A plan for community event-based surveillance to reduce Ebola transmission - Sierra Leone, 2014-2015.

Ebola virus disease (Ebola) was first detected in Sierra Leone in May 2014 and was likely introduced into the eastern part of the country from Guinea. The disease spread westward, eventually affecting Freetown, Sierra Leone's densely populated capital. By December 2014, Sierra Leone had more Ebola cases than Guinea and Liberia, the other two West African countries that have experienced widespread transmission.