Wild boar (Sus scrofa) as a potential reservoir of infectious agents in Portugal: a review of two decades (2001–2021)

The wild boar (Sus scrofa) is a mammal with a broad distribution in the Eurasian territory and a potential reservoir for several zoonotic pathogens. Besides being part of the Mediterranean ecosystem and perpetuating these agents in the environment, this species is usually consumed in the Iberian Peninsula, representing a potential public health threat. Due to its extensive expansion and colonization of new geographical areas, which leads to increasing contact with humans, domestic animals, and wildlife, infectious disease assessments are crucial. During the last two decades (2001–2021), several researchers have studied wild boars to identify, understand, and predict potential health risks and disease outbreaks in animals and humans. North-eastern, central-eastern (mainly because of tuberculosis), and southern Portugal were the regions where most pathogens have been identified. Some agents with zoonotic importance (but with few reported data) should be the focus of future surveillance studies, such as Leptospira spp., Brucella spp., or Trichinella spp. This review aims to summarize the available information on pathogens (bacteria, viruses, and parasites) reported in wild boars, in Portugal, in the last two decades, with a particular focus on agents with zoonotic potential.