Chichigalpa, Nicaragua: Jesus Ignacio Flores started working when he was 16, labouring long hours on construction sites and in the fields of his country's biggest sugar plantation.
Three years ago his kidneys started to fail and flooded his body with toxins. He became too weak to work, wracked by cramps, headaches and vomiting.
On January 19 he died on the porch of his house. He was 51. His withered body was dressed by his weeping wife, and buried on the edge of Chichigalpa, a town in Nicaragua's sugar-growing heartland, where studies have found more than one in four men showing symptoms of chronic kidney disease.
A mysterious epidemic is devastating the Pacific coast of Central America, killing more than 24,000 people in El Salvador and Nicaragua since 2000 and striking thousands of others with chronic kidney disease at rates unseen virtually anywhere else.
Last year it reached the point where El Salvador's health minister, Dr Maria Isabel Rodriguez, appealed for international help, saying the epidemic was undermining health systems.
Patients, local doctors and activists say they believe the culprit lurks among the agricultural chemicals workers have used for years with virtually none of the protections required in more developed countries. But a growing body of evidence supports a more complicated and counter-intuitive hypothesis.
The roots of the epidemic, scientists say, appear to lie in the gruelling nature of the work performed by its victims, who labour 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 ten. The punishing routine appears to be a key part of some previously unknown trigger of chronic kidney disease. Because hard work and intense heat alone are hardly a phenomenon unique to Central America, some researchers will not rule out manmade factors. But no strong evidence has turned up.
Too spread out
"I think that everything points away from pesticides," said Dr Catharina Wesseling, an occupational and environmental epidemiologist who also is regional director of the Program on Work, Health and Environment in Central America. "It is too multinational, it is too spread out.
"I would place my bet on repeated dehydration, acute attacks every day. That is my bet, my guess, but nothing is proved."
Dr Richard J. Johnson, a kidney specialist at the University of Colorado, Denver, is working with other researchers investigating the cause of the disease. They too suspect chronic dehydration.
"This is a new concept, but there's some evidence supporting it," Johnson said. "There are other ways to damage the kidney. Heavy metals, chemicals, toxins have all been considered, but to date there have been no leading candidates to explain what's going on in Nicaragua ...
"As these possibilities get exhausted, recurrent dehydration is moving up on the list."