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International audience; Monkeypox (MPX) is an emergent severe zoonotic disease resembling that of smallpox. To date, most cases of humanMPX have been reported in the Democratic Republic of the Congo (DRC).While the number of cases has increased steadily in the DRC over the last 30 years, the environmental risk factors that drive the spatiotemporal dynamics of MPX transmission remain poorly understood. This study aimed to investigate the spatiotemporal associations between environmental risk factors and annual MPX incidence in the DRC. All MPX cases reported weekly at the health zone level over a 16-year period (2000-2015) were analyzed. A Bayesian hierarchical generalized linear mixed model was conducted to identify the spatiotemporal associations between annual MPX incidence and three types of environmental risk factors illustrating environment as a system resulting from physical, social and cultural interactions Primary forest (IRR 1.034 [1.029-1.040]), economic well-being (IRR 1.038 [1.031-1.047]), and temperature (IRR 1.143 [1.028-1.261]) werepositively associated with annual MPX incidence. Our study shows that physical environmental risk factors alone cannot explain the emergence of MPX outbreaks in the DRC. Economic level and cultural practices participate from environment as a whole and thus, must be considered to understand exposure to MPX risk Future studies should examine the impact of these factors in greater detail.

Describing patterns and testing hypotheses on processes driving biological invasions represent major issues in ecology. Addressing these questions requires building adequate data sets, i.e., covering areas and spanning periods adapted to the invasion processes studied. Rodents include major invasive species, among which the black rat Rattus rattus and the domestic mouse Mus musculus have nearly colonized the entire world, from their native Asian range. To do so, they have benefitted from their ability to cope with human-modified environments and to live in the immediate vicinity of Man, who served as a vector of their dispersal between regions and continents. In Senegal, both R. rattus and M. musculus, initially introduced by early West European colonizers some centuries ago, are currently expanding thanks to road traffic and infrastructure development and rampant urbanization that concerns even remote regions of the country. As part of projects aimed at studying (1) the role of invasive black rat populations in the emergence of zoonotic diseases in southeastern Senegal, and (2) the evolutionary consequences of parasites in R. rattus and M. musculus invasions in Senegal, we conducted a series of field campaigns throughout the southern half of the country, between May 2012 and September 2015. The objectives were to catch commensal small mammals using standard trapping procedures, identify them using morphological or molecular tools, and take samples from them upon autopsy, to look for zoonotic parasites and pathogens. Along with data on individual specimens, information on microhabitats was gathered at each trap position. This resulted in the constitution of a data set of more than 13,000 trapnights, which allowed the capture of more than 3,100 small mammals, all characterized by a series of associated biological, geographical, and environmental data. The small mammals concerned are mainly rodents (10 species), shrews, and hedgehogs. The two invasive rodent species were the most numerous, exceeding in numbers all the other species pooled. This data set makes it possible to study coarse to fine-scaled distribution of species of this commensal community in southern Senegal, as well as the possible determinants of this distribution in terms of habitat preferences and/or interspecific interactions. This data set can be freely used for non-commercial purposes and is licensed under a Creative Commons Attribution 4.0 International License.

Background The Integrated Disease Surveillance and Response (IDSR) strategy implemented by the World Health Organization (WHO) in Africa has produced a large amount of data on participating countries, and in particular on the Democratic Republic of Congo (DRC). These data are increasingly considered as unevaluable and, therefore, as requiring a rigorous process of validation before they can be used for research or public health purposes. The aim of this study was to propose a method to assess the level of adequacy of IDSR morbidity data in reflecting actual morbidity. Methods A systematic search of English- and French-language articles was performed in Scopus, Medline, Science Direct, Springer Link, Cochrane, Cairn, Persée, and Erudit databases. Other types of documents were identified through manual searches. Selected articles focused on the determinants of the discrepancies (differences) between reported morbidity and actual morbidity. An adequacy score was constructed using some of the identified determinants. This score was applied to the 15 weekly reported diseases monitored by IDSR surveillance in the DRC. A classification was established using the Jenks method and a sensitivity analysis was performed. Twenty-three classes of determinants were identified in 35 IDSR technical guides and reports of outbreak investigations and in 71 out of 2254 researched articles. For each of the 15 weekly reported diseases, the SIA was composed of 12 items grouped in 6 dimensions. Results The SIA classified the 15 weekly reported diseases into 3 categories or types: high score or good adequacy (value > = 14), moderate score or fair adequacy (value > = 8 and

No Brasil em 2015, foi constatada uma disseminação do vírus Zika, acompanhado do aumento de relatos de casos de recém-nascidos com microcefalia e outros distúrbios neurológicos causadas pelo vírus, levantando o debate sobre as dificuldades de acesso aos cuidados de crianças acometidas por infecções intrauterinas, denominadas Síndrome Congênita da Zika e STORCH. As repercussões na saúde infantil se espalharam por todas as regiões brasileiras, sendo as regiões Nordeste e Sudeste do Brasil as mais atingidas, desafiando-nos a compreender o acesso aos cuidados em saúde dessas crianças. O objetivo deste artigo é caracterizar o acesso e a mobilidade aos serviços de saúde e às atividades de estimulação precoce por crianças com Síndrome Congênita por Zika e STORCH, no Distrito Federal – Brasil. A metodologia consistiu no mapeamento dos casos de Síndrome Congênita por Zika e STORCH e das unidades de reabilitação e estimulação precoce, no período entre 2015 e 2017. Como resultado, verificou-se que as crianças com Síndrome Congênita, usuárias do serviço público de saúde, necessitam percorrer longas distâncias para ter acesso às unidades de reabilitação e estimulação precoce em unidades de saúde, enquanto para as unidades de educação, o deslocamento realizado é menor. No geral, nossos resultados evidenciam a dificuldade de execução de políticas de saúde para a estimulação precoce e o importante papel desempenhado pela educação nas atividades de educação precoce no Distrito Federal – Brasil.

