On the lookout for SARS, an employee checks a baby's temperature at the Ben Gurion Airport in Israel, in 2003. The deadly virus quickly spread around the world once it reached Hong Kong, a central travel hub. Nir Elias/Reuters/Landov hide caption

itoggle caption Nir Elias/Reuters/Landov

A health worker from Doctors Without Borders examines Ebola patient Finda Marie Kamano, 33, at her home in Conakry, Guinea, in April. The outbreak that began in February is still spreading in West Africa. Sylvain Cherkaoui/Cosmos/Courtesy of Doctors Without Borders hide caption

itoggle caption Sylvain Cherkaoui/Cosmos/Courtesy of Doctors Without Borders

Fishermen drag a net in Lake Malawi in 2012. About the size of New Jersey, the lake is home to hundreds of fish species and is considered one of the most biologically diverse lakes in the world. Ding Haitao/Xinhua/Landov hide caption

itoggle caption Ding Haitao/Xinhua/Landov

Contaminated water can spread diseases like cholera and typhoid. A new project aims to provide water filters in the form of an educational book. Soe Than Win/AFP/Getty Images hide caption

itoggle caption Soe Than Win/AFP/Getty Images

Muslim pilgrims wear masks to prevent infection from the Middle East respiratory syndrome in the holy city of Mecca, Saudi Arabia, on Tuesday. Hasan Jamali/AP hide caption

itoggle caption Hasan Jamali/AP

A farmworker in Riyadh, Saudi Arabia, wears a mask to protect against Middle East respiratory syndrome earlier this month. The MERS virus is common in camels. Fayez Nureldine/AFP/Getty Images hide caption

itoggle caption Fayez Nureldine/AFP/Getty Images

Shefali Rani Das, an expectant mother in Bangladesh, has given birth to six children (including 4-year-old Suborna) at home without a doctor. Only three of her babies have survived. Colin Crowley/Save the Children hide caption

itoggle caption Colin Crowley/Save the Children

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