Identification of cobra and viper bites in southern India using enzyme-linked immunosorbent assay.

Introduction: Snakebite-related deaths are major concerns in populations worldwide that lack access to medical care. Current treatment of snakebites includes administration of polyspecific and polyvalent heterologous equine antiserum. Swift diagnosis of the species of snake responsible is essential to initiate a specific treatment.

Methods: We generated murine monoclonal and rabbit polyclonal antibodies against the venom of the 3 most common venomous snakes in southern India: the Russell viper, the saw-scaled viper, and the Indian cobra. We developed an enzyme-linked immunosorbent assay to distinguish the snake by analyzing the exudates from the snakebite wound.

Results: Monoclonal antibody EC3 reacts specifically with a 45- to 50-kDa venom protein of the saw-scaled viper, antibody NNH6 reacts with 12-kDa venom protein of the Indian cobra, and antibody RVV20 reacts with a 16-kDa venom protein of the Russell viper. We tested the exudates from snakebite wounds in 24 consecutive patients admitted to the Tirunelveli Medical College Hospital with snakebite. Our assay detected 18 patients with Russell viper bite and 1 each for cobra and saw-scaled viper.

Discussion: Our study shows the feasibility of an enzyme-linked immunosorbent assay-based method to identify the 3 major venomous snakes in southern India and holds promise for prompt administration of snake-specific and mechanism-based treatment.