Snakebite not a cause for Chronic Kidney Disease, study reveals

By Ifham Nizam

Snakebite is not a cause of the Chronic Kidney Disease of Unknown Aetiology (CKDu) in Sri Lanka, a latest study reveals.Lead researcher of the project Prof. Anjana Silva of the Rajarata Medical Faculty told The Island: “We have so far investigated in depth how snakebite causes paralysis in humans, the effectiveness of anti- venom for treating these patients as well as affordable tests to detect snakebite at the bedside and other long-term effects of snakebite.”

Prof. Silva says there are still many things that the team is not clear about, relating to snakebite so they need to continue the studies in the long run not only to understand more about snakebite but also to make a real improvement in the treatment and prevention of this unfortunate, preventable health hazard

Chronic Interstitial Nephritis of Agricultural Communities (CINAC), also known as Chronic Kidney Disease of Unknown Etiology (CKDu), has been a major health issue in Sri Lanka, and has claimed many lives, especially in the North Central Province, and other agricultural areas.

Although the exact cause of this ‘mysterious’ disease has not been elucidated, several hypothesis, including a mix of possible causes, such as water, agricultural activities, agrochemicals, heavy metals, snakebite and heat stress, have been previously attributed by scientists.

A recent research study, by a team of researchers from the Faculty of Medicine and Allied Sciences of Rajarata University, published in a leading medical journal, Clinical Toxicology, revealed that snakebite is unlike to be a cause of CINAC or CKDu in Sri Lanka. This study was conducted as a part of the PhD study of Dr. Subodha Waiddyanatha, where she followed up 199 snakebite patients, four years after the snakebite, and 168 patients, one year after the snakebite.

“At the time of snakebite, we have collected all the information of these patients, including the data on their kidney function. We compared this data with their kidney function, one and four years after the snakebite, and found no evidence of any association of venomous snakebite, with reduced kidney function. We found that those patients who had kidney failure after the snakebite, completely recovered when we studied them one and four years later,” Dr. Waiddyanatha said.

She said that a small number of patients, who had reduced kidney function, at the follow up, had clearly identifiable other causes of poor kidney function, such as diabetes and hypertension. This means that a snakebite is unlikely to be a cause of CINAC or CKDu in Sri Lanka. “However, we still need to closely monitor a large number of patients who develop severe kidney failure, after snakebite, to clearly understand how many of them could have reduced renal functions in the long run,” Dr. Waiddyanatha added.

“This study was conducted as a part of ‘Anuradhapura Snakebite Cohort’, probably the largest snakebite research study in the world, that was started in 2012 by a team of researchers from the Rajarata Medical Faculty that included Prof. Sisira Siribaddana, Dr. Senaka Pilapitya and myself, in collaboration with one of the foremost snakebite researchers in the world, Professor Geoffrey Isbister from Newcastle University, Australia. South Asian Clinical Toxicology Research Collaboration was instrumental in providing logistics for the study”, she said.