- CKDu is a complex health problem with unknown origins
- The disease is especially prevalent among sugarcane workers
- Kidney dialysis and transplants are often too expensive for employees
- Some research on the disease is funded by the sugarcane industry, causing controversy
Juan Salgado was 16 when he started cutting sugarcane, in a town near the Pacific coast of Nicaragua in 1966.
His symptoms began about 35 years later: Fever. Headaches. Poor appetite. Feelings of faintness. For no obvious reason, his kidneys were severely damaged, to the point that doctors said he couldn't do agricultural work anymore. Many of his friends had it worse.
"I know, many, many workers who were colleagues of mine, who have already died, and I know also many who are not capable of working anymore because of the disease," said Salgado, now 65, who worked near the town of Chichigalpa, Nicaragua.
The disease is known by scientists as "chronic kidney disease of unknown origin," or CKDu. In rural communities in Nicaragua, it's "creatinina," the Spanish word for creatinine, a biomarker of kidney strength.
At least 20,000 people have died prematurely from this mysterious disease in Central America in the last two decades, according to one estimate, but the real scope of the problem is unknown. The illness is not related to diabetes or hypertension -- drivers of kidney disease in the United States -- and affects primarily young men.
The disease is concentrated on the Pacific Coast in male agricultural workers, especially those cutting sugarcane. El Salvador, Nicaragua and Costa Rica seem to be hotbeds of the illness.
Scientists believe that a multitude of factors could be contributing to the disease, but that there's likely at least one factor that is job-related. Making matters tricky, the sugarcane industry has been a provider of funding for major studies on the illness, raising concerns that companies could be influencing the results.
In Salgado's opinion, the Nicaraguan sugarcane industry players "know well the cause of this disease."