A patient at the Texas Health Presbyterian Hospital in Dallas has a confirmed case of Ebola, the Centers for Disease Control and Prevention says. He is being treated and kept in strict isolation. LM Otero/AP hide caption

itoggle caption LM Otero/AP

Adrian Hill, director of the Jenner Institute and chief investigator of the trials with an Ebola vaccine his organization developed, holds a vial of the vaccine. Steve Parsons/WPA Pool/Getty Images hide caption

itoggle caption Steve Parsons/WPA Pool/Getty Images

Boys show off their four-legged friends at a rabies vaccination drive set up by the Serengeti Health Initiative in the Bariadi District of Tanzania. Anna Czupryna/Courtesy of Serengeti Health Initiative hide caption

itoggle caption Anna Czupryna/Courtesy of Serengeti Health Initiative

Some potential new Ebola drugs will be tested at treatment centers like this one run by Doctors Without Borders near Monrovia. John Moore/Getty Images hide caption

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Liberian physician Martha Zarway continues work in a temporary clinic while her original facility is disinfected. Tommy Trenchard for NPR hide caption

itoggle caption Tommy Trenchard for NPR

A poultry processing plant in France. Europe banned treating chicken carcasses with chlorine in the 1990s out of fear that it could cause cancer. Christophe Di Pascale/Corbis hide caption

itoggle caption Christophe Di Pascale/Corbis

Daniela Chavarriaga holds her daughter Emma as Dr. Jose Rosa-Olivares administers a measles vaccination at Miami Children's Hospital. Joe Raedle/Getty Images hide caption

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As the mayor of Cali, Colombia, epidemiologist Rodrigo Guerrero (left) meets with the police once a week to review murder statistics. Courtesy of Prensa Alcaldía de Calí hide caption

itoggle caption Courtesy of Prensa Alcaldía de Calí