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Pathogenic landscapes: interactions between land, people, disease vectors, and their animal hosts.

Lambin EF, Tran A, Vanwambeke SO, Linard C, Soti V - Int J Health Geogr (2010)

Bottom Line: We formulated ten propositions that are related to landscape attributes, spatial patterns and habitat connectivity, pathways of pathogen transmission between vectors and hosts, scale issues, land use and ownership, and human behaviour associated with transmission cycles.We also highlight the complementarity of the modelling approaches used in our case studies.Integrated analyses at the landscape scale allows a better understanding of interactions between changes in ecosystems and climate, land use and human behaviour, and the ecology of vectors and animal hosts of infectious agents.

View Article: PubMed Central - HTML - PubMed

Affiliation: Georges LemaƮtre Centre for Earth and Climate Research, Earth and Life Institute, University of Louvain, 3 place Pasteur, Louvain-la-Neuve, B-1348, Belgium. eric.lambin@uclouvain.be

ABSTRACT

Background: Landscape attributes influence spatial variations in disease risk or incidence. We present a review of the key findings from eight case studies that we conducted in Europe and West Africa on the impact of land changes on emerging or re-emerging vector-borne diseases and/or zoonoses. The case studies concern West Nile virus transmission in Senegal, tick-borne encephalitis incidence in Latvia, sandfly abundance in the French Pyrenees, Rift Valley Fever in the Ferlo (Senegal), West Nile Fever and the risk of malaria re-emergence in the Camargue, and rodent-borne Puumala hantavirus and Lyme borreliosis in Belgium.

Results: We identified general principles governing landscape epidemiology in these diverse disease systems and geographic regions. We formulated ten propositions that are related to landscape attributes, spatial patterns and habitat connectivity, pathways of pathogen transmission between vectors and hosts, scale issues, land use and ownership, and human behaviour associated with transmission cycles.

Conclusions: A static view of the "pathogenecity" of landscapes overlays maps of the spatial distribution of vectors and their habitats, animal hosts carrying specific pathogens and their habitat, and susceptible human hosts and their land use. A more dynamic view emphasizing the spatial and temporal interactions between these agents at multiple scales is more appropriate. We also highlight the complementarity of the modelling approaches used in our case studies. Integrated analyses at the landscape scale allows a better understanding of interactions between changes in ecosystems and climate, land use and human behaviour, and the ecology of vectors and animal hosts of infectious agents.

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Graphical representation of the landscape determinants of disease transmission. The numbers refer to the ten propositions formulated in this paper.
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Figure 2: Graphical representation of the landscape determinants of disease transmission. The numbers refer to the ten propositions formulated in this paper.

Mentions: This general proposition applies to all our studies (Table 2). The distribution, density, behaviour, and population dynamics of arthropod vectors and their non-human hosts are partially controlled by landscape features. The spatial distribution of vectors and the level of transmission is thus influenced by the environment [28,29]. This was illustrated by studies testing the relationship between disease occurrence and environmental features [30,31]. The case of WNV in Senegal illustrates this link, and the subsequent propositions provide details on the causal links between landscapes and diseases (Figure 2). In the serological study in the Senegal River basin, Chevalier et al. [20] found that IgG seroprevalence rate in horses was decreasing with proximity to seawater, flooded banks and salted mudflats. These landscape features acted as protective factors as they are highly unfavourable to the presence of Culex mosquitoes, the main WNV vectors. In Senegal, environmental constraints on vector distribution are more limitative for WNV transmission than bird distribution. Similar results were observed in the Camargue region, France and in Iowa, also with significant relationships between landscape features and seroprevalence of WNV [32,33], with different risk and protective factors though. This highlights the need for a landscape scale analysis of infections, especially when there are multiple possible hosts and vectors species.


Pathogenic landscapes: interactions between land, people, disease vectors, and their animal hosts.

Lambin EF, Tran A, Vanwambeke SO, Linard C, Soti V - Int J Health Geogr (2010)

Graphical representation of the landscape determinants of disease transmission. The numbers refer to the ten propositions formulated in this paper.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2984574&req=5

Figure 2: Graphical representation of the landscape determinants of disease transmission. The numbers refer to the ten propositions formulated in this paper.
Mentions: This general proposition applies to all our studies (Table 2). The distribution, density, behaviour, and population dynamics of arthropod vectors and their non-human hosts are partially controlled by landscape features. The spatial distribution of vectors and the level of transmission is thus influenced by the environment [28,29]. This was illustrated by studies testing the relationship between disease occurrence and environmental features [30,31]. The case of WNV in Senegal illustrates this link, and the subsequent propositions provide details on the causal links between landscapes and diseases (Figure 2). In the serological study in the Senegal River basin, Chevalier et al. [20] found that IgG seroprevalence rate in horses was decreasing with proximity to seawater, flooded banks and salted mudflats. These landscape features acted as protective factors as they are highly unfavourable to the presence of Culex mosquitoes, the main WNV vectors. In Senegal, environmental constraints on vector distribution are more limitative for WNV transmission than bird distribution. Similar results were observed in the Camargue region, France and in Iowa, also with significant relationships between landscape features and seroprevalence of WNV [32,33], with different risk and protective factors though. This highlights the need for a landscape scale analysis of infections, especially when there are multiple possible hosts and vectors species.

Bottom Line: We formulated ten propositions that are related to landscape attributes, spatial patterns and habitat connectivity, pathways of pathogen transmission between vectors and hosts, scale issues, land use and ownership, and human behaviour associated with transmission cycles.We also highlight the complementarity of the modelling approaches used in our case studies.Integrated analyses at the landscape scale allows a better understanding of interactions between changes in ecosystems and climate, land use and human behaviour, and the ecology of vectors and animal hosts of infectious agents.

View Article: PubMed Central - HTML - PubMed

Affiliation: Georges LemaƮtre Centre for Earth and Climate Research, Earth and Life Institute, University of Louvain, 3 place Pasteur, Louvain-la-Neuve, B-1348, Belgium. eric.lambin@uclouvain.be

ABSTRACT

Background: Landscape attributes influence spatial variations in disease risk or incidence. We present a review of the key findings from eight case studies that we conducted in Europe and West Africa on the impact of land changes on emerging or re-emerging vector-borne diseases and/or zoonoses. The case studies concern West Nile virus transmission in Senegal, tick-borne encephalitis incidence in Latvia, sandfly abundance in the French Pyrenees, Rift Valley Fever in the Ferlo (Senegal), West Nile Fever and the risk of malaria re-emergence in the Camargue, and rodent-borne Puumala hantavirus and Lyme borreliosis in Belgium.

Results: We identified general principles governing landscape epidemiology in these diverse disease systems and geographic regions. We formulated ten propositions that are related to landscape attributes, spatial patterns and habitat connectivity, pathways of pathogen transmission between vectors and hosts, scale issues, land use and ownership, and human behaviour associated with transmission cycles.

Conclusions: A static view of the "pathogenecity" of landscapes overlays maps of the spatial distribution of vectors and their habitats, animal hosts carrying specific pathogens and their habitat, and susceptible human hosts and their land use. A more dynamic view emphasizing the spatial and temporal interactions between these agents at multiple scales is more appropriate. We also highlight the complementarity of the modelling approaches used in our case studies. Integrated analyses at the landscape scale allows a better understanding of interactions between changes in ecosystems and climate, land use and human behaviour, and the ecology of vectors and animal hosts of infectious agents.

Show MeSH
Related in: MedlinePlus