Faculté des Sciences
Faculté des Sciences

The effects of landscape changes on the Brazilian spotted fever incidence in the Atlantic Forest over the last two decades.

Conserva, Nicolas ULiège
Promotor(s) : Vanderpoorten, Alain ULiège ; Tombasi, Léandro
Date of defense : 26-Jan-2024 • Permalink :
Title : The effects of landscape changes on the Brazilian spotted fever incidence in the Atlantic Forest over the last two decades.
Translated title : [fr] Les effets des modifications du paysage sur l'incidence de la fièvre pourprée des montagnes rocheuses dans la Forêt Atlantique durant les deux dernières décennies
Author : Conserva, Nicolas ULiège
Date of defense  : 26-Jan-2024
Advisor(s) : Vanderpoorten, Alain ULiège
Tombasi, Léandro 
Committee's member(s) : Linden, Annick ULiège
Dellicour, Simon 
Language : English
Number of pages : 82
Keywords : [fr] Environmental epidemiology
[fr] Zoonoses
[fr] Spotted fever
[fr] Atlantic Forest
[fr] Landscape changes
[fr] vector-born disease
[fr] environment health
Discipline(s) : Life sciences > Environmental sciences & ecology
Research unit : University Federal of ABC - Environmental and Urban Systems Integration Laboratory
Target public : Researchers
General public
Institution(s) : Université de Liège, Liège, Belgique
Degree: Master en biologie des organismes et écologie, à finalité approfondie
Faculty: Master thesis of the Faculté des Sciences


[fr] Zoonoses have become an increasing area of concern since the last decades. Landscape changes increase the spatial overlap between reservoir hosts and human habitats, thereby raising the risk of effective spillover. It is crucial to monitor the emergence patterns of zoonoses to reduce their incidence, which can be done in light of environmental epidemiology. The Brazilian spotted fever (BSF) is a vector-born disease transmitted by ticks of the Amblyomma genus and whose etiological agents are Rickettsia bacteria. Despite low incidence of the disease, it has a high annual lethality rate. Moreover, the BSF sylvatic cycle involves amplifier hosts that can raise up pathogen prevalence in the environment. The Atlantic Forest is a tropical biome that has undergone several landscape changes, especially deforestation for pasture and agriculture expansion, and is known to contain most of the BSF incidence. Hence, this thesis aims at characterizing the effects of landscape changes on the BSF incidence, and in particular, at assessing which landscape features promote high incidence levels. Several hypotheses based on the host ecology were tested using different variables of landscape structure and configuration. Epidemiologic data of BSF by municipality were downloaded. Data on land use and land cover were retrieved from the MapBiomas initiative. Additional data on municipalities, hydrography, elevation, and climate were gathered. For each municipality, landscape structure and additional data were processed using geographic information systems. Landscape configuration metrics were calculated using the FRAGSTATS software. Subsequently, the relationships between BSF incidence and landscape features were assessed using generalized linear mixed models in RStudio. First, general explanatory model using environmental principal component analysis was carried out. Second, competing hypotheses regarding the role of specific environmental features were tested using multiple Akaike information criterion model selection. The results shows that BSF cases have increased over the last two decades and most of them were located in the Atlantic Forest. There was a significant correlation between BSF incidence and forest cover, especially riparian forests cover immersed in pasture and agriculture landscape matrices. The results are interpreted by the ecological requirements of BSF tick vectors and their hosts in the context of landscape changes in the Atlantic Forest over the period studied. Finally, applications for an enhanced preventive framework of the disease are discussed.



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  • Conserva, Nicolas ULiège Université de Liège > Master biol. orga. & écol., fin. approf.


Committee's member(s)

  • Linden, Annick ULiège Université de Liège - ULiège > Département des maladies infectieuses et parasitaires (DMI) > Santé et pathologies de la faune sauvage
    ORBi View his publications on ORBi
  • Dellicour, Simon Université libre de Bruxelles > Spatial Epidemiology Lab
  • Total number of views 40
  • Total number of downloads 34

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