In June this year, the WHO placed snakebite envenoming on its list of top-20 priority neglected tropical diseases. In this article, Dr Bharati contends that India, which has the highest burden of snakebite mortality in the world, should grab the opportunity to spearhead the global initiative to tackle the disease.

Snakebite is a neglected public health problem in several tropical and subtropical countries around the globe. It is probably the ‘most neglected’ of the neglected tropical diseases (NTD). In fact, it is so neglected that until very recently, it wasn’t even categorised as an NTD. Now, the World Health Organization (WHO) has recognised snakebite envenoming as a NTD, and has placed it on its list of top-20 priority NTDs (WHO, 2017). This has been possible largely due to lobbying by activists around the globe who have advocated hard for inclusion of snakebite envenoming within the ambit of NTDs.

The snakebite problem

The actual number of snakebites is difficult to ascertain. However, it is estimated that globally, approximately 5 million snakebites occur annually, with up to 2.5 million envenomings. At least 100,000 people die annually, while approximately 300,000 are maimed or permanently crippled, often requiring amputations (WHO, 2015). Importantly, these figures are hospital-based and therefore gross underestimations since most snakebite cases occur in remote rural areas, which often do not even reach the hospital (Groneberg et al. 2016).

Venomous snakebites can cause paralysis of the respiratory muscles that can hinder breathing; severe bleeding that can lead to fatal haemorrhages; irreversible kidney failure and tissue damage, causing permanent disability and the need for amputation of the affected limb. The most affected are agricultural workers and children, with the latter being especially vulnerable due to their smaller body mass.

The only effective treatment for snake envenomation is administration of snake antivenom. Indian snake antivenom is manufactured from a mixture of venoms from four snakes - “The Big Four” - which are responsible for the highest mortality and morbidity in India. These include the Indian cobra, Russell’s viper, saw-scaled viper, and the common krait.

The Indian scenario

India plays a prominent role in snakebite epidemiology due to the vast size of the country and a huge population, of which the majority (approximately 70%) resides in rural areas. A previous study had estimated annual snakebite mortality in India to be approximately 15,000 (Kasturiratne et al. 2008). However, a recent landmark study (Mohapatra et al. 2011) called the “Million Death Study” puts that figure to at least three-times higher. The study provides an estimation of direct snakebite mortality from a national mortality survey using data from 123,000 deaths from 6,671 randomly selected areas between the years 2001 and 2003. The study findings indicate that approximately 45,900 snakebite deaths occur annually in India, which is the highest in the world. Importantly, the majority of these deaths occur in rural areas, which account for 97% of all snakebite deaths in India. Most snakebite deaths occur in the states of Uttar Pradesh (8,700), Andhra Pradesh (5,200), and Bihar (4,500) on an annual basis (Mohapatra et al. 2011).

Since, most of the primary health centres in rural India have poor infrastructure and lack trained staff for tackling a snake envenomation emergency, many rural folk either turn to traditional healers or don’t seek care at all. This implies that the number of victims is probably much higher than officially reported. In view of this underestimation, snakebites need to be considered as a neglected problem in 21^st century India in particular and South Asia in general (Alirol et al. 2010, Warrell 2011).

What can be done?

With the inclusion of snake envenomation in the list of NTDs, this disease will receive the due attention that it previously lacked at the global platform of health policymakers. India should grab this golden opportunity to spearhead this global initiative.

WHO’s proactive role will fuel numerous efforts, including increased global funding for snakebite management. India should leverage funds for training of medical personnel, community mobilisation, advocacy regarding snakebite prevention and treatment, and provision of good quality snake antivenom.

At present, only a handful of Indian companies manufacture snake antivenom with a collective manufacturing capacity estimated to be around 1,958,000 vials (10 ml antivenom per vial) in 2011-2012 (Whitaker and Whitaker 2012). The government should provide incentives for capacity-building in these companies so that this essential life-saving medicine remains in adequate supply.

More public-private-partnerships (PPPs) and hand-holding among the various stakeholders should be facilitated in snake antivenom manufacture, testing, and quality control. Importantly, existing vaccine-producing companies or start-ups should be roped-in and encouraged to manufacture snake antivenom. These companies could be linked to government organisations like the Central Research Institute (Kasauli, Himachal Pradesh) in a PPP modality to increase production capacity.

On the research front, more funding should be encouraged through international collaborations as well as national funding agencies for developing new therapeutic molecules to treat cases of snake envenomation. Moreover, research should be directed at developing rapid diagnostic tests that could be used in low-resource settings.

Therefore, community participation, education of susceptible populations, imparting training to medical staff to tackle snakebite emergencies, and ensuring availability of snake antivenom, especially in the states with the highest burden of snakebite, could reduce the number of snakebite deaths in India. Importantly, the recently revised health expenditure, which is to be raised to 2.5% of GDP (gross domestic product), is a major policy shift and a step in the right direction. However, greater political will is required to make a real impact at the grassroots level where the most poor, deprived, and illiterate bear the brunt of the burden of snake envenomation in India.

Further Reading

• Alirol, Emilie, Sanjib Kumar Sharma, Himmatrao Saluba Bawaskar, Ulrich Kuch and François Chappuis (2010), “Snake bite in South Asia: a review”, PLoS Neglected Tropical Diseases, 4(1):e603. Available here.
• Groneberg, David A, Victoria Geier, Doris Klingelhöfer, Alexander Gerber, Ulrich Kuch and Beatrix Kloft (2016), “Snakebite envenoming – a combined density equalizing mapping and scientometric analysis of the publication history”, PLoS Neglected Tropical Diseases, 10(11):e0005046.
• Kasturiratne, Anuradhani, A Rajitha Wickremasinghe, Nilanthi de Silva, N Kithsiri Gunawardena, Arunasalam Pathmeswaran, Ranjan Premaratna, Lorenzo Savioli, David G Lalloo and H Janaka de Silva (2008), “The global burden of snakebite: a literature analysis and modelling based on regional estimates of envenoming and deaths”, PLoS Medicine, 5(11):e218.
• Mohapatra, Bijayeeni, David A Warrell, Wilson Suraweera, Prakash Bhatia, Neeraj Dhingra, Raju M Jotkar, Peter S Rodriguez, Kaushik Mishra, Romulus Whitaker and Prabhat Jha and for the Million Death Study Collaborators (2011), “Snakebite mortality in India: a nationally representative mortality survey”, PLoS Neglected Tropical Diseases, 5(4):e1018. Available here.
• The Hindu (2017), ‘Health spending to be 2.5% of GDP’, 17 March 2017.
• Warrell, David A (2011), “ Snake bite : a neglected problem in twenty-first century India”, National Medical Journal of India, 24:321-324.
• Whitaker, Romulus and Samir Whitaker (2012), “Venom, antivenom production and the medically important snakes of India”, Current Science, 103(6):635-643.
• World Health Organization (2015), ‘Snake antivenoms’, Fact Sheet No. 337, February 2015.
• World Health Organization (2017), ‘Neglected tropical diseases’, Programmes, 2017.