This illustration depicts a yellow fever victim in a Jefferson Street home in Memphis. It's from a series of images entitled "The Great Yellow Fever Scourge — Incidents Of Its Horrors In The Most Fatal District Of The Southern States." Bettmann Archive hide caption
These are insect cells infected with the Guaico Culex virus. The different colors denote cells infected with different pieces of the virus. Only the brown-colored cells are infectious, because they contain the complete virus. Michael Lindquist/Cell Press hide caption
The countries with the tallest and shortest 18-year-old men and women in the world, according to a new study. Leif Parsons for NPR hide caption
Women from a traditional sea-harvesting community fish in Mozambique. Michael D. Kock/Nature hide caption
A screwworm larva grasps the flesh in a wound with its mouth's tusklike protrusions and screws itself in. Science Source hide caption
A horse and mules thresh wheat in Spain. The World Organisation for Animal Health has adopted the first set of global standards to ensure equine welfare. De Agostini/Getty Images hide caption
They're guys who stand up for women's rights. Left to right: Patrick Segawa and Steven Twinomugisha of Uganda, Mark Gachagua of Kenya and Bryan Eric Mallari of the Philippines at the Women Deliver conference. Allison Shelley for NPR hide caption
World Health Organization head Dr. Margaret Chan delivering a speech in March of this year at a summit in Lyon, France. Francois Mori/AP hide caption
Children wade in a flooded street last June in Leiyang, China. ChinaFotoPress/Getty Images hide caption
Dr. Forster Amponsah is one of two surgeons at the Koforidua Regional Hospital in Ghana. Trained in Cuba, he came home because he felt his skills were needed in Africa. Jason Beaubien/NPR hide caption
Bed nets have protected Mary Akye and her five children from malaria-carrying mosquitoes in Ghana. Karen Kasmauski/Corbis hide caption
A pneumococcal vaccine is delivered via motorcycle in Kenya. Evelyn Hochstein/Courtesy of Gavi hide caption
A midwife cuts the umbilical cord of a newborn baby in a hospital in South Sudan. JM Lopez/AFP/Getty Images hide caption