International audience; Hantaviruses (family Hantaviridae, genus Ortho-hantavirus) are RNA viruses transmitted by aero-solized excreta from infected rodents and shrews. In humans, they cause hemorrhagic fever with renal syndrome (more often observed in Asia and Europe) and cardiopulmonary syndrome (more common in the Americas) (1). Only 1 case has been confirmed in Africa, in the Central African Republic in 1987 (2). However, studies from 2006 through 2013 have discovered new hantaviruses in autochthonous African rodents, moles, and bats (3,4). In addition, serologic evidence in humans and rodents in Africa suggest local circulation (5). For example, a study in rural areas of Senegal found 11.5% of rodents and 16.6% of humans had antibodies against hantaviruses (3). More recently, serologic evidence of hantaviruses was reported in domestic and peridomestic rodents from some regions in Senegal (6). Southeastern Senegal has become a major trade area because of urbanization and substantial improvement of its road and rail networks in the late 1990s (7). Within a few years, these changes led to the rapid spread of a major invasive rodent species, the black rat (Rattus rattus [family Murinae]), which is a reservoir for Seoul orthohantavirus (SEOV) (4,5,7). To assess the prevalence of hantaviruses in rodents, we screened for hantaviruses in R. rattus rats and commensal or peridomestic co-existing rodents in 2012–2013, approximately 15 years after the 1998 opening of a tarred road in eastern Senegal.

International audience; The mesoniviruses (MESOVs) belong to the newly described Mesoniviridae family (Order: Nidovirales). They have never been reported in Senegal until recently during a study in arbovirus emergence with the detection of a new species of MESOV named Dianke virus (DKV) from common mosquitoes from eastern Senegal. Actually, their vector competence for this newly described DKV is unknown. We, therefore, estimated the vector competence of Culex tritaeniorhynchus, Culex quinquefasciatus, Aedes aegypti, and Anopheles gambiae mosquitoes collected in Senegal for DKV using oral infection. Whole bodies, legs/wings, and saliva samples were tested for DKV by RT-PCR to estimate infection, dissemination, and transmission rates. The infectivity of virus particles in the saliva was confirmed by infecting C6/36 cells. Virus transmission rates were up to 95.45% in Culex tritaeniorhynchus, 28% in Cx. quinquefasciatus and 9.09% in Aedes aegypti. Viral particles in the saliva were confirmed infectious by C6/36 cell culture. An. gambiae was able to disseminate DKV only at 20 days post-infection. This study shows that Culex mosquitoes are more competent than Ae. aegypti for DKV, while Anopheles gambiae is not likely a competent vector.

International audience; To date, there is no effective treatment to cure dengue fever, a mosquito-borne disease which has a major impact on human populations in tropical and subtropical regions. Although the characteristics of dengue infection are well known, factors associated with landscape are highly scale dependent in time and space, and therefore difficult to monitor. We propose here a mapping review based on 78 articles that study the relationships between landscape factors and urban dengue cases considering household, neighborhood and administrative levels. Landscape factors were retrieved from survey questionnaires, Geographic Information Systems (GIS), and remote sensing (RS) techniques. We structured these into groups composed of land cover, land use, and housing type and characteristics, as well as subgroups referring to construction material, urban typology, and infrastructure level. We mapped the co-occurrence networks associated with these Remote Sens. 2020, 12, 932 2 of 82 factors, and analyzed their relevance according to a three-valued interpretation (positive, negative, non significant). From a methodological perspective, coupling RS and GIS techniques with field surveys including entomological observations should be systematically considered, as none digital land use or land cover variables appears to be an univocal determinant of dengue occurrences. Remote sensing urban mapping is however of interest to provide a geographical frame to distribute human population and movement in relation to their activities in the city, and as spatialized input variables for epidemiological and entomological models.

International audience; A major forthcoming sanitary issue concerns the apparition and spreading of drug-resistant microorganisms, potentially threatening millions of humans. In low-income countries, polluted urban runoff and open sewage channels are major sources of microbes. These microbes join natural microbial communities in aquatic ecosystems already impacted by various chemicals, including antibiotics. These composite microbial communities must adapt to survive in such hostile conditions, sometimes promoting the selection of antibiotic-resistant microbial strains by gene transfer. The low probability of exchanges between planktonic microorganisms within the water column may be significantly improved if their contact was facilitated by particular meeting places. This could be specifically the case within biofilms that develop on the surface of the myriads of floating macroplastics increasingly polluting urban tropical surface waters. Moreover, as uncultivable bacterial strains could be involved, analyses of the microbial communities in their whole have to be performed. This means that new-omic technologies must be routinely implemented in low- and middle-income countries to detect the appearance of resistance genes in microbial ecosystems, especially when considering the new 'plastic context.'We summarize the related current knowledge in this short review paper to anticipate new strategies for monitoring and surveying microbial communities.

Monkeypox is a viral disease with a clinical presentation resembling that of smallpox. Although monkeypox is considered to be an important zoonotic viral disease, its epidemiology remains poorly understood, especially the spatial and temporal distribution of the disease. The present study examined weekly reports of monkeypox cases collected from 2000 to 2015 at the health zone scale in the Democratic Republic of Congo. SaTScan® was performed to identify spatial and temporal clusters of monkeypox cases. Significant primary spatial clusters were detected in the districts of Sankuru and Tshuapa. A centrifugal pattern was found, with significant primary spatial clusters extending over time from Sankuru and Tshuapa to several neighboring districts. Peaks of cases occurred from July to September for the 2000-2002 and 2003-2009 sub-periods and from January to March for the 2010-2015 sub-period. Despite the lack of additional data for confirmation, the increasing of monkeypox reported incidence was observed in the Democratic Republic of Congo during 2000-2015 period and this increase cannot be explain only by the improvements of surveillance systems. The detected spatial clusters were located in the dense rainforest of the Congo basin. The reasons for the excess incidence of monkeypox cases in the central region of the country are unknown, and the relative influence of ecological, environmental, and human factors on the mechanism of emergence of monkeypox has yet to be identified.

