Stacy Emminger holds the death certificate for her son, Anthony, who was addicted to heroin. His death was marked as a multidrug toxicity in Pennsylvania. Ben Allen/WITF hide caption

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Secretary of State John Kerry and African Union Commission Chairperson Nkosazana Dlamini Zuma signed an agreement Monday to establish the first Centers for Disease Control and Prevention in Africa. The U.S. will provide technical advice and a few staff for the agency. Alex Wong/Getty Images hide caption

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Truvada can dramatically reduce the risk of HIV infection when taken as a preventative medicine — if taken every day. Studies are underway to determine if young people are likely to take the pill consistently. Justin Sullivan/Getty Images hide caption

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Stringy particles of Ebola virus (blue) bud from a chronically infected cell (yellow-green) in this colorized, scanning electron micrograph. NIAID/Science Source hide caption

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Dr. Thomas Frieden, director of the U.S. Centers for Disease Control and Prevention, talks with Doctors Without Borders staff during a visit in August to an Ebola treatment center in Monrovia, Liberia. Tommy Trenchard for NPR hide caption

itoggle caption Tommy Trenchard for NPR

Ebola patient Amber Vinson arrived by ambulance at Emory University Hospital on Oct. 15. Now healthy, Vinson was discharged from the hospital Tuesday. Kevin C. Cox/Getty Images hide caption

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