Snakebite and its socio-economic impact on the rural population of Tamil Nadu, India

Abstract

Background: Snakebite represents a significant health issue worldwide, affecting several million people each year with as many as 95,000 deaths. India is considered to be the country most affected, but much remains unknown about snakebite incidence in this country, its socio-economic impact and how snakebite management could be improved.

Methods/principal findings: We conducted a study within rural villages in Tamil Nadu, India, which combines a household survey (28,494 people) of snakebite incidence with a more detailed survey of victims in order to understand the health and socio-economic effects of the bite, the treatments obtained and their views about future improvements. Our survey suggests that snakebite incidence is higher than previously reported. 3.9% of those surveyed had suffered from snakebite and the number of deaths corresponds to 0.45% of the population. The socio-economic impact of this is very considerable in terms of the treatment costs and the long-term effects on the health and ability of survivors to work. To reduce this, the victims recommended improvements to the accessibility and affordability of antivenom treatment.

Conclusions: Snakebite has a considerable and disproportionate impact on rural populations, particularly in South Asia. This study provides an incentive for researchers and the public to work together to reduce the incidence and improve the outcomes for snake bite victims and their families.

Figure 1. Correlation between rainfall and snakebite incidence.

A. Annual snakebite incidence (blue bars) and rainfall statistics (red line) for Tamil Nadu from 2001–2010 (obtained from the Department of Climate and Rainfall, Government of Tamil Nadu). The correlation coefficient between the number of bites and rainfall is 0.84, the correlation coefficient between number of deaths and rainfall is 0.87 (data not shown). B. Monthly snake bite incidence (blue bars) and average rainfall (red line) for Tamil Nadu in 2010. The monthly rainfall data were obtained from the Hydromet division of the Indian Meteorological Department. The correlation coefficient between the monthly snake bite distribution and the distribution of rainfall is 0.5.

Figure 2. Distribution of snake bites by age group.

The red bars show the % of the total number of people which are in each age group identified in the study population. The blue bars show the % of the population of that age group who have been bitten by snakes.

Figure 3. Distribution of snake bites by type of snake.

Where the snake species was not identified due to the inability of people to identify the snake, or the bite occurred in dark, these are classified as ‘unknown’.