Fragmentation of the territory and the risk of zoonosis

A zoonosis is any infectious disease transmitted naturally from animals to humans. Some of these diseases are those caused by Ebola, West Nile virus, SARS-CoV, Marburg virus and many others (Zohdy et al., 2019). El COVID-19 it is also a zoonosis.

The risk of zoonosis increases in areas where humans and animals interact, with direct or indirect exposure.

There are several studies that link habitat fragmentation and biodiversity loss to the risk of the emergence of new infectious diseases.

A paper by Wilkinson and collaborators (2018) presents a theoretical framework that takes advantage of the species-area relationship to relate population exposure to new infectious diseases with habitat biodiversity.

In this study, they model changes in exposure to pathogens related to different levels of habitat fragmentation, trying to predict that increasing habitat division increases the risk of pathogens for biological systems. They conclude that by studying landscape ecology, high-risk areas can be identified to carry out mitigation measures focused on biodiversity conservation).

Referring to the first post we published related to landscape connectivity, it should be noted that habitat fragmentation is the cause of the increase in the edge effect, which increases the interface at which human beings can contact these disease-causing microorganisms or viruses.

A case study that serves as an example is the Ebola outbreak in Guinea in early 2014. Zorello Porta (2014) indicates that in a fragmented landscape of 100 km2 in which 50-60% of the territory was anthropized, the increase in the edge effect was between 10 and 12 times greater than in a landscape without such fragmentation, being one of the causes of contact between humans and the harmful pathogen. In 2017, Rulli and collaborators observed, after carrying out a study of the structure of the landscape, that the majority of Ebola outbreaks occurred in hot spots of forest fragmentation.

Therefore, it is worth highlighting the key role of the analysis of ecological connectivity and the fragmentation of ecosystems in landscape management, promoting the conservation of biodiversity.

BIBLIOGRAPHY

• Environmental ideas. 2019. The importance of ecological connectivity or landscape connectivity
• Rulli MC, Santini M, Hayman DTS, D'Odorico P. 2017. The nexus between forest fragmentation in Africa and Ebola virus disease outbreaks. Skiing. Rep. 7, 41613; doi: 10.1038/srep41613
• Wilkinson DA, Marshall JC, French NP, Hayman DTS. 2018. Habitat fragmentation, biodiversity loss and the risk of novel infectious disease emergence. JR Soc Interface 15 (149)
• Zodhy S, Schwartz TS, Oaks JR. 2019. The coevolution effect as a driver of spillover. Trends in parasitology. Vol 35 (6), 399-408. (DOI: 10.1016/j.pt.2019.03.010)
• Zorello Porta, G. 2014. Landscape fragmentation and Ebola outbreaks. Mem Inst Oswaldo, Rio de Janeiro, Vol 109 (8): 1088-1088.