Zootherapy and zoonotic risk: a global evaluation of the relationship between the use of body parts in traditional medicine and the risk of pathogen exposure.

Traditional medicinal practices involve recurrent contact between humans and animal body parts, increasing the chance of zoonotic transmission. However, the factors associated with zoonotic risk in mammal species utilized as medicine are still poorly understood. Here, we investigate global patterns of zoonotic potential in medicinal mammals, evaluating the effects of risks associated with tissue type, phylogenetic closeness, gregarious behavior, body mass and therapeutic versatility. We modeled the species' zoonotic potential by adjusting generalized linear models with mixed effects. The best supported model included a composite risk score that integrates the risk associated to biological tissue, phylogenetic proximity and gregarious behavior. Zoonotic potential was positively associated with the type of tissue used and body mass, while therapeutic versatility did not present a significant independent effect. The risk associated with body tissue varied among mammal orders, with the highest-risk tissues predominating in Didelphimorphia, Lagomorpha and Perissodactyla, Cetacea, Chiroptera, Carnivora and Rodentia. Our results indicate that zoonotic risk in medicinal mammals is more strongly associated with biological and ecological characteristics of the species than to the diversity of medicinal applications per species alone. Biologically active tissues, especially in gregarious species phylogenetically closer to humans, can increase the odds or exposure to and transmission of zoonotic pathogens. Popular medicinal practices involving the consumption of mammals and their byproducts represent an important interface for zoonotic spillover. There is an urgent need to incorporate and observe zootherapeutic practices in epidemiological surveillance through a One Health approach to mitigate the risks associated with the practice.