Newswise — RESEARCH TRIANGLE PARK, N.C. — An important and mysterious global public health concern is unfolding around chronic kidney disease of unknown origin.

In certain endemic areas in Sri Lanka, more than 15 percent of the population is at risk of developing chronic kidney disease of unknown origin (CKDu), according to Sri Lanka's Ministry of Health and the World Health Organization. The illness is affecting mostly dry-zone areas in countries such as Sri Lanka, India and El Salvador.

"The impact of chronic kidney disease of unknown etiology is growing, while the causes remain unknown," said Myles Elledge, senior director for Global Strategy in RTI's Center for Technology Applications. "More questions than answers have arisen from previous research efforts that tried to identify the disease."

The kidney disease most commonly affects rural residents and agriculture workers, between 30 to 60 years old who have more than 10 years of agriculture experience. Symptoms include fatigue, panting, lack of appetite, nausea and anemia.

Symptoms appear slowly and often not until the later stages of the diseases. Its impact can be traumatic on patients and their families as the ability to work and earn declines, and often low-income families' resources are stretched to provide care, and lack access to dialysis treatment.

A recent RTI research brief recommends coordinated global health research efforts and more robust disease registries/reporting systems to address chronic kidney disease of unknown origin.

RTI researchers are currently working to try to understand this unique chronic kidney disease in Sri Lanka, as part of the Non-Communicable Disease Grand Challenge project. RTI is collaborating with the University of Kelaniya in Colombo, Sri Lanka, to conduct lab sample analysis and expanded field study design.

Although the causes remain unknown, the RTI brief suggests that the illness is linked to multiple conditions including environmental factors, diet and nutritional practices, and genetics. Risk factors include sun exposure, heat stress, dehydration, and low elevation. Pesticides and fertilizers containing heavy metals are also a concern.

"CKDu can devastate the social and economic-wellbeing of a country as patients suffer a decline in productivity, reduction in quality of life, monetary loss, decline in earning potential, and an inability to sufficiently provide for their families," Elledge said. "To improve these health and economic outcomes, a collaborative approach is needed to identify causes by working across health, agriculture, and environmental agencies."

In Sri Lanka, chronic kidney disease of unknown origin cases have increased to epidemic levels in the past 10 years. Many gaps in diagnosis, data collection and recordkeeping exist despite disease registries designed to improve data collection.

To address this growing epidemic, a new research brief by multidisciplinary RTI researchers offers the following key recommendations:

-Standardize and strengthen disease registries and reporting systems for cases of chronic kidney disease and chronic kidney disease of unknown origin-Strengthen the national environmental toxicology and epidemiological networks by supporting open, transparent exchange of information-Ensure data quality by expanding and harmonizing laboratory equipment, protocols and training-Assess the economic impact of the disease to help quantify the costs and societal impact Countries that have seen an increase in patients affected by the illness include Nicaragua, El Salvador, Guatemala, Mexico, Bulgaria, Croatia, Serbia, India and Sri Lanka.

A recent article in The Lancet further highlights the global health mystery.