Feature Neglected diseases

Snakebite: a forgotten problem

BMJ 2013; 346 doi: http://dx.doi.org/10.1136/bmj.f628 (Published 31 January 2013) Cite this as: BMJ 2013;346:f628
  1. Soumyadeep Bhaumik, medical doctor, independent researcher, and freelance writer, Kolkata, India
  1. soumyadeepbhaumik@rediffmail.com

India has the worst snakebite problem in the world, largely affecting poor people and children from rural communities. This might explain why treatment and the training of doctors in India are lacking, explains Soumyadeep Bhaumik

When Alexander the Great invaded India in 327-325 BC he was said to be impressed by the arrow heads poisoned with lethal venom from the Russell viper and the advanced clinical acumen of Indian doctors in managing snakebite.1 In 2009 the World Health Organization added snakebite to its list of neglected tropical diseases, hoping to reduce its burden on so many marginalised populations.

“We need to act now to deal effectively with this problem, which causes severe disability, brings misery to families, and which kills thousands of people,” said Lorenzo Savioli, director of the department of control of neglected tropical diseases at WHO.2 However, policy makers, clinicians, and the general public have largely ignored the snakebite problem, even though it kills thousands of people each year and causes social, economic, and personal misery to many more.

Ghulam Nabi Azad, the union health and family welfare minister of the government of India, told the Lok Sabha, India’s lower house of parliament, in April 2012 that only 1440 people had died from snakebite in India in 2011.3 WHO, however, predicts as many as 1 841 000 envenomings and 94 000 deaths globally, with India having the most of any country, with an estimated 81 000 envenomings and 11 000 deaths a year.2 The Million Death Study4 estimated some 45 900 deaths from snakebite in India in 2005, about the same number as those from HIV/AIDS.5

Experienced doctors

“Worldwide, snakebite has been neglected and forgotten and its victims abandoned by medical science and public health systems,” said David A Warrell, emeritus professor of tropical medicine at the University of Oxford and one of the researchers involved in the Million Death Study. “This neglect is particularly surprising in India, which has long been regarded as the country that suffers the worst snakebite problem in the world but whose doctors have the greatest experience and skill in dealing with this ancient scourge of mankind.”

Government statistics don’t properly reflect this health problem’s fatal consequences, said Aditi Aikat, associate professor in community medicine, from North Bengal Medical College, West Bengal, India. The main cause of under-reporting is that people bitten by snakes often prefer to see ojhas, or traditional faith healers, rather than attend hospital because of their poor educational and economic backgrounds. Cultural beliefs play a big part in such customs; the bodies of people who have died from snakebite are often disposed of on rafts made from banana trees on the rivers in eastern India, particularly in the Sundarbans.

Canning Juktibadi Sanaskritik Sanastha, a non-governmental organisation in West Bengal, has been encouraging traditional faith healers to refer victims to health centres after snakebite.

“There is also a false notion among many that after all snakebite deaths there must be postmortem examination,” Dayal Bandhu Majumdar, who teaches about snakebite at the Institute of Health and Family Welfare, Government of West Bengal, told the BMJ. “Many relatives of snakebite victims try to hide the cause of death just to avoid postmortem examination.”

However, Ulrich Kuch, head of the emerging and neglected tropical diseases unit at Frankfurt’s Biodiversity and Climate Research Centre, Germany, thinks that under-reporting is “a symptom of lack of access to basic healthcare, lack of access to essential drugs, and lack of health education . . . Wherever there is access to effective allopathic treatment for snakebite envenoming at the primary healthcare level, the quacks are out of business. They tend to be quite expensive too and often charge more than the medical treatment would cost.”

Snake antivenoms

Snake antivenom can correct bleeding and clotting disorders, shock, and cobra bite paralysis, and early use can prevent life threatening envenoming and local tissue destruction. The efficacy of snake antivenom can vary, and without consensus on recommended dosage, there is controversy about the proper dose and protocol for administration. A prospective study from Chandigarh found “no difference between a protocol employing lower doses of SAV [snake antivenom] to higher dose in the management of patients with ‘unselected’ severe neurotoxic snake envenoming.”6 However, such studies have not been accepted by many doctors in India who advocate higher, traditional doses of antivenom.

Snake antivenoms are underused in India because of lack of availability and cost. The Indian polyvalent antivenom costs about $9-10 (400-538 rupees; £5.7-6.5; €6.6-7.4) per vial. Most snakebites require at least 10 vials, and the minimum $100 is not affordable for most ordinary Indians. However, some state governments in India provide antivenom for free in their hospitals, but even here the supply is irregular.

