Snake bites in the hills of north India.

ABSTRACT

BACKGROUND: Snake bites are a common cause of morbidity and mortality in the hills. The risk of snake bite is high due to the presence of a huge herpeto fauna flourishing in a favourable climate--low environmental temperature and heavy rainfall. In India, there are 236 species of snakes of which four are dangerously venomous. This study was undertaken to determine the risk factors exposing the population to snake bite and the common types of snakes causing them. METHODS: We studied 243 patients of snake bite over a period of 24 months. All patients were examined for evidence of snake bite and, where possible, the snakes were identified based on description, identification (if the snake was brought) and symptoms of envenomation. RESULTS: Seasonal variation in snake bite was seen, with a peak in the months of August and September. No bites were recorded in December, January and February. Eighty-four per cent of the bites were on the hands and feet (up to the ankle). Bites on the hand were more common in females with a left hand preponderance (3.5 times higher). The age group most affected was between 11 and 40 years (73.7%). Most bites occurred while the person was cutting grass, working in the fields or walking in the hills (75.3%). Snake bites while sleeping were at uncommon sites. Non-poisonous snakes were the most common (90.5%). Kraits caused 60% of bites with envenomation. CONCLUSION: Snake bites occur frequently in the hills of Himachal Pradesh. Although snake bites are a cause for concern, most of them are caused by non-poisonous snakes.