Associated Press photographer Esteban Felix Tells the story behind the photos.
The workers who cut sugarcane and other crops in the sweltering coastal lowlands of Central America are being hit by an epidemic that is killing thousands of people a year. From Panama to southern Mexico, laborers are coming down with kidney failure at rates unseen virtually anywhere else in the world.
Families and villages are being devastated by the loss of nearly entire generations of men.
Since 2000, chronic kidney disease has killed more than 24,000 people in El Salvador and Nicaragua, the two countries that are by far the worst hit by the disease.
Rigorous scientific investigation has only just begun in the communities hit by the epidemic, and relatively few facts have been established, but scientists are coming up with what they believe to be a credible hypothesis.
They say the roots of the epidemic appear to lie in the grueling nature of the work performed by its victims.
They labor hour after hour without enough water in blazing temperatures, pushing their bodies through repeated bouts of extreme dehydration and heat stress for years on end. Many start as young as 10. The punishing routine appears to be a key part of some previously unknown trigger of chronic kidney disease, which is normally caused by diabetes and high-blood pressure.
Associated Press Photographer Esteban Felix spent weeks in Chichigalpa, Nicaragua, one of the worst-affected communities, documenting the human toll of this epidemic. There, one of four men has symptoms of chronic kidney disease, which floods the body with toxins, causing weakness, cramps, headaches, vomiting, shortness of breath, and, in the most serious cases, death.