Miguel Pajares, a Spanish priest who was infected with the Ebola virus while working in Liberia, is transferred from a plane to an ambulance after arriving in Spain. He was treated with an experimental drug but died on the disease. Spanish Defense Ministry/AP hide caption

itoggle caption Spanish Defense Ministry/AP

In 1995, amid an Ebola outbreak, Zairian Red Cross personnel picked up sick people and bodies left on the streets of Kikwit, 250 miles from the capital Kinshasa. Jean-Marc Bouju/AP hide caption

itoggle caption Jean-Marc Bouju/AP

AIDS drugs line a pharmacy's shelves. A new recommendation from the World Health Organization suggests a daily anti-HIV pill for men who have sex with men. Astrid Riecken/MCT/Landov hide caption

itoggle caption Astrid Riecken/MCT/Landov

A nurse walks towards the Roger Salengro Hospital in Lille, France, where two patients were diagnosed with a coronavirus related to SARS. Michel Spingler/AP hide caption

itoggle caption Michel Spingler/AP

A health worker injects a woman with a shot of Depo Provera, a quarterly contraceptive injection, at a health clinic in Busia, Uganda, in 2009. MCT/MCT via Getty Images hide caption

itoggle caption MCT/MCT via Getty Images