Les maladies à transmission vectorielle constituent une menace sans cesse renouvelée pour la santé humaine. Adaptation des vecteurs, changement climatique, transformation des environnements, mondialisation des échanges, urbanisation, favorisent le maintien voire l’émergence et la diffusion de ces risques infectieux. Au Brésil, l’actualité se focalise autour des arboviroses transmises par les Aedes aegypti, le pays étant confronté à l’essor aussi bien de la dengue, du Zika, que du Chikungunya et la persistance de la fièvre jaune. D’autres maladies vectorielles se maintiennent comme les schistosomoses, autour des périmètres irrigués du rio São Francisco. La dynamique spatiale de ces pathologies souligne le rôle de la structuration des espaces, du fonctionnement des réseaux, de l’essor de l’urbanisation, de l’offre de soins, faisant écho à des études menées autour des maladies vectorielles, en d’autres lieux et sur d’autres continents. En rappelant les enseignements géographiques issus de quelques travaux interdisciplinaires, nous proposons de renouveler le regard porté sur les maladies vectorielles par des confrontations d’expériences de part et d’autre de l’Atlantique, voire des frontières sud-américaines. As doenças transmitidas por vetores constituem uma ameaça incessantemente renovada para a saúde humana. Adaptação dos vetores, mudanças climáticas, transformação do meio ambiente, mundialização das trocas e urbanização, favorecem a manutenção ou mesmo a emergência e a propagação destes riscos infecciosos. No Brasil, a atenção atualmente se focaliza em torno das arboviroses transmitidas pelo Aedes aegypti, o país é confrontado ao incremento igualmente da Dengue, da Zika e do Chikungunya e a persistência da Febre Amarela. Outras doenças transmitidas por vetores persistem como a esquistossomose no entorno dos perímetros irrigados do Rio São Francisco. A dinâmica espacial destas patologias destaca o papel da estruturação dos espaços, do funcionamento das redes, do desenvolvimento da urbanização, da oferta dos cuidados a saúde, fazendo eco a estudos efetuados ao redor destas mesmas patologias, mas igualmente a outras doenças vetoriais, em outros lugares e em outros continentes. Recordando os ensinos geográficos procedentes de trabalhos interdisciplinares, propomos renovar o olhar sobre as doenças transmitida por vetores por meio das confrontações de experiência de um lado e outro do Atlântico ou mesmo das fronteiras sul-americanas. Vector-borne diseases are a constantly renewed threat to human health. Vectors adaptation, climate change, environment modifications, globalization, urbanization, promote the persistence or even the emergence and diffusion of these infectious risks. In Brazil, today’s preoccupations are focused on Aedes transmitted arboviruses. The country is facing the rise of dengue, Zika, Chikungunya and the persistence of yellow fever. Other vector-borne diseases such as schistosomiasis, persist around the irrigated perimeters of Sao Francisco River. The spatial dynamics of these diseases underline the role of the structuring of spaces, the functioning of networks, the growth of urbanization, and the supply of care, echoing studies carried out around vector-borne diseases, in other places and on other continents. By recalling the geographical teachings resulting from some interdisciplinary work examples, we propose to renew the focus on vector-borne diseases by confronting experiences on both sides of the Atlantic, or even then South American borders.

International audience; This article seeks to recover the origins of health geography, from the production of the first disease maps to the incorporation of new spatial analysis techniques in the last decades. This evolution has also been accompanied by a profound review of paradigms, theories and methods, with a greater emphasis on the relationship between man and the environment, and with approaches that relate socio-spatial structure to health problems at the various scales where they manifest themselves. The current health geography is confronted with the need to articulate the association between the health-disease process and the disease-care binomial, in search of equity, prevention of diseases and diseases and health promotion.; Cet article cherche à retrouver les origines de la géographie de la santé, depuis la production des premières cartes des maladies jusqu'à l'incorporation de nouvelles techniques d'analyse spatiale au cours des dernières décennies. Cette évolution s'est également accompagnée d'une révision en profondeur des paradigmes, des théories et des méthodes, en mettant davantage l'accent sur la relation entre l'homme et l'environnement, et avec des approches qui relient la structure socio-spatiale aux problèmes de santé aux différentes échelles où ils se manifestent. La géographie actuelle de la santé est confrontée à la nécessité d'articuler l'association entre le processus santé-maladie et le binôme maladie-attention, à la recherche de l'équité, de la prévention des maladies et des maladies et de la promotion de la santé.; Este artigo busca resgatar as origens da geografia da saúde, desde a produção dos primeiros mapas de doenças até a incorporação de novas técnicas de análise espacial nas últimas décadas. Esta evolução também foi acompanhada por uma profunda revisão de paradigmas, teorias e métodos, ora com maior ênfase nas relações entre homem e ambiente, ora com abordagens que relacionam a estrutura socioespacial com os problemas de saúde nas diversas escalas em que estes se manifestam. A geografia da saúde atual se defronta com a necessidade de se articular a associação entre o processo de saúde-doença com o binômio doença-atenção, em busca da equidade, da prevenção de doenças e agravos e da promoção da saúde.

