danny Lo Seen
- UMR Territoires, Environnement, Télédétection et Information Spatiale (TETIS) CIRAD, Montpellier, France
| | - Jean-Francois Guégan
- Unité mixte de recherche (UMR) Maladies Infectieuses et Vecteurs: Écologie, Génétique, Evolution, et Contrôle (MIVEGEC) IRD-CNRS-Universities of Montpellier I and II, Centre IRD de Montpellier, Montpellier, France
- Ecole des Hautes Etudes en Santé Publique, Rennes, France
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Carolan K, Ebong SMA, Garchitorena A, Landier J, Sanhueza D, Texier G, Marsollier L, Gall PL, Guégan JF, Lo Seen D. Ecological niche modelling of Hemipteran insects in Cameroon; the paradox of a vector-borne transmission for Mycobacterium ulcerans, the causative agent of Buruli ulcer. Int J Health Geogr 2014; 13:44. [PMID: 25344052 PMCID: PMC4213541 DOI: 10.1186/1476-072x-13-44] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2014] [Accepted: 10/13/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The mode of transmission of the emerging neglected disease Buruli ulcer is unknown. Several potential transmission pathways have been proposed, such as amoebae, or transmission through food webs. Several lines of evidence have suggested that biting aquatic insects, Naucoridae and Belostomatidae, may act as vectors, however this proposal remains controversial. MATERIALS AND METHODS Herein, based on sampling in Cameroon, we construct an ecological niche model of these insects to describe their spatial distribution. We predict their distribution across West Africa, describe important environmental drivers of their abundance, and examine the correlation between their abundance and Buruli ulcer prevalence in the context of the Bradford-Hill guidelines. RESULTS We find a significant positive correlation between the abundance of the insects and the prevalence of Buruli ulcer. This correlation changes in space and time, it is significant in one Camerounese study region in (Akonolinga) and not other (Bankim). We discuss notable environmental differences between these regions. CONCLUSION We interpret the presence of, and change in, this correlation as evidence (though not proof) that these insects may be locally important in the environmental persistence, or transmission, of Mycobacterium. ulcerans. This is consistent with the idea of M. ulcerans as a pathogen transmitted by multiple modes of infection, the importance of any one pathway changing from region to region, depending on the local environmental conditions.
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Affiliation(s)
- Kevin Carolan
- Unité mixte de recherche (UMR) Maladies Infectieuses et Vecteurs : Écologie, Génétique, Evolution, et Contrôle (MIVEGEC) IRD-CNRS-Universities of Montpellier I and II, Centre IRD de Montpellier, BP 64501, 34394 Montpellier Cedex 5, France.
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Landier J, Gaudart J, Carolan K, Lo Seen D, Guégan JF, Eyangoh S, Fontanet A, Texier G. Spatio-temporal patterns and landscape-associated risk of Buruli ulcer in Akonolinga, Cameroon. PLoS Negl Trop Dis 2014; 8:e3123. [PMID: 25188464 PMCID: PMC4154661 DOI: 10.1371/journal.pntd.0003123] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 07/17/2014] [Indexed: 11/18/2022] Open
Abstract
Background Buruli ulcer (BU) is an extensively damaging skin infection caused by Mycobacterium ulcerans, whose transmission mode is still unknown. The focal distribution of BU and the absence of interpersonal transmission suggest a major role of environmental factors, which remain unidentified. This study provides the first description of the spatio-temporal variations of BU in an endemic African region, in Akonolinga, Cameroon. We quantify landscape-associated risk of BU, and reveal local patterns of endemicity. Methodology/Principal Findings From January 2002 to May 2012, 787 new BU cases were recorded in 154 villages of the district of Akonolinga. Incidence per village ranged from 0 (n = 59 villages) to 10.4 cases/1000 person.years (py); median incidence was 0.4 cases/1,000py. Villages neighbouring the Nyong River flood plain near Akonolinga town were identified as the highest risk zone using the SPODT algorithm. We found a decreasing risk with increasing distance to the Nyong and identified 4 time phases with changes in spatial distribution. We classified the villages into 8 groups according to landscape characteristics using principal component analysis and hierarchical clustering. We estimated the incidence ratio (IR) associated with each landscape using a generalised linear model. BU risk was highest in landscapes with abundant wetlands, especially cultivated ones (IR = 15.7, 95% confidence interval [95%CI] = 15.7[4.2–59.2]), and lowest in reference landscape where primary and secondary forest cover was abundant. In intermediate-risk landscapes, risk decreased with agriculture pressure (from IR[95%CI] = 7.9[2.2–28.8] to 2.0[0.6–6.6]). We identified landscapes where endemicity was stable and landscapes where incidence increased with time. Conclusion/Significance Our study on the largest series of BU cases recorded in a single endemic region illustrates the local evolution of BU and identifies the Nyong River as the major driver of BU incidence. Local differences along the river are explained by wetland abundance and human modification of the environment. Buruli ulcer (BU) remains a mysterious disease without efficient prevention since the mode of transmission of its agent, Mycobacterium ulcerans, is still unknown. The disease is highly localised within countries and even at the village scale within endemic regions, but environmental factors explaining this focal distribution have not been described yet. In this article, we rely on a large series of cases originating from Akonolinga region, Centre region, Cameroon, and recorded at the BU treatment center of the hospital of Akonolinga. The series of 787 patients over 10 years allows us to describe the distribution of BU incidence in the region and its changes over time and space. We identify the Nyong River as a major risk factor, and identify environmental factors along the river that further increase the risk of BU, such as the high proportion of swamps, the degradation of forests and cultivation of lands by human populations. These results will help to locate where the transmission is most likely to happen, and provide useful elements for targeting case search, prevention actions and future research on M. ulcerans transmission.
