In August 2014, Dr. Thomas Frieden, director of the U.S. Centers for Disease Control and Prevention, talked with Doctors Without Borders staff during a visit to an Ebola treatment center in Monrovia, Liberia.
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A patient suffering from Guillain-Barre syndrome recovers in a hospital ward in San Salvador on Jan. 27. Researchers are trying to determine whether there is a link between the disorder, which can cause weakness and paralysis, and the mosquito-borne Zika virus.
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A security fence surrounds the main part of the U.S. Army's Dugway Proving Ground, a testing laboratory in the Utah desert. The Army says it mistakenly shipped live anthrax from Dugway to several labs in the U.S. and Korea.
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