L’espace CEDEAO subit de profondes mutations spatiales liees a une forte croissance demographique, au changement climatique et a une croissance economique exceptionnelle. Entre 1950 et 2015, cet espace a accueilli 280 millions nouveaux habitants, soit une moyenne de 4,3 millions nouveaux arrivants par an, parmi lesquels 2,4 millions nouveaux urbains et 1,9 millions nouveaux ruraux. Les dynamiques de peuplements impulsees par ces forces demographiques, climatiques et economiques, s’effectuent parfois en direction des terres neuves parmi lesquelles les espaces proteges. Ces derniers constituent des reserves de biodiversite qui hebergent des reservoirs de pathogenes et d’insectes vecteurs. L’homme, en exploitant ces nouveaux territoires, s’exposent donc a la piqure d’insectes vecteurs de maladies ou au contact d’animaux reservoirs de pathogenes, tel que le virus Ebola. Par la densification de sa presence et son extension spatiale generalisee, l’homme cree egalement de plus en plus de promiscuite avec les animaux sauvages. Dans l’espace CEDEAO, les chimpanzes et quelques especes de chauve-souris semblent representer le plus grand danger pour l’homme au regard du risque de transmission du virus Ebola. Cette etude replace l’epidemie d’Ebola survenue en 2013 en Guinee dans son contexte historique et panafricain. Puis, elle presente brievement le role connu de la faune sauvage dans l’epidemiologie d’Ebola et de quelles manieres les changements environnementaux operent sur les principaux reservoirs connus de ce virus. Ensuite, elle retrace les grandes lignes de l’evolution spatio-temporelle de l’epidemie d’Ebola survenue dans l’espace CEDEAO, en tentant de faire apparaitre les tenants et les aboutissants geographiques de cette catastrophe epidemiologique.

Este artigo busca resgatar as origens da geografia da saúde, desde a produção dos primeiros mapas de doenças até a incorporação de novas técnicas de análise espacial nas últimas décadas. Esta evolução também foi acompanhada por uma profunda revisão de paradigmas, teorias e métodos, ora com maior ênfase nas relações entre homem e ambiente, ora com abordagens que relacionam a estrutura socioespacial com os problemas de saúde nas diversas escalas em que estes se manifestam. A geografia da saúde atual se defronta com a necessidade de se articular a associação entre o processo de saúde-doença com o binômio doença-atenção, em busca da equidade, da prevenção de doenças e agravos e da promoção da saúde. Cet article cherche à retrouver les origines de la géographie de la santé, depuis la production des premières cartes des maladies jusqu'à l'incorporation de nouvelles techniques d'analyse spatiale au cours des dernières décennies. Cette évolution s'est également accompagnée d'une révision en profondeur des paradigmes, des théories et des méthodes, en mettant davantage l'accent sur la relation entre l'homme et l'environnement, et avec des approches qui relient la structure socio-spatiale aux problèmes de santé aux différentes échelles où ils se manifestent. La géographie actuelle de la santé est confrontée à la nécessité d'articuler l'association entre le processus santé-maladie et le binôme maladie-attention, à la recherche de l'équité, de la prévention des maladies et des maladies et de la promotion de la santé. This article seeks to recover the origins of health geography, from the production of the first disease maps to the incorporation of new spatial analysis techniques in the last decades. This evolution has also been accompanied by a profound review of paradigms, theories and methods, with a greater emphasis on the relationship between man and the environment, and with approaches that relate socio-spatial structure to health problems at the various scales where they manifest themselves. The current health geography is confronted with the need to articulate the association between the health-disease process and the disease-care binomial, in search of equity, prevention of diseases and diseases and health promotion.

This chapter examines the impact of climatic factors on health and disease in tropical zones. The tropics are the regions surrounding the Equator, delimited in latitude by the Tropic of Cancer in the Northern Hemisphere and the Tropic of Capricorn in the Southern Hemisphere. We examine the physical determinants that define the tropics and their direct and indirect roles in the maintenance of health and induction of disease. We discuss the influence of geographical features on ecosystems and living organisms, interactions that can promote the onset of disease (with cases studies) in different ecosystems, and anthropogenic changes and their impact on the ecosystem and, consequently, on human health. These physical constraints of the climate interfere largely with sociocultural and economical issues (see dedicated chapters), creating specific epidemiological conditions under the tropics.

Wesselsbron disease is a neglected mosquito transmitted Flavivirus infection that causes abortions and has teratogenic effects on sheep and cattle in Africa. Human can also be infected. The detection of human or animal cases is complicated by the non-specific symptoms close to Rift Valley Fever (RVF) in domestic livestock species or Dengue like syndrome in humans. Then, these detections are usually made during RVF investigations in sheep. These domestic animals should take a role in the life cycle of the virus but some evidences of Wesselsbron virus (WSLV) presence in wild animals suggest that the latter may be involved in the virus maintenance in nature. However, the reservoir status of wild vertebrate in general and rodents particularly for WSLV is only based on an isolation from a Cape short-eared gerbil in southern Africa. Most of WSLV isolations are from southern parts of Africa even if it has been found in western and central Africa or Madagascar. In Senegal, there are serological evidences of WSLV circulation in human since the 1970s and some isolations, the last one of which dates back in 1992. Despite the detection of the virus on mosquitoes until the 2000s in different parts of the country, no new human case has been noted. In this paper, we report the WSLV re-emergence in eastern Senegal in 2013 with 2 human cases and its first isolation from a black rat Rattus rattus. Sequencing analyses show the circulation of the same strain between these humans and the commensal rodent. The putative impact on WSLV transmission to human populations could be more important if the reservoir status of the black rat is confirmed. Focused survey in human populations, specific entomological and mammalogical investigations would permit a better understanding of the life cycle of the virus and its impact on public health., Highlights • Wesselsbron virus (WSLV) re-emerged in eastern Senegal in 2013 with 2 human cases and a black rat Rattus rattus. • Sequencing data showed circulation of the same strain among humans and black rat. • First reported isolation of WSLV from rodent since a Cape short-eared gerbil collected in 1968 in South Africa. • The potential impact on WSLV transmission to human could be more important should R. rattus be confirmed as reservoir. • Surveillance and field investigation on WSLV life cycle should be carried out to assess associated risk and impact of WSL on human health.

