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.

中文翻译：

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人畜共患病溢出：了解更好预防的基本方面。

病原体从野生动物向人类传播被称为“人畜共患外溢”。大多数人类传染病（60-75%）源自最初在非人类动物物种中传播的病原体。这表明外溢在新的人类传染病的出现中具有根本性的作用。了解促进病原体从野生动物向人类传播的因素对于制定专注于减少溢出事件频率的战略至关重要。在此背景下，本文描述了人畜共患病溢出的基本方面和溢出事件涉及的主要因素，考虑了物种间相互作用的作用、宿主物种之间的系统发育距离、环境驱动因素以及病原体、动物、和人类。例如，讨论了严重急性呼吸系统综合症冠状病毒 2 (SARS-CoV-2) 大流行的出现所涉及的因素，指出可以从这次突发公共卫生事件中学到什么，以及可以应用于巴西的情况。最后，本文讨论了预防或减少人畜共患病溢出事件频率的行动。