Volunteers transporting vital goods on boats in Liberia.
A few people are seen during a three-day lockdown to prevent the spread of the Ebola virus, in Freetown, Sierra Leone, Sunday, Sept. 21, 2014. Volunteers going door to door during a three-day lockdown intended to combat Ebola in Sierra Leone say some residents are growing increasingly frustrated and complaining about food shortages. Michael Duff / AP photo
A hygienist in Guinea approaches patients who are awaiting the results of blood tests that will disclose their Ebola status. Sylvain Cherkaoui / Cosmos
A nurse attends a new arrival in Sierra Leone.
Disinfecting workers in Liberia. Martin Zinggl / MSF
A colorized transmission electron micrograph (TEM) of an Ebola virus virion. Cynthia Goldsmith / EPA