Mercury is known to be a powerful neurotoxin, particularly in its organic form. Amazonian populations living along contaminated rivers are exposed to mercurial contamination through fish consumption, but spatial disparities of contamination have very seldom been explored. The problem was addressed along the river Beni, in the Bolivian Amazon. Fifteen communities have been studied by a multidisciplinary research team, to explore the socio-geographical determinants of contamination by mercury. Using quantitative and qualitative methods, from the community to the regional level, this paper shows how spatial contrasts of mercury contamination are determined by contrasted types of resource management and contrasted social networks from one community to another, and how the places’ and societies’ specificities play an essential role in the determination of the mercurial risk.

Health geography in France has -for nearly a century now -contributed to the understanding of health inequalities in countries of the northern and southern hemispheres. Even though its conceptual structure and methodology were for the most part initially developed through the study of vector-borne diseases, health geography has subsequently extended its scope through focussing on emerging health issues. This presentation will demonstrate how a highly fruitful method, widely applied to the understanding of health inequalities of communicable diseases, has allowed us to engage in a novel health issue, barely explored by geographers so far : the study of the exposure in the long term to low level contamination by pollutants. With the example of mercury contamination disparities in the Bolivian Amazon region, this presentation confirms the efficiency of this method, which constitutes a starting point for the development of future research on the subject of environmental pollution., La géographie de la santé en France contribue depuis près d'un siècle à la compréhension des inégalités de santé dans les pays du Sud comme du Nord. Si son cadre conceptuel s'est forgé pour beaucoup grâce à l'étude des maladies transmissibles, elle s'est également largement renouvelée en se penchant sur les maux de son temps. Cette communication montre comment une démarche fructueuse largement appliquée à la compréhension des inégalités de santé liées aux maladies transmissibles a permis de revisiter et d'apporter un éclairage nouveau sur une thématique sanitaire encore peu explorée par les géographes : la contamination sur le long terme à de faibles doses de polluants. A travers l'étude des disparités de contamination par le mercure en Amazonie bolivienne, cette communication confirme l'efficacité de cette méthode, qui constitue une porte d'entrée pour le développement de futures recherches sur le thème des pollutions environnementales., Tschirhart Céline, Handschumacher Pascal, Laffly Dominique, Piermay Jean-Luc, Blanc Maurice, Luna Selma, Benefice Eric. Inégalités de contamination par le mercure le long du rio Béni (Bolivie) : un marqueur de l'inégale gestion et pratique des espaces par les communautés (Uneven mercury contamination alongside Rio Beni, Bolivia : a marker of uneven management and spatial practices by communities). In: Bulletin de l'Association de géographes français, 89e année, 2012-2. La géographie de la santé en France, sous la direction de Jeanne-Marie Amat-Roze. pp. 337-350.

Confrontee a un probleme d’assainissement, Rufisque a servi de cadre d’analyse des interactions entre insalubrite et sante a travers une focalisation sur la morbidite urbaine analysee avec des donnees epidemiologiques collectees aupres des menages et des centres de sante. La morbidite diarrheique tres elevee connait une variation spatio-temporelle. De plus, l’essentiel des pathologies diagnostiquees serait lie au deficit d’hygiene. Ainsi, ces tendances montrent que Rufisque souffre de son manque d’assainissement. Toutefois, les mobilisations citadines en faveur d’une meilleure qualite environnementale tendent a modifier cette structure du risque diarrheique.

La dengue, maladie transmise par un vecteur du genre aedes, est largement infeodee aux milieux urbains en raison des exigences ecologiques de son vecteur qui se reproduit dans les multiples collections d’eau generees par la ville et ses habitants. Cependant la diversite des paysages urbains semble entrainer des heterogeneites importantes de distribution de la maladie au sein meme de la ville. Si la diffusion de la maladie a l’echelle du globe s’appuie sur le developpement du fait urbain et notamment ses formes mal controlees, ainsi que sur l’acceleration des deplacements de populations, peut-on expliquer l’heterogeneite de la transmission en ville par les memes phenomenes mais dans leurs manifestations a grande echelle ? L’etude du cas de Santa Cruz de la Sierra, ville en pleine croissance d’un million et demi d’habitants, carrefour de circulation et « epicentre » de la maladie en Bolivie doit nous permettre de discuter de l’interaction entre les differents niveaux de determinants pour une meilleure prise en compte du risque sanitaire dans les politiques de developpement urbain. Une analyse critique de l’information et des resultats nous permet de mieux comprendre quelles inegalites sont revelees par la dengue pour une meilleure prise en charge de celles-ci.

International audience; In the contemporary context of zoonosis emergence and spread, invasive species are a major issue since they represent potential pathogen hosts. Even though many progresses have been done to understand and predict spatial patterns of invasive species, the challenge to identify the underlying determinants of their distribution remains a central question in invasion biology. This is particularly exacerbated in the case of commensal species that strictly depend on humankind for dispersal and perennial establishment of new populations. The distribution of these species is predicted to be influenced by dispersal opportunities and conditions acting on establishment and proliferation, such as environmental characteristics , including spatio-temporal components of the human societies. We propose to contribute to the understanding of the recent spread of a major invasive rodent species, the black rat (Rattus rattus), in the changing southeastern of Senegal. We address the factors that promote the dispersal and distribution of this invasive rodent from the perspective of human geography. We first describe characteristics of human settlements in terms of social and spatial organization of human societies (i.e. economic activities, commercial and agricultural networks, roads connectivity). We then explore the relationship between these characteristics and the distribution of this invasive rodent. Finally we propose that historical and contemporary dynamics of human societies have contributed to the risk of invasion of the black rat. We argue that the diffusion processes of invasive species cannot be considered as a result of the spatial structure only (i.e. connectivity and distance), but as a part of the human territory that includes the social and spatial organization. Results suggest that the distribution of invasive rodents partly results from the contemporary and inherited human socio-spatial systems, beyond the existence of suitable ecological conditions that are classically investigated by biologists.

