Barbara Bush helps a nun to fit on a hearing device during a 2012 event in Gulu, Uganda. She says was interested in architecture as a college student but became a global health activist after visiting East Africa with her parents. Reuters/Landov hide caption
A technician tests samples from Ebola-infected patients at a field lab, run by Doctors Without Borders, in Kailahun, Sierra Leone. Tommy Trenchard for NPR hide caption
A scientist tests a patient's blood for Ebola at the European Mobile Laboratory in Gueckedou, Guinea. The first cases reported in the outbreak occurred in a small village about eight miles outside Gueckedou. Misha Hussain/Reuters /Landov hide caption
Jude Law prepares for the looming pandemic in the 2011 movie Contagion. There are huge differences between viruses in movies and Ebola in real life. Warner Bros/The Kobal Collection hide caption
The ancient people of Peru have a spiritual connection to sea lions (shown here at Peru's Paracas national park). They may have had a bacterial connection as well. iStockphoto hide caption
Workers with the aid group Doctors Without Borders prepare a new Ebola treatment center near Monrovia, Liberia, on Sunday. The facility has 120 beds, making it the largest Ebola isolation clinic in history. John Moore/Getty Images hide caption
Marqui Ducarme is aided by his wife after catching chikungunya at his home in Port-au-Prince, May 23. The virus swept through Haiti this spring, infecting more than 40,000 people. Marie Arago/Reuters/Landov hide caption
A man lies in a newly opened Ebola isolation center in a closed school in Monrovia, Liberia, on Thursday. The official death toll of 1,000 people in four countries is likely below the actual number, the World Health Organization says. John Moore/Getty Images hide caption
Better than Egyptian cotton: This electrically spun fabric contains anti-HIV drugs and dissolves rapidly when it gets wet. Courtesy of University of Washington hide caption
An outbreak of bird flu in India in 2008 prompted authorities to temporarily ban the sale of poultry. Diptendu Dutta/AFP/Getty Images hide caption
How do you prevent the spread of Ebola? Wash your hands, avoid bush meat and don't touch corpses. Ofeibea Quist-Arcton/NPR hide caption
A woman washes her hands before she is allowed to enter a building — part of an Ebola prevention campaign in Freetown, Sierra Leone. Michael Duff/AP hide caption
Members of a Red Cross burial team are disinfected after removing the body of an apparent Ebola victim from a home in Pendembu, Sierra Leone. Tommy Trenchard for NPR hide caption
A nurse helps a health worker put on protective gear before treating Ebola patients at a clinic in Kailahun, Sierra Leone, in July. Tommy Trenchard for NPR hide caption