Sentinels of the Western Ghats- envenoming by the Malabar pit viper (Craspedocephalus malabaricus)-A sub-analysis of the VENOMS registry

Abstract

Background

Malabar Pit Viper (Craspedocephalus malabaricus), endemic to the Western Ghats of India, is an emerging concern in snakebite envenomation. Despite its increasing recognition as a medically significant species, the absence of a species-specific antivenom and limited epidemiological data hinder effective treatment protocols. This study examines the ecological, clinical, and therapeutic aspects of Malabar pit viper envenomation to bridge knowledge gaps and guide clinical management.

Methodology/principal findings

A retrospective analysis was conducted at a tertiary care centre in Coastal Karnataka, encompassing 16 cases from May 2018 to March 2024. Identification was based on the following method.

• killed or live specimen produced at the hospital.

• photographic/videographic evidence captured of the culprit snake by the patient or witness.

• photographic identification (using standard images of known venomous snakes in the region for patients to identify which snakes it is that they saw biting them).

Seven out of sixteen cases were identified based on photographic identification and other circumstantial evidence like snake description, location and habitat where the patient was bitten. These cases were included on a presumed basis due to the lower quality of evidence available. The remaining nine were reliably confirmed with evidence provided. Clinical presentations included severe local envenomation (100 %), coagulopathy (50 %), and mild renal dysfunction (25 %). Local complications such as severe local effects and compartment syndrome necessitated interventions. A notable trend of prolonged prothrombin time derangement, persisting up to 72 h, was observed in patients with coagulopathy. Additionally, three cases of anaphylaxis were reported following Indian Polyvalent Anti Snake Venom (ASV) administration, underscoring the challenges in its use. Indian Polyvalent ASV demonstrated limited but observable cross-reactivity, improving coagulopathy in some cases. The study identified seasonal and occupational risk factors, with most incidents occurring during monsoon-related agricultural activities. Epidemiological mapping highlighted habitat overlaps between human populations and the species range.

Conclusions/Significance

Malabar Pit Viper envenomation is characterized by distinct local and systemic syndromes, requiring targeted management strategies. While Indian Polyvalent ASV may offer interim relief in severe cases, a species-specific antivenom remains essential. This study emphasizes the importance of advancing research into venom composition, therapeutic cross-reactivity, and regional incidence to develop evidence-based treatment protocols and improve patient outcomes.