Les techniques de modelisation basees sur le depla-cement d'agents dans une topologie de type graphe s'averent une approche fructueuse. Beaucoup de modeles lies aux deplacements d'agents utilisent l'algorithme de Dijkstra pour construire, a coup sur, les plus courts chemins. Cependant un probleme majeur de ces modeles est la frequence a laquelle les nombreux agents, durant toute la simulation, utilisent Dijkstra pour construire leurs plus courts chemins entre les positions ou ils se trou-vent et les positions ou ils veulent se rendre. Cette utilisation massive de l'algorithme necessite un grand temps de calcul. Dans cet article, nous proposons un algorithme permettant une optimisation spatiale de la representation informatique d'un graphe (matrice d'adjacence, liste d'adjacence), suivi d'un stockage optimise de tout plus court chemin une fois construit. Cette optimisation evite aux agents d'avoir a reconstruire des chemins deja construits et supprimes. Ce qui reduit considerablement le temps de calcul du a la construction de plus court chemins.

La contribution des etudes geographiques a la connaissance des grandes endemies tropicales a ete importante depuis la mise en place du programme de lutte contre l’onchocercose en 1975. Fortement articulees autour de collaborations avec biologistes et medecins, ces etudes ont permis de montrer l’importance de la gestion des espaces par les societes dans l’apparition, la diffusion et la propagation de ces grandes endemies. Par un jeu d’analyses a de multiples echelles tant spatiales que temporelles, cette approche a permis d’affiner un ensemble de concepts qui sont devenus autant d’outils indispensables a la comprehension du pouvoir epidemiogene des lieux. La multiplication des modeles dans des environnements differents a contribue a augmenter tant la connaissance des phenomenes que leur maitrise theorique. Cependant, malgre ces progres dans la connaissance bio-geographique des maladies et surtout ceux effectues dans le domaine de la therapie et de la lutte, la situation sanitaire ne s’est guere amelioree pour de nombreuses pathologies que l’on pensait pouvoir eradiquer avant la fin du xxe siecle. Les nombreuses avancees obtenues dans la mise au point des outils cartographiques et statistiques ainsi que ce constat d’echec relatif d’un point de vue operationnel nous obligent a resituer la priorite des enjeux sur les determinants princeps des politiques de sante et sur l’adequation entre connaissances sur la transmission et application en sante publique. La forte demande sociale contribue a donner une inflexion aux recherches geographiques, qui, en s’appuyant sur les nouveaux outils, s’inscrit deliberement dans une recherche appliquee a la sante publique.

Background Landscape may affect the distribution of infectious diseases by influencing the population density and dispersal of hosts and vectors. Plague (Yersinia pestis infection) is a highly virulent, re-emerging disease, the ecology of which has been scarcely studied in Africa. Human seroprevalence data for the major plague focus of Madagascar suggest that plague spreads heterogeneously across the landscape as a function of the relief. Plague is primarily a disease of rodents. We therefore investigated the relationship between disease distribution and the population genetic structure of the black rat, Rattus rattus, the main reservoir of plague in Madagascar. Methodology/Principal Findings We conducted a comparative study of plague seroprevalence and genetic structure (15 microsatellite markers) in rat populations from four geographic areas differing in topology, each covering about 150–200 km2 within the Madagascan plague focus. The seroprevalence levels in the rat populations mimicked those previously reported for humans. As expected, rat populations clearly displayed a more marked genetic structure with increasing relief. However, the relationship between seroprevalence data and genetic structure differs between areas, suggesting that plague distribution is not related everywhere to the effective dispersal of rats. Conclusions/Significance Genetic diversity estimates suggested that plague epizootics had only a weak impact on rat population sizes. In the highlands of Madagascar, plague dissemination cannot be accounted for solely by the effective dispersal of the reservoir. Human social activities may also be involved in spreading the disease in rat and human populations., Author Summary Plague (Yersinia pestis infection) is a highly virulent disease occurring in many natural ecosystems. One of the major plague foci is Madagascar, where plague has been confined principally to the central highlands since the 1920s. Despite the high prevalence of plague, its ecology has scarcely been studied. Previous studies of plague seroprevalence in humans have suggested that the disease spreads unevenly across landscapes, possibly due to the relief. Plague is primarily a disease of rodents. We therefore investigated the relationship between its distribution and the population genetic structure of its main reservoir, the black rat, Rattus rattus. We used serological and microsatellite-based population genetic analyses to compare four geographic areas of the plague focus (two mountainous areas, two plateaus). Rat populations had a more marked genetic structure in areas of greater relief. The heterogeneous distribution of plague in the highlands may be related to the population genetic structure of its reservoir, but our results suggest also a role for humans in the dispersion of the disease.

La dengue, maladie transmise par un vecteur du genre aedes, est largement inféodée aux milieux urbains en raison des exigences écologiques de son vecteur qui se reproduit dans les multiples collections d’eau générées par la ville et ses habitants. Cependant la diversité des paysages urbains semble entraîner des hétérogénéités importantes de distribution de la maladie au sein même de la ville. Si la diffusion de la maladie à l’échelle du globe s’appuie sur le développement du fait urbain et notamment ses formes mal contrôlées, ainsi que sur l’accélération des déplacements de populations, peut-on expliquer l’hétérogénéité de la transmission en ville par les mêmes phénomènes mais dans leurs manifestations à grande échelle ? L’étude du cas de Santa Cruz de la Sierra, ville en pleine croissance d’un million et demi d’habitants, carrefour de circulation et « épicentre » de la maladie en Bolivie doit nous permettre de discuter de l’interaction entre les différents niveaux de déterminants pour une meilleure prise en compte du risque sanitaire dans les politiques de développement urbain. Une analyse critique de l’information et des résultats nous permet de mieux comprendre quelles inégalités sont révélées par la dengue pour une meilleure prise en charge de celles-ci. Between Spaces at Risk and Mobilities : Appreciation of the Inequalities and Risk Management Dengue fever, transmitted by the aedes vector, is most prevalent in urban environments because of the ecological requirements of its vectors that reproduce in the multiple water collections generated by the city and its inhabitants. However the diversity of urban landscapes seems to determine the heterogeneous distribution of the disease across the urban landscape. Across the world, the diffusion of the disease is due in part to urban development, especially to uncontrolled development, and on the acceleration of population displacements. This study explores whether these large-scale processes are also at play at a more local scale, using the city of Santa Cruz de la Sierra, in Bolivia, as a case study. This city of a million and half of inhabitants is rapidly growing and is at the crossroads of circulation ; it is the epicentre of the disease in Bolivia. We examine the interaction between the various levels of risk factors influencing the disease and inequalities in its distribution. We discuss implications of the results for the development and implementation of urban policies, highlighting the importance of considering health hazards in their formulation.

