The current outbreak of Ebola virus disease (EVD) in West Africa is unlike any of the previous outbreaks caused by the disease because of the unprecedented speed with which it is evolving. A number of countries in western Africa are currently affected – Guinea, Liberia, Sierra Leone and Democratic Republic of Congo. All these countries have now reported laboratory-confirmed cases. The outbreak, which probably began as an event of acute febrile illness associated with a high case fatality rate, was first identified in December 2013 in the Guéckédou region of Guinea–Conakry, a remote region of southeast Guinea bordering Sierra Leone and Liberia (1). It soon escalated with rapidly increasing numbers of cases reported from these three countries, possibly due to constant movement of people across their porous borders, raising a high public health alert across the continent. The World Health Organization was officially notified of an outbreak of EVD on 23 March 2014 (2).