Deforestation and Spillover of Zoonotic Viruses in South America: Evidence and Knowledge Gaps

Most emerging human infectious diseases are of zoonotic origin and caused by viruses prone to epidemic events. Zoonosis is becoming more frequent and intense, driven primarily by major environmental changes such as deforestation. Two of the most threatened tropical forests in South America are the Amazon Forest and the Atlantic Forest. How forest degradation has facilitated the zoonotic spread of new emerging or reemerging viruses in these forests is a matter of concern. Thus, the main objective of this work was to review the existing evidence on the impact of deforestation on the emergence of zoonotic viruses in South America. Few studies were found and they were restricted to the emergence/reemergence of hantavirus, yellow fever virus (YFV), and rabies virus in the highly fragmented forests of Brazil. Most evidence suggests a protective role of host/vector diversity in less degraded forests in terms of viral zoonotic risk. Gaps in the knowledge are identified paving the way for future research in the region. Managing emerging viral zoonoses will require an integrated understanding of how the cascading impacts of forest conversion affect disease outcomes following a multidisciplinary One Health approach.