The World Health Organization (WHO) has updated its fact sheet on snake envenoming recently.

Key Messages:

Though the exact number of snake bites is unknown, an estimated 5.4 million people are bitten each year with up to 2.7 million envenomings (poisoning from snake bites).

Around 81 000 to 138 000 people die each year because of snake bites, and around three times as many amputations and other permanent disabilities are caused by snakebites annually.

Agricultural workers and children are the most affected. Children often suffer more severe effects than adults, due to their smaller body mass.

In Asia up to 2 million people are envenomed by snakes each year, while in Africa there are an estimated 435 000 to 580 000 snake bites annually that need treatment. Envenoming affects women, children and farmers in poor rural communities in low- and middle-income countries.

Bites by venomous snakes can cause

• paralysis that may prevent breathing,
• bleeding disorders that can lead to a fatal haemorrhage, irreversible kidney failure and
• tissue damage that can cause permanent disability and limb amputation.

Most deaths and serious consequences from snake bites are entirely preventable by making safe and effective antivenoms more widely available and accessible. High quality snake antivenoms are the only effective treatment to prevent or reverse most of the venomous effects of snake bites. They are included in the WHO List of essential medicines and should be part of any primary health care package where snake bites occur.

A significant challenge in manufacturing of antivenoms is the preparation of the correct immunogens (snake venoms). At present very few countries have capacity to produce snake venoms of adequate quality for antivenom manufacture, and many manufacturers rely on common commercial sources.

Health systems in many countries where snake bites are common often lack the infrastructure and resources to collect robust statistical data on the problem.

Under-reporting of snake bite incidence and mortality is common. In situations where data on snakebite envenoming is poor, it is difficult to accurately determine the need for antivenoms. This leads to under-estimation of antivenom needs by national health authorities driving down demand for manufacturers to produce antivenom products, and for some, their departure from the market. Weak regulatory systems in countries that lack expertise in antivenom evaluation can contribute to inappropriate procurement of ineffective or incorrect products. Inefficient distribution strategies can hinder access to antivenoms and create shortages of supply.

Given low demand, several manufacturers have ceased production, and the price of some antivenom products have dramatically increased in the last 20 years, making treatment unaffordable for the majority of those who need it. Rising prices also further suppress demand, to the extent that antivenom availability has declined significantly or even disappeared in some areas. The entry into some markets of inappropriate, untested, or even fake antivenom products has also undermined confidence in antivenom therapy generally.

Many believe that unless strong and decisive action is taken quickly, antivenom supply failure is imminent in Africa and in some countries in Asia.

Following a request by several UN member states, WHO formally listed snakebite envenoming as a highest priority neglected tropical disease in June 2017.

A Snakebite Envenoming Working Group was established in 2017 and tasked with informing the development of a strategic WHO road map on snakebites. This strategy focuses on a 50% reduction in mortality and disability caused by snakebite envenoming by 2030. This aim will be achieved through four key objectives:

• Empower and engage communities,
• Ensure safe, effective treatment,
• Strengthen health systems, and
• Increase partnerships, coordination and resources.

The full strategy will be launched in May 2019 with copies of the road map  available on the WHO website after the launch.

Useful Links:

Link to the updated fact sheet:

https://www.who.int/news-room/fact-sheets/detail/snakebite-envenoming

Link to Frequently Asked Questions on snake bites:

https://www.who.int/snakebites/snakebites_FAQ/en/

Link to WHO page on snakebites:

https://www.who.int/snakebites/en/

Link to WHO’s photo gallery of the 12 snakes most involved in envenoming in the world:

https://www.who.int/snakebites/resources/photo_gallery_snakes/en/