Russell’s viper (Daboia russelii), a venomous snake responsible for half the deaths due to snakebites in India [Image credits: Chandranuj/ CC BY-SA 4.0]
On a day in June 2020, a father and his two sons finished their dinner and fell asleep in their hut in a remote village in Madhya Pradesh. Little did they know that it would be their last night, for a venomous snake was lurking inside. Come morning, the villagers discovered the three dead due to snakebites. Although an antivenom, given on time, could have saved their lives, it was too late for the three hapless souls.
Incidents of snakebites and resulting deaths are no rarity in India, which accounts for half the world’s deaths due to snakebites. Now, a new study, published in the journal eLife, claims that India has witnessed an estimated 1.2 million deaths due to snakebites between 2001-2020. The study included public health researchers and herpetologists from India, the UK, and Canada. It analysed the trend in deaths due to snakebites between 2001-2014 and extrapolated these numbers for 2015-2020. It also explored the seasonality and other factors affecting deaths due to snakebite.
India is home to many species of venomous snakes, including vipers, cobras and kraits. Dr Romulus Whitaker, a renowned Indian herpetologist and the founder of the Madras Crocodile Bank, gives a long list of such snakes, whose bites could be potentially fatal.
“There are four species of cobras—Spectacled, Monocled, Andaman, and Central Asian Cobra; eight species of kraits—Common, Black, Lesser Black, Andaman, Sind, Wall's, Banded and Himalayan Krait; two sub-species of saw-scaled vipers—Common and Sochurek's, several species of sea snakes and pit vipers, notably the Hump-nosed pit viper,” he says.
The Russell’s viper is the deadliest as it contributes to half the deaths occurring due to snakebites, according to the study. Kraits and cobras follow next.
Trends in snakebite-related deaths in India
The analysis shows that deaths due to snakebites in India, between 2001-2014, stood at about 808,000—amounting to about 4.8 deaths per 100,000 people. Those in the age group of 30-69 years accounted for nearly half of the total deaths. These numbers show that the average risk of an Indian dying from snakebite prematurely before age 70 is approximately 1 in 250. When these numbers were extrapolated to estimate for 2015-2020, they were comparable to the number of deaths due to dengue, another neglected tropical disease.
Figure 1: Percentage of deaths due to snakebites in India between 2001-2014. [Data Source]
The study also identified many hotspots of snakebite deaths in the states of Bihar, Jharkhand, Madhya Pradesh, Odisha, Uttar Pradesh, Andhra Pradesh (including Telangana), Rajasthan and Gujarat. In these areas, the risk of dying was as high as 1 in 100. Almost all snakebite deaths were reported from areas with low elevation.
Most bites occurred in rural areas, where snakes are typically found close to homes because rodents, on which they prey, thrive on the garbage and edible crops around homes. The monsoon months of June to September had almost half of the reported snakebite deaths.
“Rainy months are when snake prey is abundant and snakes are on the move. Human farming activities are at their peak during these months, and hence, snakes and humans are more apt to meet,” elaborates Dr Whitaker.
Figure 2: Spatial distribution of snakebite mortality risk in India for 2004-13 [Image Source]
A neglected health concern
Bites from any of the venomous snakes could cause shock, paralysis, haemorrhage, kidney injury and local tissue damage, and without timely treatment, could turn fatal. The good news, however, is that antivenoms are available against these venoms and could save lives.
“Snakebites kill more people than other tropical diseases and cause more long-term physical and mental disability,” says Dr David Warrell.
He is a professor at the University of Oxford and an expert in tropical medicine. He is also one of the authors of the current study. The World Health Organisation (WHO) has recognised snakebite as a ‘neglected tropical disease’ and calls to halve the number of snakebite-related deaths and disability by 2030.
For years, government figures have underreported snakebite deaths as they included numbers only from public hospitals. There has also been consistent lack of national and international research funding to establish the public health importance of snakebite.
“There is also weak political advocacy on behalf of the main victims who are impoverished agricultural workers and their families. People in power are embarrassed to admit that their countries still suffer from the primaeval environmental scourge of snakebite,” argues Dr Warrell.
The world woke up to the seriousness of the neglected issue of snakebite deaths when the Million Death Study (MDS) of 2011 and 2020 provided, for the first time, reliable, nation-wide estimates of deaths due to snakebites in India. “The numbers were 20 times higher than official government figures and were largely responsible for changing the world’s opinion on the importance of snakebite,” says Dr Warrell. The researchers used data from these two studies to understand the trends in snakebite-related mortality in India in the last two decades.
Prevention may be much better than cure
Death due to snakebites is preventable with on-time access to antivenom post the bite. In India, only two-thirds of the victims get the required treatment within six hours of the bite. The researchers suggest improving the healthcare infrastructure to treat victims as soon as possible. Creating awareness about the dangers of snakebites also goes a long way in preventing deaths.
“The government should allocate resources to the worst-affected regions to improve community education, access to medical care, training of medical staff, and provision of appropriately designed antivenoms,” says Dr Warrell. “The government should improve ambulance services in rural areas, including motorbike ambulances where there are no roads and train the paramedics to help the victim until they reach the hospital.”
In India, people often resort to seeking traditional medicine for snakebites and thus delay getting care. Community education, the researchers say, could help in encouraging people to seek urgent hospital care if they are bitten.
Interestingly, snakebites are not all the same! Different species have different venoms that attack specific organs and systems in the victims’ bodies. The constituent of the venom also varies based on geography. A previous study has shown that the antivenom stocked in hospitals in India do not work on many snake venoms that are common in India. As a result, specific antivenoms, that are proven to be safe and effective against different species of snakes, are necessary to avert these deaths.
Preventing a snakebite, however, is not too difficult.
“Using a light when walking at night, sleeping on a cot or bed under a well tucked-in mosquito net, using footwear and staying vigilant when walking and working in the field, will help avoid snakebites,” says Dr Whitaker. When a venomous snake is spotted, it is best to alert authorised snake rescuers to safely rescue and translocate it away from human dwellings. “The contact details of these rescuers should be made available to everyone,” he suggests.