Inherited from the work undertaken within the UR 024 "Epidemiology and prevention " and the UR 002 "Actors and health care systems in Africa ", health geography research of the UMR 912 SESSTIM is currently experiencing a renewal around the question of the diffusion and emergence of spaces at risk. Old and new works are articulated around the space homogeneities and discontinuities of the health risks revealing processes governing territories construction. The study of the health risk territorial dimension was focused around several models -plague in Madagascar, dengue in Bolivia, diarrhoeas of young children in Rufisque (Senegal), contamination by mercury of Amazonian populations (Bolivia) or seasonal variation of meningitis in Senegal -to understand the processes leading to a spatial variability of health risk. The goal of these studies was to identify determinants and space indicators of risk from a point of view of forecast and comprehension of the founding processes of health territories for a health directed planning. New studies started in early 2012 on the topics of anthropozoonosis diffusion in Senegal and Mali and the emergence of antimalarial resistances in Cambodia, thus leading to a renewal of the historical questionings of the team. Developed within an interdisciplinary framework and anchored academic formation curricula and research, both in " North " and "South " countries, this research has led to developing links between the universities of Strasbourg and more recently Marseilles in the North and Dakar, La Paz or Antananarivo in the South., Héritées des travaux menés au sein de l'UR 024 «Épidémiologie et prévention » et des travaux de l'UR 002 «Acteurs et systèmes de santé en Afrique », les recherches en géographie de la santé de l'UMR 912 SESSTIM connaissent actuellement un renouvellement autour de la question de la diffusion et de l 'émergence des espaces à risques sanitaires. Anciens et nouveaux travaux s 'articulent autour des homogénéités et discontinuités spatiales des risques sanitaires comme révélateurs des processus régissant la construction des territoires. L 'étude de la construction territoriale du risque sanitaire s 'est focalisée autour de plusieurs modèles-peste à Madagascar, dengue en Bolivie, diarrhées des jeunes enfants à Rufisque (Sénégal), contamination par le mercure de populations amazoniennes (Bolivie) ou saisonnalité de la méningite au Sénégal -pour comprendre les processus conduisant à la variabilité d'un risque sanitaire inscrit dans l'espace. Ces différents modèles avaient comme objectif d'identifier des déterminants et des indicateurs spatiaux de risque dans une optique de prévision et de compréhension des processus fondateurs des territoires de la santé pour un aménagement de l 'espace orienté santé. De nouveaux travaux voient le jour depuis début 2012 autour de la question de la diffusion des anthropozoonoses au Sénégal et au Mali et de l'émergence des résistances aux antipaludéens au Cambodge, conduisant ainsi à un renouvellement des problématiques historiques de l 'équipe Réalisées dans le cadre de l 'interdisciplinarité et ancrées dans des cursus de formation et de recherche universitaires tant au Nord qu 'au Sud, ces recherches ont conduit à développer des liens notamment avec l 'université de Strasbourg et récemment celle de Marseille pour le Nord et celles de Dakar, de La Paz ou d Antananarivo au Sud., Handschumacher Pascal. La géographie de la santé à l'UMR 912 SESSTIM (Health geography at UMR 912 SESSTIM). In: Bulletin de l'Association de géographes français, 89e année, 2012-2. La géographie de la santé en France, sous la direction de Jeanne-Marie Amat-Roze. pp. 327-336.

Many diseases were the object of geographical research within the team recently integrated within the UMR 912. We will focus here on two examples, the plague in Western Madagascar and dengue fever in the city of Santa Cruz of the Sierra (Bolivia), as emblematic of the type of research carried out. Supported by ANR funds, these two research projects sought to identify through the spatial heterogeneities of the diseases, the geographical roots leading to the variability of the risk. In that, these researches fit at the interface of environment and societies studies and allow us to understand how the construction, evolution and transformation of space will reveal the vulnerability of inherited spaces by the circulation of the disease-causing agent. These spaces will then be analysed in terms of planning and management process at multiple scales of time Whether it is the rural plague model or the urban dengue model, disease variability depends on the construction and transformation of spaces resulting from the human societies actions, making possible to identify the upstream disease determinants with a view of control and prevention., De nombreuses maladies ont fait l 'objet de travaux géographiques au sein de l'équipe désormais intégrée au sein de l'UMR 912. Nous retiendrons ici deux exemples, celui de la peste dans le Moyen-Ouest de Madagascar et celui de la dengue dans la ville de Santa Cruz de la Sierra (Bolivie) comme emblématiques des recherches effectuées. Soutenus par des financements ANR, ces deux projets de recherche ont cherché à identifier à travers l'expression spatiale différenciée de la maladie, les racines géographiques qui conditionnent la variabilité du risque. En cela, ils s'inscrivent dans une recherche à l 'interface des milieux et des sociétés pour comprendre comment la construction, l'évolution et la transformation des espaces va révéler par la circulation de l'agent pathogène la vulnérabilité d'espaces hérités de processus de gestion et d'aménagement à de multiples échelles de temps. Qu 'il s 'agisse du modèle de la peste rurale ou de la dengue urbaine, la variabilité de l'expression de ces pathologies dépend de la construction et de la transformation progressive ou rapide d'espaces comme produits des actions des sociétés humaines, permettant en cela d'identifier les déterminants en amont même de la maladie dans une optique de lutte et de prévention., Handschumacher Pascal. La variabilité des risques sanitaires comme indicatrice des processus de construction territoriale et des pratiques de l'espace : focus sur la peste et la dengue. (The variability of health risks as an indicator of territorial construction processes and spatial practices : a focus on plague and dengue). In: Bulletin de l'Association de géographes français, 89e année, 2012-2. La géographie de la santé en France, sous la direction de Jeanne-Marie Amat-Roze. pp. 351-361.

