Abstract:
Zoonotic spillover is a phenomenon characterized by the transfer of pathogens
between different animal species. Most human emerging infectious diseases originate
from non-human animals, and human-related environmental disturbances are the
driving forces of the emergence of new human pathogens. Synthesizing the sequence
of basic events involved in the emergence of new human pathogens is important for
guiding the understanding, identifi cation, and description of key aspects of human
activities that can be changed to prevent new outbreaks, epidemics, and pandemics.
This review synthesizes the connections between environmental disturbances and
increased risk of spillover events based on the One Health perspective. Anthropogenic
disturbances in the environment (e.g., deforestation, habitat fragmentation, biodiversity
loss, wildlife exploitation) lead to changes in ecological niches, reduction of the dilution
effect, increased contact between humans and other animals, changes in the incidence
and load of pathogens in animal populations, and alterations in the abiotic factors of
landscapes. These phenomena can increase the risk of spillover events and, potentially,
facilitate new infectious disease outbreaks. Using Brazil as a study model, this review
brings a discussion concerning anthropogenic activities in the Amazon region and their
potential impacts on spillover risk and spread of emerging diseases in this region.