Where antivenom is available health workers can be afraid to treat snakebite victims, fearing adverse reactions. “The prime reason for this is inadequate training on the diagnosis and management of snakebite,” thinks Julian White, head of toxinology at the Women’s and Children’s Hospital, North Adelaide, Australia. Majumdar agrees and rues the fact that some doctors are less confident than faith healers about snakebite and do not treat patients with snake antivenom despite its being available for free at many government primary healthcare centres.

Indian antivenom has a reputation for causing adverse events. In Sri Lanka, where only antivenoms made in India were available, about 43% (n=20) had severe adverse reactions, with as many as 81% having early reactions.7 Early reactions occur during or soon after antivenom is administered. They are mostly allergic or anaphylactic, and are thought to be caused by complement activation.

“There are modern methods for making antivenoms that can reduce the likelihood of major adverse reactions to a low rate, but it does not appear these methods have been universally adopted by Indian antivenom producers. However, it may be that at least some producers are moving towards better production methods and a safer product,” explained White.

Many doctors advocate use of adrenaline. A randomised, double blind, placebo controlled trial from Sri Lanka found that prophylactic subcutaneous low dose adrenaline prevented adverse reactions to snake antivenom.8 The same study showed that promethazine and hydrocortisone are ineffective for this purpose. No such studies have been carried out in India.

“We have been employing it [snake antivenom] routinely in our hospital in Cochin and have not found major problems. Some cases do not respond probably because the antivenom is made from snakes in certain geographical areas that may exhibit species differences to other areas,” thinks V V Pillay, chief of the poison control centre and head of the department of analytical toxicology at the Amrita Institute of Medical Sciences and Research, Cochin, Kerala. Indian snake antivenoms are made from toxins derived from the four most common species: Russell’s viper, the saw scaled viper, the spectacled cobra, and the common krait. “They do not cover the venoms of any of the Indian pit vipers and may not be effective for bites by monocellate cobras (in the east), the Oxus cobra (in the north), several other species of krait, and the king cobra,” explained Warell.

“Within even a single species of snake, such as the common cobra or Russell’s viper, there can be marked geographic variation in venom activity. To make an effective antivenom, the immunising venom used must come from diverse geographic areas, to ensure venom variability is covered,” explained White.

Regulations in India about who can supply antivenom, and from where, might be making it difficult to provide geographically diverse venom for antivenom production. Most of the antivenom in India comes from one snake park in Tamil Nadu. As a result, the antivenom is not uniformly effective in all parts of the country, and the dose required differs.

Official neglect

WHO has published guidelines on production, control, and regulation of antivenom,9 which need to be implemented in India. “However the plan to provide expert technical advice for antivenom producers could not be funded,” said Warell.

Majumdar said that snakebite is “a deliberately neglected disease” in India, explaining that his own state of West Bengal has a deluge of officers appointed at all levels to take care of the problem of malaria but “not a single officer” to look after the problem of snakebite.

“Snakebite, as a subject for medical research, has suffered because, in comparison with other neglected tropical diseases, it is not an infectious disease, cannot be prevented by vaccination, and can never be eliminated. As a result, it has been overlooked by international charities and funding agencies,” added Warell.

The perception is that snakebite is an accident rather than a disease. But the key reason snakebite is not a priority is that most victims lack political voice because they tend to be poor, children, and from rural areas.4

“The global toxinology community remains concerned about the impact of toxin or venom based diseases on vulnerable populations, such as those in rural India, where we know from hard evidence that snakebite exerts a huge human toll,” White told the BMJ. The problem of snakebite, neglected at all levels, is not exclusive to India, contended Kuch, but he added, “India is definitely in a position where it could turn the tide for this neglected disease of poverty.” The Chinese year of the snake starts on 10 February, but will 2013 also be year of the snake in India?

Some ways in which India can raise its game

  • Make snakebite a notifiable disease

  • Raise awareness among the public as well as health professionals in rural areas

  • Develop an updated national snakebite management protocol that has broad consensus and national acceptability. (The National Snakebite Management Protocol 200710 did not have many takers)

  • Invest in research, including studies of species with greatest medical importance, community based studies of incidence of bites and resulting mortality and persisting morbidity. Research priorities and recommendations as identified by the South Asian Cochrane Network and Centre might be used as a reference10

  • Integrate snakebite management in doctors’ training as well as medical curriculum

  • Work towards a snakebite prevention programme where common habitats and habits are mapped. The local population should be appropriately advised, and protective boots, gloves, and trousers provided for high risk groups

  • Provide better access to healthcare facilities with better referral and effective transport to critical care facilities

Notes

Cite this as: BMJ 2013;346:f628

Footnotes

  • Competing interests: I have read and understood the BMJ Group policy on declaration of interests and declare that I am the country representative for the health information for all by 2015 (HIFA2015) campaign and knowledge network.

  • Commissioned; not externally peer reviewed.

References