Russell's viper (Daboia russelii) is one of India's most dangerous species of snake and is responsible for thousands of bites to humans every year. Photograph by David Williams.
Snakebite envenoming is an important public health problem in India, affecting rural and peri-urban populations. Approximately 46,000 deaths occur annually from snakebite in India, with another 1.4-2.8 million non-fatal cases. These figures, calculated from data collected for the “Indian Million Deaths Study”, are based on surveys of 6,671 randomly selected areas across India, and bear witness to the impact of a Neglected Tropical Disease for which no effective control program currently exists. This data suggests that 82-97% of snakebite fatalities are rural, and that 77% of them occur outside a health facility. Many more deaths (5,000-7,000/month) occur during the monsoon than in the dry season (2,000/month), and the average mortality rate is 3.0-4.5/100,000 persons/year. A study conducted in rural communities in one State (Tamil Nadu) suggested that the numbers may be 3 times higher still, with as many as 10,000 deaths per year occurring there alone. Similarly, a community-based survey of snakebite envenoming in West Bengal found that only 7.2% of all snakebite deaths were officially reported. In that study it was found that only 22.9% of patients attended hospital, and 65.7% of all snakebite deaths in the region were due to the bites of neurotoxic kraits (Bungarus spp.). These studies, and those conducted elsewhere in the developing world, have uncovered a common theme – the longer it takes victims to present to medical care, the higher the mortality rate. Indeed, one study reported an 18% case fatality rate in patients arriving >24 hours post-bite compared to 5% among those who arrived within the first 24 hours.