Loved ones express their grief at the burial of Ramon Romero Ramirez in Chichigalpa, Nicaragua, January 2013. The 36-year-old died of chronic kidney disease after working in the sugar cane fields for 12 years. Ramirez is part of a steady procession of deaths among cane workers. Ed Kashi/VII hide caption

itoggle caption Ed Kashi/VII

By ensuring vaccines are invented and distributed, Bill Gates says, his foundation is dramatically reducing the number of childhood deaths in poor countries. Marie McGrory/NPR hide caption

itoggle caption Marie McGrory/NPR

An Egyptian Muslim prays during a ritual in Mina, Saudi Arabia, October 2013. Some people wore masks during the hajj pilgrimage last year to protect against the Middle East Respiratory Syndrome. Amr Nabil/AP hide caption

itoggle caption Amr Nabil/AP

Gado Labbo holds her 5-year-old son, Yusuf, at a clinic in Dareta, Nigeria. In 2010, when Yusuf first entered the clinic, he had a blood lead level 30 times higher than the amount the Centers for Disease Control and Prevention considers dangerous. David Gilkey/NPR hide caption

itoggle caption David Gilkey/NPR

Chemist Facundo Fernandez of the Georgia Institute of Technology tested morning-after pills collected from 15 different pharmacies in Lima, Peru. Rob Felt/Georgia Tech hide caption

itoggle caption Rob Felt/Georgia Tech

A child receives a polio vaccine Sunday in Kano, Nigeria. The country is the primary source of the virus in Africa but appears to be making progress against the disease; the current outbreak in Cameroon that has spread to Equatorial Guinea came by way of Chad, not Nigeria. Sunday Alamba/AP hide caption

itoggle caption Sunday Alamba/AP

Street vendors sell chickens at a market in Phnom Penh, Cambodia, in early 2013. Last year Cambodia reported more cases of H5N1 bird flu than any other country. Mak Remissa/EPA /LANDOV hide caption

itoggle caption Mak Remissa/EPA /LANDOV

Advocates demonstrate in favor of cheaper generic drugs to treat hepatitis C in New Delhi on March 21. The disease is common among people who are HIV positive. Saurabh Das/AP hide caption

itoggle caption Saurabh Das/AP

The new normal in Guinea is washing hands with a mixture of water and bleach--shown here at the border entrance of Buruntuma, in the Gabu area on Tuesday. Tiago Petinga/EPA /LANDOV hide caption

itoggle caption Tiago Petinga/EPA /LANDOV

A pregnant Somali woman gets a tetanus shot at a clinic in Mogadishu in 2013. The vaccination initiative was launched by the GAVI Alliance, UNICEF and the World Health Organization. Carl de Souza/AFP/Getty Images hide caption

itoggle caption Carl de Souza/AFP/Getty Images

Andrew Witty, CEO of GlaxoSmithKline, says that better control of infectious diseases in Africa is allowing chronic diseases to come to the surface. Mark Lennihan/AP hide caption

itoggle caption Mark Lennihan/AP

A boy waits to get vaccinated at an anti-polio campaign in Moradabad, India. Michaeleen Doucleff/NPR hide caption

itoggle caption Michaeleen Doucleff/NPR