ABSTRACT
Introduction
The ‘Big Four’ venomous snakes – Daboia russelii, Naja naja, Bungarus caeruleus, and Echis carinatus – are primarily responsible for the majority of snake envenomation in India. Several other lesser-known venomous snake species also inflict severe envenomation in the country.
Areas covered
A comprehensive analysis of the venom proteome composition of the ‘Big Four’ and other medically important venomous snakes of India and the effect of regional variation in venom composition on immunorecognition and/or neutralization by commercial antivenom was undertaken by searching the literature (from 1985 to date) available in large public databases. Further, mass spectrometric identification of poorly immunogenic toxins of snake venom (against which commercial polyvalent antivenom contains a significantly lower proportion of antibodies) and its impact on antivenom therapy against snakebite are discussed. The application of mass spectrometry to identify protein (toxin) complexes as well as drug prototypes from Indian snake venoms and the clinical importance of such studies are also highlighted.
Expert opinion
Further detailed clinical and proteomic research is warranted to better understand the effects of regional snake venom composition on the clinical manifestation of envenomation and antivenom therapy and to improve the production of antibodies against poorly immunogenic venom components.
Article highlights
The incidence of snakebites and related mortality in the Indian subcontinent is highest in the world, and the ‘Big Four’ venomous snakes of India are responsible for the majority of these bites and associated moralities.
The ‘Big Four’ snakes are not equally distributed in different parts of the country. For example, D. russelii and N. naja are rarely found in the north-eastern part of India, while E. carinatus is restricted only to southern India and western India. Further, apart from the ‘Big Four’ venomous snakes, other species of medically important venomous snakes are present in the country and are responsible for snakebite injuries and deaths; however, they are grossly neglected and specific antivenoms are not available, raising concerns for the treatment of such envenomation.
The analysis of snake venom proteomes provides useful in-depth information for understanding the disparity in the pathophysiology of snake envenomation due to geographical and species-specific variation of their venom composition. The proteomic data along with advanced clinical research on snake envenomation will be extremely valuable for providing better treatment against snakebite in India.
Mass spectrometric analysis has also contributed significantly to the identification and quantification of poor or partially immunogenic Indian snake venom toxins against which a lower proportion of antibodies are present in commercial PAV. This is one of the key reasons for the partial effectiveness of PAV in neutralizing the major toxins of ‘Big Four’ snake venoms.
There is a desperate need for new and improved PAV for the treatment of snakebite victims.
Declaration of interest
A. Chanda has received a fellowship project grant from DBT BIRAC PACE.
The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.
Reviewer disclosures
Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.