Production and preclinical assessment of camelid immunoglobulins against Echis sochureki venom from desert of Rajasthan, India.

Snakebite is a significant cause of death and disability in subsistent farming populations of rural India. Antivenom is the most effective treatment of envenoming and is manufactured from IgG of venom-immunised horses. Because of complex fiscal reasons, the production, testing and delivery of antivenoms designed to treat envenoming by the most medically-important snakes in the region has been questioned time to time. In this study, we report successful immunisation of dromedaries (Camelus dromedarius) against the venom of Indian saw-scaled Viper- Echis carinatus sochureki. This study assessed the specificity and potential of camels immunised with venom of medically most important snake of Western India, the saw-scaled viper (Echis c. sochureki). Using WHO standard pre-clinical in vivo tests the neutralisation of the venom responsible for the lethal, haemorrhagic, coagulant and local necrotizing activities were measured, since these are the most significant effects that characterize envenoming by this species. The anti-venom was found significantly effective in the neutralisation of all these effects tested and thus, revealed further an immunological perspective, that camel IgG anti-venom (monospecific) would be as efficacious as specific equine anti-venoms or even of better choice in treating snake specific envenoming.

The Ebbinghaus retention curve: training does not increase the ability to apply pressure immobilisation in simulated snake bite--implications for snake bite first aid in the developing world.

Pressure immobilisation (PIM) has been recommended for field management of bites by some venomous snakes. A narrow range of pressures under the encompassing wrap is necessary for PIM to limit venom spread. This study sought to evaluate the effect of focused training on volunteers' ability to apply PIM and to retain such skill over time. Forty volunteers were randomly divided into two groups: Group 1 (N=20; controls) received standard written instructions in PIM application; and Group 2 (N=20) received focused instruction during a 4-h training session (including hands-on practice and real-time feedback regarding pressures achieved). After voicing confidence with the technique, volunteers were tested at 1h, 1 day, 3 days and 3 months post training. One-hour post training, no volunteers in the control group were successful in applying PIM with the correct pressure. Twelve volunteers (60%) in Group 2 achieved target pressures 1h after training. However, there was rapid loss of ability to apply PIM correctly by Group 2, falling to just 25% success at 3 days, with little further deterioration at 3 months. Neither written instructions nor intense training with feedback adequately prepares individuals to apply PIM with correct pressures under the wrap.

Rediscovery of severe saw-scaled viper (Echis sochureki) envenoming in the Thar desert region of Rajasthan, India.

OBJECTIVES: In India, venomous snakebite remains an enigma. Although ineffective first aid treatments that are centuries old continue to be used by people bitten by snakes, important factual information, such as the importance and uniqueness of bites by the northern saw-scaled viper (Echis sochureki), has been largely lost and forgotten. In this paper, we report the first systematically gathered data on the clinical course of envenoming by E sochureki in Rajasthan, India. Clinical information is reported on 12 victims bitten by definitively identified E sochureki, and 2 clinical cases are described in greater detail to illustrate the severity of envenoming by this snake. METHODS: A data collection form was developed and used to prospectively gather clinical information regarding patients who were bitten by E sochureki and who brought the dead snake with them to hospital. All snakes were definitively identified by an experienced herpetologist. Information on symptoms and signs, management (both first aid and hospital), and outcomes was collected. RESULTS: All 12 victims had evidence of systemic envenoming, including abnormal 20-minute whole blood clotting tests (with systemic bleeding in 7). All received polyvalent antivenom made, in part, with Echis carinatus venom from southern India. Antivenom was relatively ineffective in restoring coagulation to these patients. All patients survived, although 1 patient suffered an intracranial bleed with residual hemiparesis. CONCLUSIONS: Echis sochureki causes severe bites in Rajasthan. Work needs to be done to alter the first aid practices used for snakebites in this area, to encourage more rapid presentation to hospital, and to develop antivenom that is more effective against E sochureki.