Lassa fever is one of the pathogens in the WHO R&D Blueprint list of epidemic threats needing urgent R&D action. It is a zoonotic disease associated with acute and potentially fatal haemorrhagic illness caused by Lassa virus (LASV). Lassa fever was first described and LASV was first isolated in 1969 when two missionary nurses became ill and died in the town of Lassa, Nigeria. Since then, Lassa fever has been shown to be prevalent in many West African countries, such as Benin, Ghana, Guinea, Liberia, Mali, Nigeria, and Sierra Leone. In these countries, both sporadic cases and prolonged outbreaks of the disease are observed. Lassa virus is transmitted to humans via contact with food or household items contaminated with rodent urine or faeces. Person-to-person infections and laboratory transmission can also occur, particularly in hospitals lacking adequate infection prevention and control measures.