Human health is a field for specialists but also a universal concern. The increase in information and analysis in the various kinds of media make it possible for every one to form an opinion, right or wrong, on the health hazards that we will incur. In parallel, progress on experimental and investigative techniques, and dramatic increases in the masses of knowledge in the biological and medical disciplines has lead to an increasing splitting of research, to the detriment of the understanding on the overall pathogenic systems. This double situation very often leads to a division of simple relations between risk factors and medical impact, largely subdivided by disciplinary approaches The reality is that the emergence and/or the space-time variability of health hazards can be seldom expressed in simple relations of cause and effect. In France, during the period 1970–1980, H. Picheral, health geography Professor at the Montpellier University forged a new concept—the pathogenic system. For him, disease is the result of multiple interactions and reveals the physical and social structure of space (Picheral 1983). The initial object of research in health geography is thus the spatial, social and temporal variability of the disease and its factors—something that it has in common with epidemiology. But the final objective is to understand how the spatial heterogeneity of disease risk came into being, and how pathogenic systems function. Picheral distinguished four principal pathogenic systems

Potable water and sanitation facilities access constitutes one of the major problems faced by developing countries. In Senegal, more than 70% of urban centres lack drinking water distribution networks and satisfactory sewage systems. For this reason, public authorities have initiated series of institutional plans to strengthen the implementation of water and sanitation policies in various urban contexts as in the town of Rufisque. Geographical and epidemiological investigations were carried out from 2003 to 2005 to evaluate these policies impact in Rufisque. The goal was to assess health impact of various water supply and sewage management systems. Results show that operating different water supply and sewage management systems induces considerable variations on community’s sanitary, environmental, social, economic and political development. Despite of some progress made, many areas in the town still have difficulties to access to safe drinking water and to satisfactory sanitation services. The behaviours of the communities are still lacking the right changes. Spontaneous and growing urbanisation has increased the financial and other capacity shortfalls mainly at municipal levels. This paper makes an inventory of areas where these policies were implemented, and emphasizes the important role that scientific research would better have to play to reinforce their achievements.

International audience; We studied the epidemiology of cholera in Katanga and Eastern Kasai, in the Democratic Republic of Congo, by compiling a database including all cases recorded from 2000 through 2005. Results show that lakes were the sources of outbreaks and demonstrate the inadequacy of the strategy used to combat cholera.

International audience; BACKGROUND: Malaria is influenced by a web of individual and ecological factors, i.e. factors relating to people and relating to environment. For a long time analysing these factors concurrently has raised statistical problems. Multilevel modelling provides a new attractive solution, which is still uncommon in tropical medicine. METHODS: Using an actual data set of 3864 individuals from 38 villages of the Highland Madagascar, a two-level modelling process is presented. Individual malaria parasitaemia is modelled step by step according to age (individual factor), altitude, and DDT indoor house-spraying status (village factors). RESULTS: The hierarchical organization of a data set in levels, fixed and random effects, and cross-level interactions are considered. Accurate estimations of standard errors, impact of unknown or unmeasured variables quantified and accounted for through random effects, are the highlighted advantages of multilevel modelling. CONCLUSION: While not denying the importance of understanding an aetiological chain, the authors recommend an increased use of multilevel modelling, mainly to identify accurately ecological targets for public health policy.

The Re-emerging of Plague in Madagascar : a centennial Disease confronted to History and Ecology. Plague is a disease present in the world since the 5th century . But its story is still present because since 20 years, plague is growing in a majority of continents. In Madagascar we can now observe outbreaks in an urban area (the town of Majunga) while the central Highlands are confronted to endemic plague. A pluridisciplinary research group in Madagascar has focused his works on biological and medical approach but also on a geographical, historical and ecological one. Studying spatial and temporal modifications of the plague, authors try to show that the disease is illustrating heterogeneous landscapes leading to heterogeneous risk. These results must then lead to build health strategies up streams of the disease to prevent growing and spreading of plague in Madagascar., La peste est une maladie qui touche l'humanité depuis l'Antiquité. Mais son histoire n'appartient pas au passé car depuis maintenant une vingtaine d'années, cette maladie connaît un regain d'activité apparaissant sur presque tous les continents. Madagascar n'échappe pas à ce phénomène et connaît une peste qui se manifeste de façon épidémique dans un contexte urbain (la ville de Majunga) et circule de façon endémique sur les hautes terres rurales du centre et du nord de l'île. La présence dans la Grande île d'une équipe pluridisciplinaire et pluri-institutionnelle travaillant sur cette maladie a permis d'aborder la question non seulement sous l'angle biologique et médical mais également sous celui de l'histoire et de l'écologie humaine. En s 'appuyant sur les disparités spatiales et temporelles qui caractérisent la peste, les auteurs essayent de montrer que la peste est le reflet des déséquilibres engendrés par la gestion des milieux par les hommes dans un contexte présentant des prédispositions au risque pesteux. En s 'appuyant sur ces résultats, il devrait alors être possible de proposer des actions en amont de la maladie pour prévenir l'augmentation et la diffusion du risque., Handschumacher Pascal, Duplantier Jean-Marc, Chanteau Suzanne. La résurgence de la peste à Madagascar : une maladie centenaire à l'épreuve de l'histoire et de l'écologie. In: Espace, populations, sociétés, 2000-2. Maladies émergeantes et reviviscentes. pp. 195-208.