Une géographie des vulnérabilites territoriales face aux risques zoonotiques émergents

Dans cette contribution, je présente mes travaux de thèse qui portent sur les dynamiques d’invasion d’un hôte de zoonose dans un territoire en mutation, à travers l’exemple du rat noir au Sénégal Oriental. J’y expose la problématique et les objectifs de cette recherche, le cadre théorique et méthodologique, puis les grandes étapes de la démonstration. À travers ces trois parties, je m’attache à montrer l’originalité de ma recherche et son insertion parmi les innovations et la variété des appr..

Sociodemographic and Occupational Factors Associated with Low Early Uptake of COVID-19 Vaccine in Hospital-Based Healthcare Workers, Georgia, March–July 2021

In Georgia, an upper-middle income European country, the COVID-19 vaccine rollout began on 15 March 2021 with health workers (HWs), a priority group for vaccination. We assessed the factors associated with COVID-19 vaccination among HWs at six large hospitals in the early stages of the vaccine rollout (March–July 2021). Among 1533 HWs, 274 (17.9%) had received one dose of the COVID-19 vaccine. Strong independent predictors of early vaccine uptake were age > 40 years, especially 50–59 years old (aOR 2.40, 95% CI 1.50–3.88), considering the vaccine as “somewhat effective” or “very effective” rather than “not effective” (aOR 6.33, 95% CI 2.29–26.3 and aOR 10.9, 95% CI 3.88–45.70, respectively), and previous vaccination against seasonal influenza (aOR 2.98, 95% CI 2.19–4.08). Previous SARS-CoV-2 infection was negatively associated with receiving the vaccine (aOR 0.6, 95% CI 0.40–0.80). Compared to physicians, nurses/midwives (aOR 0.22, 95% CI 0.15–0.32), administrative staff (aOR 0.36, 95% CI 0.22–0.56), and ancillary staff (aOR 0.07, 95% CI 0.04–0.15) were less likely to have received the COVID-19 vaccine. Tailoring the COVID-19 vaccine communications campaign to younger and non-physician HWs, and emphasizing the benefits of the COVID-19 vaccine, could help further increase vaccine coverage among HWs in Georgia

Approche géographique du risque d'arboviroses liées aux rongeurs : le cas du rat noir au Sénégal oriental

Les anthropozoonoses s’imposent comme un enjeu de santé publique majeur. Maladies des animaux transmissibles à l’homme, ces dernières ont marqué l’Histoire, souvent par de grandes épidémies, depuis la peste antique aux récents épisodes de grippe aviaire. La question des anthropozoonoses se pose aujourd’hui de manière forte face aux modifications des aires de répartition de certaines espèces potentiellement réservoir d’agents infectieux et face à la mise en relation accrue des espaces. Cependant, l’espace du risque ne saurait être confondu avec la seule aire de présence d’une espèce-réservoir de pathogènes. En effet, depuis la présence d’espèces-réservoir jusqu’à la manifestation de différents niveaux de contamination chez l’homme, le risque d’anthropozoonoses dépend des modalités de contact dans l’espace entre les différents maillons de la chaîne épidémiologique. Il est alors possible d’appréhender les territoires du risque comme une construction issue des modes de gestion et des pratiques socio-spatiales des sociétés. Au Sénégal oriental l’arrivée récente du rat noir, rongeur commensal hôte potentiel de plusieurs virus, au gré des dynamiques territoriales anthropiques, soulève des interrogations sur le risque d’émergence anthropozoonoses dans cette région peu développée. Dans ce contexte, il s’agit notamment de s’interroger sur la vulnérabilité des territoires au regard de la diffusion et de la propagation du rongeur d’une part, et de sa mise en contact avec l’homme d’autre part

From Human Geography to Biological Invasions: The Black Rat Distribution in the Changing Southeastern of Senegal

International audienceIn 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

Description of clusters from the socio-spatial typologies per topic.

<p>Description of clusters from the socio-spatial typologies per topic.</p

Study area and survey sites.

<p><b>Clusters from the “synthetic socio-spatial” typology.</b> Study area and survey sites; black bold lines = national tarred roads; black thin lines = main untarred road; dashed grey lines = regional boundaries; the Dakar-Mali railway is strictly parallel to N1 road; Clusters from the "synthetic socio-spatial" typology (blue dots: rural localities with structuring capacities; red dots: marginal localities; green dots: urban-like localities; yellow dots: gold mining villages); Localities with socio-spatial data only: Gouniang, Dialacoto, Dienoundiala, Missira, Senoudebou.</p

Input categorical variables for MCA per topic.

<p>Input categorical variables for MCA per topic.</p

Seoul Orthohantavirus in Wild Black Rats, Senegal, 2012–2013

International audienceHantaviruses (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

Multilocus Genotyping of Giardia duodenalis in Mostly Asymptomatic Indigenous People from the Tapirapé Tribe, Brazilian Amazon.

Little information is available on the occurrence and genetic variability of the diarrhoea-causing enteric protozoan parasite Giardia duodenalis in indigenous communities in Brazil. This cross-sectional epidemiological survey describes the frequency, genotypes, and risk associations for this pathogen in Tapirapé people (Brazilian Amazon) at four sampling campaigns during 2008-2009. Microscopy was used as a screening test, and molecular (PCR and Sanger sequencing) assays targeting the small subunit ribosomal RNA, the glutamate dehydrogenase, the beta-giardin, and the triosephosphate isomerase genes as confirmatory/genotyping methods. Associations between G. duodenalis and sociodemographic and clinical variables were investigated using Chi-squared test and univariable/multivariable logistic regression models. Overall, 574 individuals belonging to six tribes participated in the study, with G. duodenalis prevalence rates varying from 13.5-21.7%. The infection was positively linked to younger age and tribe. Infected children <15 years old reported more frequent gastrointestinal symptoms compared to adults. Assemblage B accounted for three out of four G. duodenalis infections and showed a high genetic diversity. No association between assemblage and age or occurrence of diarrhoea was demonstrated. These data indicate that the most likely source of infection was anthropic and that different pathways (e.g., drinking water) may be involved in the transmission of the parasite.This research was funded by the São Paulo State Research Support Foundation (FAFESP, Brazil), the National Health Foundation (FUNASA, Brazil), and the Mato Grosso State Research Support Foundation (FAPEMAT, Brazil), grant number 0839/2006. Additional funding was obtained from the Health Institute Carlos III (ISCIII), Ministry of Economy and Competitiveness (Spain), grant number PI16CIII/00024.S