In north central Sri Lanka, where the disease strikes 15% of the population, Buddhist monks donate kidneys to strangers. An island in Nicaragua is known as the Island of the Widows because so many of its young men have died.
The mystery disease, Chronic Kidney Disease of Unspecified Origin (CKDu), is killing more people than diabetes, HIV/AIDS and leukemia combined. More than 16,000 men have died from CKDu between 2005 and 2009.
The victims are typically young male farm workers doing backbreaking work in very hot weather. In one case, Maudiel Martinez of Nicaragua developed CKDu at the age of 17, after working in the sugarcane fields for three years. His father also died of the disease.
The World Health Organization blames heavy metal poisoning, likely from food, but many independent experts suspect that CKDu is a work-related illness caused by the deadly combination of pesticides and backbreaking labor in the extreme heat.
Read the Backstory, our Q&A with the winners
Sasha Chavkin is an investigative reporter based in New York City. He is currently covering political advertising in the 2012 elections in "The Ad Wars," a regular column for the Columbia Journalism Review. He has previously written for ProPublica and the New York World.
Anna Maria Barry-Jester is a multimedia journalist based in New Delhi, India. She previously worked as a producer for an award-winning global health series at ABC News. She holds a Master of Public Health from Columbia University. She has been researching and documenting chronic kidney disease since 2008.
Ronnie Greene is a senior investigative reporter and editor with the Center for Public Integrity. Earlier this month, he received an Emmy Award for his investigation, produced in partnership with ABC News, into the U.S. government's green energy spending. Before joining the Center, he was the investigations and government editor for the Miami Herald; his last Herald project, "Neglected to Death," was a Pulitzer Prize "Finalist for Public Service."
The Sidney Hillman Foundation honors excellence in journalism in service of the common good. Judges are Rose Arce, Hendrik Hertzberg, Katrina vanden Heuvel, Harold Meyerson, Susan Meiselas, and Lindsay Beyerstein.
The Sidney Award is given once a month to an outstanding piece of journalism about social or economic injustice, by the Sidney Hillman Foundation, which also awards the annual Hillman Prizes every spring. Winners of the Sidney receive a certificate designed by New Yorker cartoonist, Edward Sorel, a $500 honorarium and a bottle of union-made wine.