Kesava Rao, 45, has chronic kidney disease of unknown etiology (CKDu) and depends on dialysis to survive. “Every week I undergo dialysis, 4 weeks a month,” Rao says. A soft-spoken man with a ready smile, Rao has worked all his life on construction sites or coconut farms. He lived a healthy life and hardly ever saw a doctor, he says, until a fever led to an exam and his diagnosis. Rao didn’t have diabetes or, until his kidneys failed, hypertension, the two main causes of chronic kidney disease worldwide. Nor do most of the other villagers who have gathered here, all chronic kidney disease patients, waiting to get a free blood test for creatinine, a metabolite and a proxy for kidney function, and give samples of urine and blood for research.
This region in coastal Andhra Pradesh is at the heart of what local doctors and media are calling a CKDu epidemic. There is little rigorous prevalence data, but unpublished studies by Gangadhar Taduri, a nephrologist at the Nizam’s Institute of Medical Sciences in Hyderabad, in the neighboring state of Telangana, suggest the disease affects 15% to 18% of the population in this agricultural region, known for rice, cashews, and coconuts. Unlike the more common kind of CKD, seen mostly in the elderly in urban areas, CKDu appears to be a rural disease, affecting farm workers, the majority of them men between their 30s and 50s. “It is a problem of disadvantaged populations,” says Taduri, who is leading the team of researchers in the village.
A rash of similar outbreaks in other countries has underscored that it is a global problem. Some rice-growing regions of Sri Lanka have their own epidemic, and the disease is rampant in sugar-producing regions of Mexico and Central America. It has also been reported in Egypt. Just about everywhere, prevalence numbers are scarce and uncertain, but “there is a great deal of concern,” says Virginia Weaver, an epidemiologist at Johns Hopkins Bloomberg School of Public Health in Baltimore, Maryland.