The Impact of Snakebites on Kidneys: A Major Health Concern in India

 Snakebites are a significant health problem in India, particularly in rural areas where farming and labor-intensive work are common. Every year, around 50,000 people die from snakebites in India, out of an estimated 3–4 million cases. This accounts for about half of all snakebite deaths worldwide. Yet, the actual burden is likely much higher, as many snakebite victims do not report to hospitals and clinics, often turning to traditional healers instead. Therefore, understanding the effects of snakebite envenoming on the kidneys and recognizing the symptoms can help save lives and kidneys.

The “Big Four” Snakes and Their Effects

In India, 90% of snakebites are caused by four species:

• Common Krait
• Indian Cobra
• Russell’s Viper
• Saw-Scaled Viper

These snakes are highly venomous, and their bites can cause a range of complications, including acute kidney injury (AKI). Snake venom is a complex mixture of proteins, including enzymes, toxins, and other harmful molecules. These substances can directly affect the kidneys and other organs, leading to life-threatening conditions like kidney failure. The Russell’s viper and the saw-scaled viper are particularly known for causing severe damage to the kidneys.

Kidney involvement

AKI is one of the most common complications following a snakebite. The incidence of AKI varies depending on the type of snake and the severity of the bite. Studies in India suggest that AKI occurs in 5% to 29% of snakebite cases. It can develop as quickly as a few hours after the bite or take up to four days to manifest.

How Snake Venom Affects the Kidneys

 Kidney involvement happens through several mechanisms:

• The venom affects hemodynamic changes (blood flow and pressure changes) in the body, leading to kidney damage. Low blood pressure and hemorrhaging reduce the amount of blood reaching the kidneys, which can result in kidney ischemia (lack of oxygen).
• The venom can destroy red blood cells (hemolysis) and muscle cells (rhabdomyolysis). The breakdown products from these cells, such as hemoglobin and myoglobin, can clog the kidneys, leading to acute damage.
• The toxins in the venom can directly attack kidney cells
• A kidney biopsy can show acute tubular necrosis, interstitial nephritis, cast nephropathy glomerulonephritis, and cortical necrosis.

 Symptoms of Kidney Damage from Snakebite

 The symptoms of AKI following a snakebite can vary, but some key signs to watch for include:

• Oliguria or Anuria (Reduced or absent urine output)
• Hematuria (Blood in the urine)
• Dark-Colored Urine (This can be a sign of hemoglobinuria or myoglobinuria, both of which are linked to kidney injury)
• Swelling: Fluid retention due to poor kidney function can lead to swelling in the legs, arms, and face.
• Nausea and Vomiting: These symptoms can result from the accumulation of waste products in the blood due to impaired kidney function.

Treatment of Snakebite-Induced AKI

The treatment for AKI caused by snakebite is similar to that for AKI from other causes. Early administration of antivenom is crucial to neutralize the venom and prevent further damage. A longer delay between the snakebite and administration of antivenom may lead to more impact of venom on the kidneys. Many victims seek traditional healing methods before going to the hospital which can worsen the condition. Access to trained healthcare providers and proper medical facilities remains a challenge in rural areas of India, where snakebites are most common.

In addition to antivenom, other treatments include:

Hydration: Ensuring the victim is well-hydrated can help maintain blood flow to the kidneys and prevent further damage.

Dialysis: In severe cases of AKI, where kidney function is severely impaired, dialysis may be required.

Chronic Kidney Disease (CKD) Following Snakebite

In some cases, AKI caused by snakebites can lead to long-term kidney problems, such as chronic kidney disease. Studies have shown that around 37% of patients who suffer from AKI after a snakebite might develop CKD within one year. CKD is permanent kidney damage and is a serious issue, it requires long-term treatment, including dialysis or even a kidney transplant.

 Preventing kidney damage after a snakebite involves quick and effective medical intervention. Here are some key steps to follow:

• Seek Immediate Medical Help: Do not rely on traditional or home remedies. Snakebite victims should be taken to a hospital as soon as possible for the administration of antivenom (if indicated).
• Avoid Incisions and Suction: These practices, often used in traditional first aid, can do more harm than good and should be avoided.
• Maintain Hydration: Keeping the victim hydrated can help reduce the risk of kidney damage.
• Educate Rural Communities: Education about the dangers of snakebites and the importance of seeking medical help is critical. Many rural communities lack the knowledge and resources to deal with snakebite emergencies effectively.
• Public awareness, improved healthcare access, availability of ASV, and education on snakebite first aid can significantly reduce the burden of this neglected tropical disease.

For snakebite victims, timely treatment and the right therapeutic approach can make the difference between life and death, especially in preventing mortalities and long-term complications like CKD. By raising awareness and improving healthcare responses, we can reduce the toll of snakebites on individuals, and families.
Important reference

1. Kanjanabuch T, Sitprija V. Snakebite nephrotoxicity in Asia. Semin Nephrol. 2008;28(4):363–72.
2. Simpson ID, Norris RL. Snakes of medical importance in India: is the concept of the Big 4 still relevant and useful? Wilderness Environ Med. 2007;18(1):2–9.
3. Kaaviya R, Vadivelan M, Balamurugan N, Parameswaran S, Thabah M. Community acquired AKI: a prospective observational study from a tertiary level hospital in Southern India. Indian J Nephrol. 2019;29(4):254.
4. WHO highlights the critical need for life-saving antivenoms. [Internet] Geneva: World Health Organization. ; 2014 Available from: http://www.who.int/mediacentre/news/notes/2010/antivenoms_20100504/en/ . Accessed 14 Mar 2021
5. Vikrant S, Jaryal A, Parashar A. Clinicopathological spectrum of snake bite-induced acute kidney injury from India. World J Nephrol. 2017;6(3):150–61.
6. Priyamvada PS, Jaswanth C, Zachariah B, Haridasan S, Parameswaran S, Swaminathan RP. Prognosis and long-term outcomes of acute kidney injury due to snake envenomation. Clin Kidney J. 2020;13(4):564–70.
7. Meena, P., Bhargava, V., Gupta, P. et al. The kidney histopathological spectrum of patients with kidney injury following snakebite envenomation in India: a scoping review of five decades. BMC Nephrol 25, 112 (2024). https://doi.org/10.1186/s12882-024-03508-y