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Affiliation(s)
- Jordi Landier
- Institut Pasteur, Unité de Recherche et d'expertise en Epidémiologie des Maladies Emergentes, Paris, France
- Service d'Epidémiologie et de Santé Publique, Centre Pasteur du Cameroun, Réseau International des Instituts Pasteur, Yaoundé, Cameroon
- * E-mail:
| | - Jean Gaudart
- Aix-Marseille Université, UMR912 SESSTIM (INSERM - IRD - AMU), Marseille, France
| | - Kevin Carolan
- UMR MIVEGEC 5290 CNRS - IRD - Université de Montpellier I - Université de Montpellier II, Montpellier, France
| | | | - Jean-François Guégan
- UMR MIVEGEC 5290 CNRS - IRD - Université de Montpellier I - Université de Montpellier II, Montpellier, France
| | - Sara Eyangoh
- Service de Mycobactériologie, Centre Pasteur du Cameroun, Réseau International des Instituts Pasteur, Yaoundé, Cameroon
| | - Arnaud Fontanet
- Institut Pasteur, Unité de Recherche et d'expertise en Epidémiologie des Maladies Emergentes, Paris, France
- Chaire Santé et Développement, Conservatoire National des Arts et Métiers, Paris, France
| | - Gaëtan Texier
- Service d'Epidémiologie et de Santé Publique, Centre Pasteur du Cameroun, Réseau International des Instituts Pasteur, Yaoundé, Cameroon
- Aix-Marseille Université, UMR912 SESSTIM (INSERM - IRD - AMU), Marseille, France
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A theoretical model for the transmission dynamics of the Buruli ulcer with saturated treatment. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2014; 2014:576039. [PMID: 25214885 PMCID: PMC4158283 DOI: 10.1155/2014/576039] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Revised: 08/05/2014] [Accepted: 08/06/2014] [Indexed: 11/17/2022]
Abstract
The management of the Buruli ulcer (BU) in Africa is often accompanied by limited resources, delays in treatment, and macilent capacity in medical facilities. These challenges limit the number of infected individuals that access medical facilities. While most of the mathematical models with treatment assume a treatment function proportional to the number of infected individuals, in settings with such limitations, this assumption may not be valid. To capture these challenges, a mathematical model of the Buruli ulcer with a saturated treatment function is developed and studied. The model is a coupled system of two submodels for the human population and the environment. We examine the stability of the submodels and carry out numerical simulations. The model analysis is carried out in terms of the reproduction number of the submodel of environmental dynamics. The dynamics of the human population submodel, are found to occur at the steady states of the submodel of environmental dynamics. Sensitivity analysis is carried out on the model parameters and it is observed that the BU epidemic is driven by the dynamics of the environment. The model suggests that more effort should be focused on environmental management. The paper is concluded by discussing the public implications of the results.
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Complex temporal climate signals drive the emergence of human water-borne disease. Emerg Microbes Infect 2014; 3:e56. [PMID: 26038751 PMCID: PMC4150285 DOI: 10.1038/emi.2014.56] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 06/03/2014] [Accepted: 06/16/2014] [Indexed: 12/18/2022]
Abstract
Predominantly occurring in developing parts of the world, Buruli ulcer is a severely disabling mycobacterium infection which often leads to extensive necrosis of the skin. While the exact route of transmission remains uncertain, like many tropical diseases, associations with climate have been previously observed and could help identify the causative agent's ecological niche. In this paper, links between changes in rainfall and outbreaks of Buruli ulcer in French Guiana, an ultraperipheral European territory in the northeast of South America, were identified using a combination of statistical tests based on singular spectrum analysis, empirical mode decomposition and cross-wavelet coherence analysis. From this, it was possible to postulate for the first time that outbreaks of Buruli ulcer can be triggered by combinations of rainfall patterns occurring on a long (i.e., several years) and short (i.e., seasonal) temporal scale, in addition to stochastic events driven by the El Niño-Southern Oscillation that may disrupt or interact with these patterns. Long-term forecasting of rainfall trends further suggests the possibility of an upcoming outbreak of Buruli ulcer in French Guiana.
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Eric Benbow M, Kimbirauskas R, McIntosh MD, Williamson H, Quaye C, Boakye D, Small PLC, Merritt RW. Aquatic macroinvertebrate assemblages of Ghana, West Africa: understanding the ecology of a neglected tropical disease. ECOHEALTH 2014; 11:168-183. [PMID: 24306551 DOI: 10.1007/s10393-013-0886-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Revised: 10/03/2013] [Accepted: 10/05/2013] [Indexed: 06/02/2023]
Abstract
Buruli ulcer (BU) is an emerging, but neglected tropical disease, where there has been a reported association with disturbed aquatic habitats and proposed aquatic macroinvertebrate vectors such as biting Hemiptera. An initial step in understanding the potential role of macroinvertebrates in the ecology of BU is to better understand the entire community, not just one or two taxa, in relation to the pathogen, Mycobacterium ulcerans, at a large spatial scale. For the first time at a country-wide scale this research documents that M. ulcerans was frequently detected from environmental samples taken from BU endemic regions, but was not present in 30 waterbodies of a non-endemic region. There were significant differences in macroinvertebrate community structure and identified potential indicator taxa in relation to pathogen presence. These results suggest that specific macroinvertebrate taxa or functional metrics may potentially be used as aquatic biological indicators of M. ulcerans. Developing ecological indicators of this pathogen is a first step for understanding the disease ecology of BU and should assist future studies of transmission.
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Affiliation(s)
- M Eric Benbow
- Department of Entomology, Michigan State University, East Lansing, MI, 48824, USA,
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