"It goes by many names, but around here they call it 'the malady of the sugar cane," writes Will Storr in the Guardian. A quiet epidemic has been preying on Central American sugar field laborers for decades, and it is killing more and more each year. "Between 2005 and 2009, incidents in El Salvador rose by 26%. By 2011 the chronic kidney disease (CKD) had become the country's second-biggest killer of men." But what exactly is it?