From Nicaragua to Miami, cases of chronic kidney disease of unknown origin (CKDu) share a common setting: sites where agricultural work takes place in severe heat. Independent research on the cause of CKDu points to chemicals used in sugarcane agriculture, the physiological response to intensive work in the heat, and the sugary beverages commonly consumed by laborers. But researchers receiving millions in funds from the Centers for Disease Control and Prevention, the National Institutes of Health, and the Central American sugar industry have failed to discover the disease’s cause—or investigate some of the leading suspects.

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