An ongoing outbreak of Ebola Virus Disease (EVD), the largest, most persistent ever documented, and the first in West Africa, began in March 2014 in Guinea, Sierra Leone, and Liberia (the “affected countries”) and has spread to Nigeria. More people have contracted and died from EVD in this outbreak than in any single prior outbreak. In the current outbreak, the case fatality rate (the estimated percentage of infected persons dying) is about 55%; past outbreak rates have ranged between 41% and 88%.Source: US Congressional Research Service, Library of Congress
Prior human EVD outbreaks had occurred in the Democratic Republic of Congo, Gabon, Sudan, and Uganda, primarily in rural and forested areas (Figure 2). The current outbreak is more geographically extensive and cases are emerging in both urban and rural settings. Health experts are accelerating efforts to contain the outbreak, as transmission in densely populated urban areas may be far more difficult to control and lead to higher death tolls. According to the World Health Organization (WHO), from March through August 6, Ebola was known or suspected to have infected 1,779 persons and caused 961 deaths; of these, 1,134 cases had been confirmed in laboratories.
Download pdf: Ebola: 2014 Outbreak in West Africa – CRS Report