Hyderabad scientists call for region-specific snake antivenom to improve bite treatment

Scientists at Hyderabad's CCMB-LaCONES have called for region-specific snake antivenoms, citing research showing that venom profiles vary geographically. Their findings indicate that standard polyvalent antivenom may not effectively neutralise venom from regional krait populations in North-East India.

Hyderabad: It may sound strange, but according to top scientists from Hyderabad, the country needs a region-specific snake antivenom optimized for snake bite victims based on their geographical location.

This means that the present-day standard pan-India antisnake venom will not guarantee protection for a snake bite victim from the North-East or Deccan plateau or someplace else.
At present, if a patient is bitten by a venomous snake anywhere from Kanyakumari to Assam, doctors administer a standard polyvalent Anti-Snake Venom (ASV).

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However, recent research by senior scientist Dr. Karthikeyan Vasudevan at Hyderabad-based Centre for Cellular and Molecular Biology’s Laboratory for the Conservation of Endangered Species (LaCONES-CCMB), has indicated snake venom evolves based on location.

The research shows that snakes do not produce a standard cocktail of toxins and their venom profiles shift based on where they are located, the local climate, and the specific prey species such as rodents, lizards, or other snakes that are available in their local habitats.

The researchers also found out that the standard polyvalent antivenom is not effective at all in neutralising the venom of regional krait populations in North-East India.
The process of manufacturing antivenom itself is based on standard practice. Almost all the commercial antivenom in the country is manufactured by immunizing horses with venom extracted from only four species of snakes from southern and western India.

The four snakes species include Spectacled Cobra (Naja naja), Common Krait (Bungarus caeruleus), Russell’s Viper (Daboia russelii) and Saw-scaled Viper (Echis carinatus) to immunise horses and then extract antivenom.

A patient bitten by a regional krait may be rushed to a local clinic and receive the correct number of vials of standard snake antivenom.

However, because the horse antibodies inside the vial were never raised against those specific regional toxin variants, they cannot halt the progress of neurotoxicity, respiratory paralysis, or internal hemorrhage, the CCMB-LaCONES study determined.

Clinicians are often left puzzled as patients deteriorate despite aggressive treatment, unaware that the molecular mechanism between the antivenom and the venom has broken down, the researchers said.

The findings from the CCMB-LaCONES team has underscored the urgent public health need that the country needs region-specific or geographically optimized antivenoms.

• Standard pan-Indian polyvalent antivenom fails to effectively neutralize regional snake venom variants
• Snake venom profiles evolve based on local climate, habitat, and available prey species.
• Present day snake antivenom are ineffective against snake bites in North-East
• Antivenom is manufactured using venom sourced primarily from southern and western Indian populations.
• Snake bite victims can deteriorate despite receiving the correct number of ASV vials
• Horse generated antibodies do not target regional toxin variants.
• Scientists urge development of region-specific, geographically optimized antivenoms
• Four snakes used for antivenomL Spectacled Cobra, Common Krait, Russell’s Viper and Saw-scaled Viper