Children play in the West Point neighborhood of Monrovia last week. West Point has been hit hard by Ebola. So local leaders formed their own Ebola task force, which goes door to door looking for cases. John Moore/Getty Images hide caption

itoggle caption John Moore/Getty Images

A woman on the L train in New York City last week covers her face, fearful because a doctor with Ebola rode the train days earlier. Epidemiologists say people on the subway were not at risk. Stephen Nessen /WNYC hide caption

itoggle caption Stephen Nessen /WNYC

A security man takes visitors' temperatures Wednesday at the Transcorp Hilton hotel in Abuja, Nigeria, about 400 miles north of Port Harcourt. Afolabi Sotunde/Reuters/Landov hide caption

itoggle caption Afolabi Sotunde/Reuters/Landov

Kenyan health officials take the temperatures of passengers arriving at the Nairobi airport on Thursday. Kenya has no reported cases of Ebola, but it's a transportation hub and so is on alert. Simon Maina/AFP/Getty Images hide caption

itoggle caption Simon Maina/AFP/Getty Images

Average life expectancy around the world has ticked up over the past twenty years. Here it's shown for men in 2009. The extremes are in dark green and dark red, which represent 78 to 82 years old and less than 66 years old, respectively. Courtesy of the Institute for Health Metrics and Evaluation hide caption

itoggle caption Courtesy of the Institute for Health Metrics and Evaluation