Emerging Mammarenaviruses in Wildlife: Expanding Host Range and Implications

Mammarenaviruses are enveloped, ambisense, single-stranded RNA viruses capable of causing fatal hemorrhagic fevers and severe neurological disorders in humans. Although muroid rodents have historically been recognized as the primary reservoirs for major pathogens like Lassa virus, recent surveillance has revealed a significant expansion of their host range. This review aims to synthesize current global data regarding the epidemiology of mammarenaviruses in conventional reservoirs and the emergence of novel arenaviruses in non-traditional mammalian hosts. To achieve this, we comprehensively analyzed recent molecular and metagenomic surveillance data, evolutionary studies, and epidemiological reports published worldwide. Key discoveries include Wenzhou virus in Asian house shrews, Plateau Pika virus in plateau pikas, and an independent, geographically clustered of hedgehog-associated arenaviruses across Europe. Ultimately, this review underscores the global distribution of these pathogens and the critical need for continued, multi-host surveillance worldwide.