Understanding the Relationship Between Livestock, Snakes and Livelihoods in Costa Rica

By Andrea Nickerson, IGHS master’s student

UCSF Institute for Global Health Sciences master's student standing near a white cow in Costa Rica
Andrea Nickerson in Costa Rica

When I joined the Institute for Global Health Sciences master’s class of 2018 last August, I never thought I would end up working on a project centered around snakebite. During my search for a capstone research topic, my interest in One Health—the concept that human, animal and environmental health are inextricably linked—guided me to the idea of researching how snakebite envenomation in livestock impacts farmer’s lives.

If you are thinking, “Is that even a real problem?” you are not alone. Since choosing my topic and sharing my idea, I’ve received many looks of confusion and slow questioning nods from my family and friends because they, like me, had no idea that snakebite envenomation—the injection of venom into a human or animal through the bite of a venomous snake—was a major health threat.

Snakebite envenomation, however, is a serious global health issue. In 2017, it was added to the World Health Organization (WHO) list of Neglected Tropical Diseases, and University of Oxford Professor David Warrell describes it as “the most neglected of all the so-called neglected tropical diseases” in the new snakebite documentary, Minutes to Die. According to the WHO, each year throughout Sub-Saharan Africa, Southeast Asia, and Central and South America, snakebite envenomation will cause more than 400,000 permanent disabilities and over 125,000 human deaths, making snakes the third deadliest animal on the planet.

While global health workers might consider snakebite envenomation as a direct human health threat to be the road less traveled, the impact of snakebite envenomation in livestock doesn’t even have a path. My capstone required me to machete my own road. The literature surrounding the impacts of snakebite in livestock and how these impacts contribute to the overall burden of snakebite envenomation is all but non-existent. I struggled to find the smallest mentions of livestock in published studies, much less something meaningful such as bite incidence rates or economic effects. There were many days when I doubted whether my project would yield something meaningful. Why had no one studied this? Did this issue actually exist? What ultimately kept me afloat was the enthusiasm and stories I heard from others in the snakebite community and the support I received from my mentors, Dr. Matt Lewin and Ms. María Herrera Vega.

Now, however, four weeks into data collection in Costa Rica, I can confidently say that venomous snakes do pose a threat to livestock health and farmer livelihoods here. The farmers we have spoken to have told countless, heart-wrenching stories of waking up to find livestock killed by snakebite or suffering the severe effects of envenomation. Animals found alive frequently can’t be saved because the farmers are unable to appropriately treat them, and so they lose animals that may be their only source of income or savings.

Antivenom is the only scientifically validated method for treating snakebite envenomation, and despite many farmers possessing it, the medicine can be used only when an animal is found alive. Unfortunately, time and time again, farmers find their animals already dead. These farmers can do virtually nothing to prevent snakebite except kill the snakes, both venomous and non-venomous (they say serpiente buena, serpiente muerta, “a good snake is a dead snake”), that they find on their farms, which disrupts local ecosystems. However, if an animal is found in time, farmers attempt to treat it. The treatment is difficult to administer properly, and antivenom is not an option for everyone due to its price and lack of availability.

These issues force farmers to turn to unvalidated treatments such as canfín con agua (kerosene with water), bleach, a variety of plant drinks and unknown concoctions provided by local “healers.”

The loss of livestock animals affects the farmers economically and emotionally. One farmer was finally going to be able to afford to install electricity and running water in her home, until all six of her calves were found dead from snakebite. Another farmer went a month without milk because it was unsafe to drink after administration of antivenom and antibiotics to the cow. Many farmers are left feeling impotent because they have no chance to save the animals they love and depend on. The deaths and injuries caused by snakebite in both humans and animals make some farmers feel unsafe on their farms and in their own homes.

This study is only the first step to understanding the full impact of snakebite envenomation in livestock on farmer’s lives. I am grateful for the opportunity to share these farmers’ stories, and hopefully help bring some relief to the people and animals who bear the burden of this neglected tropical disease.

To learn more about snakebite and its impacts, check out these resources:

Snakebite Healing and Education Society

Minutes to Die

WHO Snakebite Envenoming