12-18 July 2013 #664

An ounce of venom

Public health importance of snake bite has been largely ignored by medical science
Dhanvantari by Buddha Basnyat, MD

In Kathmandu we worry about leech bites in the summer, but imagine how much more frightening and deadly a snake bite is. Many of us may not appreciate the fact that venomous snakebite is clearly an occupational hazard for our farmers in the Tarai especially in the summer months. South and South East Asia have been identified as having the highest number of snakebites per year. Conservative estimates would suggest that in Nepal there are about 20, 000 bites and 1000 fatalities, almost all in the Tarai.

Unfortunately, because snakebite primarily affects impoverished inhabitants, prevention, and medical management have been neglected. Furthermore there is a dearth of information. For example, many Nepali doctors will consult Western textbooks to treat snakebites; unfortunately treatment of pit viper snakebites from the Sonoran desert in Arizona, USA is going to be significantly different for Nepali snakebites.

Russell’s Vipers, Kraits, and Cobras are the three well recognised types of venomous snakes in Nepal. While Kraits and Cobras cause more of a neurological and breathing problem, viper bites seem to cause acute kidney or blood problems.

Dr Sanjib Sharma of the BP Koirala Institute in Dharan, who has published impressively about snakebites from Nepal in international, peer-reviewed journals, has shown that prompt motorcycle transport to a proper health facility by community volunteers in a Tarai village setting can save lives. At the health facility Sharma had trained personnel ready to administer anti snake venom and provide artificial ventilation when necessary.

Offering rewards for killing venomous snakes has been used as a method of preventing snakebites, but the ecological impact may be trimental as snakes keep the rodent population in check and help with agriculture. Knowing the behaviour pattern of the reptiles is far more helpful in prevention.

Russell’s vipers are so common in paddy fields that farmers would do well to wear proper footwear all the time. The Kraits seem to mostly bite at night when people are sleeping. Since most Tarai residents sleep on floors using mosquito nets can definitely save lives.

It can be argued that the public health importance of snake bite has been largely ignored by medical science. Clearly one reason for this is that the vast burden of illness is in poor, tropical countries like ours. But snake venoms are indeed rich in proteins and peptide toxins that have specificity for a wide range of tissues receptors which makes these venoms attractive for new drug designs and could be potentially interesting for pharmaceutical companies in affluent countries. Clearly better documentation of snakebites and increased collaboration between clinicians, epidemiologists, and toxinologists would be very helpful in the prevention and treatment of this problem.