Genomic changes of Lassa virus associated with mammalian host adaptation

Lassa virus (LASV) causes a severe haemorrhagic fever with approximately 100,000 to 500,000 cases annually in endemic regions and accounting for around 5000 deaths. The natural reservoir is the Mastomys rat, but through zoonotic transmissions humans are accidental hosts. Regular outbreaks continue to exert pressures on public health systems, with its ability to cause nosocomial infections posing risks to healthcare workers. It is a concern that larger outbreaks and introduction of LASV to new territories will intensify, including risk of adaptation to new mammalian host reservoirs.