An Ebola virus epidemic in Sierra Leone occurred in 2014, along with the neighbouring countries of Guinea and Liberia. At the time it was discovered, it was thought that Ebola virus was not endemic to Sierra Leone or to the West African region and that the epidemic represented the first time the virus was discovered there.[2] However, US researchers pointed to lab samples used for Lassa fever testing to suggest that Ebola had been in Sierra Leone as early as 2006.[3]