Spillover effect

Context (archaeology)

Biology

Microeconomics

Virology

Telecommunications

Economics

Computer science

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)

Environmental health

Coronavirus disease 2019 (COVID-19)

Paleontology

Infectious disease (medical specialty)

Medicine

Transmission (telecommunications)

Pandemic

Zoonosis

Disease

Pathology

Genetics and Molecular Biology

The transmission of pathogens from wild animals to humans is called “zoonotic spillover”. Most human infectious diseases (60-75%) are derived from pathogens that originally circulated in non-human animal species. This demonstrates that spillover has a fundamental role in the emergence of new human infectious diseases. Understanding the factors that facilitate the transmission of pathogens from wild animals to humans is essential to establish strategies focused on the reduction of the frequency of spillover events. In this context, this article describes the basic aspects of zoonotic spillover and the main factors involved in spillover events, considering the role of the inter-species interactions, phylogenetic distance between host species, environmental drivers, and specific characteristics of the pathogens, animals, and humans. As an example, the factors involved in the emergence of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic are discussed, indicating what can be learned from this public health emergency, and what can be applied to the Brazilian scenario. Finally, this article discusses actions to prevent or reduce the frequency of zoonotic spillover events.

Zoonotic spillover: Understanding basic aspects for better prevention