Snakebite kills 58,000 persons per year in India—study

NEW DELHI — A new study by the Center for Global Health Research (CGHR) at the University of Toronto, Canada, with Indian and UK partners reports a staggering 1.2 million snakebite deaths in India over a 20 years period from 2000-2019, an average of 58,000 deaths per year.

Published in eLife journal on 7 July, 2020, the nationally representative mortality study on snakebite deaths in India from 2000-2019 holds that the number of snakebite deaths over the past two decades far exceeds previous estimates.

(The Million Death study (MDS) published in 2011 had estimated 46000 snakebite deaths annually)

The new study expands the results of the 2011 study by adding 11 more years of field data from the MDS covering 600,000 randomly selected deaths, and a systematic review of 78 Indian snakebite studies.

It reports that 70% of these deaths occurred in limited low altitude, rural areas of eight states – Bihar, Jharkhand, Madhya Pradesh, Odisha, Uttar Pradesh, Andhra Pradesh (including Telangana), Rajasthan and Gujarat. In these high-burden states, the age-standardized death rate was about six per 100,000.

Snakebite death rates generally rose over time in most high-burden states, particularly in Bihar, but fell in Andhra Pradesh.

The study points that half of all deaths occurred during the monsoon period from June to September.

“The available data indicated that most envenomations were due to Russell’s vipers (43.2 percent) followed by kraits (17.7 percent) and cobras (11.7 percent),” the study revealed.

Of the 1.2 million snakebite deaths in two decades, 602,000 occurred among males and 5,65,000 among females. With both sexes combined, 28 percent deaths due to snakebite were among children below 15 years, 17 per cent among adults aged 15-29 years, while 47 percent of the deaths occurred in the age group of 30-69 years.

Senior author Professor Prabhat Jha, Director of CGHR at Unity Health Toronto said the study directly quantified and identified the populations most affected by fatal snakebites in India.

Bites by venomous snakes are acute medical emergencies, killing by shock, paralysis, hemorrhage or acute kidney injury, and injuring by inflicting gangrene. However, the risk of bites can be reduced through community education, while most deaths and serious consequences are preventable by timely access to safe and effective antivenoms.

The study recommends that the Government of India designate and enforce snakebite as a ‘Notifiable Disease’ within the Integrated Disease Surveillance Program (IDSP).

“The GoI’s official declaration of snakebite deaths in public hospitals during the period 2003 to 2015 was only 15,500, one tenth of the 154,000 snakebite deaths detected during this same period by MDS from public and private hospitals. We have to have accurate data for strategies to reduce snakebite.”

Another author, Romulus Whitaker (Padma Shree awardee) at the Center for Herpetology/Madras Crocodile Bank said since snakebite deaths are restricted mainly to lower altitude, intensely agricultural areas, during a single season of each year, this should make the annual epidemics easier to manage. “India’s tremendous snakebite burden is staring us in the face and we need to act now.”

The study said targeting certain areas with education about simple methods, such as ‘snake-safe’ harvest practices, wearing rubber boots and gloves and using rechargeable torches (or mobile phone flashlights), could reduce the risk of snakebites. Mass distribution of mosquito nets (which also protect against scorpion sting and mosquito-borne and sand fly-borne diseases) may also help.

It calls for improved knowledge of the distribution of venomous snake species as well as the human consequences of bites. The current Indian antivenoms neutralize venom from only spectacled cobra (there are three other Indian cobra species), common krait (there are seven other krait species), Russell’s viper and saw-scaled viper. At least 12 other species that are not covered by current antivenoms are known to have caused fatal bites in India.

“Achieving this will however be a challenge for India, where half of the world’s total snakebite deaths occur,” said author Professor David Warrell, one of the world’s leading figures in tropical medicine in the UK.