The city of Sao Paolo, Brazil, shot with a fisheye lens. Standards of living are improving not just in the big developing nations like Brazil, but also in smaller countries such as Bangladesh and Ghana. Daniel Incandela/Flickr via Wikimedia Commons hide caption

itoggle caption Daniel Incandela/Flickr via Wikimedia Commons

Many homes that were rebuilt after the earthquake in 2010 are even more dangerous than the original ones. This three-story home was put up after the quake but is already slated for demolition to make way for an 18-unit housing project. David Gilkey/NPR hide caption

itoggle caption David Gilkey/NPR

HIV drugs not only can keep patients healthy but also can stop the sexual transmission of the virus. Here an HIV-positive mother picks up medications at a hospital outside Johannesburg, South Africa. Alexander Joe/AFP/Getty Images hide caption

itoggle caption Alexander Joe/AFP/Getty Images

Workers at the SAE-A textile plant inside the Caracol Industrial Park in northern Haiti. Backers of the project say it could create 60,000 jobs inside the park. David Gilkey/NPR hide caption

itoggle caption David Gilkey/NPR

A Nigerian health commissioner Dr. Sani Malam vaccinates a child for polio during a national immunization drive in Bauchi, Nigeria, last week. Deji Yake/EPA /Landov hide caption

itoggle caption Deji Yake/EPA /Landov

Mont Joli Hotel looks out over Cap-Haitian in northern Haiti. The owner says he's usually fully booked and plans to double the hotel's capacity. Haiti is trying to expand its tourism infrastructure and tap in to the multibillion-dollar Caribbean travel market. David Gilkey/NPR hide caption

itoggle caption David Gilkey/NPR

Jacqueline Syra has been living in the La Piste camp for three years. She says she has no idea when she will be able to leave. David Gilkey/NPR hide caption

itoggle caption David Gilkey/NPR

Chiara Andolina, a malaria researcher in Thailand, feeds her mosquito colony by letting the insects bite her right arm. These mosquitoes are picky and will dine only on live human blood. Ben de la Cruz/NPR hide caption

itoggle caption Ben de la Cruz/NPR

The U.S. Army distributed a monthly pinup calendar to GIs, which encouraged them to protect themselves from malaria-carrying mosquitoes. Cartoon by Frank Mack for the U.S. Army./Courtesy of the Images from the History of Medicine. hide caption

itoggle caption Cartoon by Frank Mack for the U.S. Army./Courtesy of the Images from the History of Medicine.

In rural areas of Myanmar, villagers can buy inexpensive packets of drugs, called Ya Chut, when they have malaria. But these local remedies often don't contain adequate amounts of malaria medicines. Ben de la Cruz/NPR hide caption

itoggle caption Ben de la Cruz/NPR

Dr. Aun Pyae Phyo examines a baby at the Whampa malaria clinic on the Thailand-Myanmar border. Ben de la Cruz/NPR hide caption

itoggle caption Ben de la Cruz/NPR

A boy works at an illegal gold mine in northern Nigeria. Lead from these mines has sickened thousands of children in the region. David Gilkey/NPR hide caption

itoggle caption David Gilkey/NPR