A parasite that puts up a fight: Managing Guinea worm disease

By Jules Murtha | Medically reviewed by Kristen Fuller, MD
Published May 3, 2023

Key Takeaways

  • Guinea worm disease (GWD), or dracunculiasis, is an illness caused by a parasitic nematode known as Dracunculus medinensis. GWD is most prevalent in African countries and poorer regions of the world.

  • According to the CDC, there is no current vaccine or medication to treat GWD. Patients manage the disease by removing the entirety of the worm after it ruptures the skin and emerges, and then care for the skin wound.

  • The Carter Center states that only 13 cases of GWD were reported worldwide in 2022—a monumental decrease in cases since the estimated 3.5 million reported in 1986. HCPs can aid in continuing this positive trend with diligent surveillance. 

In 1986, an overwhelming 3.5 million people across the globe were infected with Guinea worm disease (GWD). Caused by the parasite Dracunculus medinensis, GWD results in painful blisters on the lower extremities, from which a 2- to 3-foot worm eventually emerges.[]

Despite a setback in 2016, efforts to prevent the spread of GWD have been largely successful. Healthcare professionals and affected communities can aid in the eradication of GWD by diligent surveillance and containing cases as they pop up.

The cycle of Guinea worm disease

How did so many people come to be infected with GWD in the 1980s?

According to an article published by StatPearls, widespread infection begins with contaminated drinking water.[]

In low-income and rural areas around the world—especially in African countries, like Chad, Mali, Sudan, and Ethiopia—people often ingest water containing the intermediate host of the parasite, known as Cyclops, which harbors the larvae of D. medinensis.

Once ingested, the larvae penetrate the mucosa of the stomach and intestinal wall. The larvae mature into adult worms over the next 9 to 14 months, reaching about a meter in length. 

The worms migrate through the subcutaneous tissue, eventually heading for the surface of the skin, where they cause the painful blisters. When the worm breaks the skin, it emerges. The worms usually emerge on the feet.

Seeking relief from the painful blisters, infected individuals often submerged their feet into drinking water sources. This practice contributed to GWD becoming endemic to certain parts of the world, as the mature worms were able to disperse their larvae, contaminating the drinking water and perpetuating the cycle.

A surviving parasite

GWD was, at one point, a major global health concern, but cases have fallen dramatically over the years, largely thanks to the efforts of health officials and affected communities.

Despite this progress, Guinea worms have proven to be quite resilient.

In 2016, as reported in an article published by StatNews.com, health experts believed that the eradication of GWD was well within reach—until they discovered that the parasite was infecting canines, too.[] This discovery pushed the eradication date at least 5 to 10 years past originally anticipated.

In 2022, however, GWD cases reached the “lowest annual case total ever reported,” according to the Carter Center—only 13 human cases worldwide.[] 

And the implementation of effective case management and containment methods is a big reason why.[]

GWD treatment protocol and case management

According to the CDC, there aren’t any current medications designed specifically to treat GWD (nor is there a vaccine to prevent it).[] Instead, patients with GWD can take several steps to effectively manage their case:

  1. Refrain from making contact with drinking water sources in order to avoid spreading the parasite.

  2. Once the blister is identified, clean the wound. To encourage the worm to emerge and release larvae, the affected body part may be soaked in water (separate from the source of the community’s drinking water).

  3. As the worm begins to emerge, wrap it in gauze and gently pull it out, making sure not to break the worm. This process may take anywhere from days to weeks, depending on the length of the worm. Afterwards, apply topical antibiotics to the wound to prevent secondary bacterial infections.

  4. Wrap the affected site with fresh gauze to protect the skin. Take ibuprofen or aspirin to reduce pain and ease inflammation.

Road to eradication

Although health officials and community efforts have made great strides in the past several decades in bringing GWD under control, what will it take to eradicate it?

Eradicating a disease is a huge undertaking.

According to the Carter Center, just one human disease has been successfully eradicated: smallpox, in 1980.

The final handful of cases of a dying disease are usually the most difficult to manage, requiring persistence and an abundance of resources, in areas that are often remote.

But the CDC has faith that perseverance can be effective. Prevention is key, by continuing to identify and contain cases, and restrict persons already infected with GWD from contaminating the drinking water.

The road to eradication also requires the provision of safe drinking water.

Vector control is necessary, in order to kill the copepods associated with the Guinea worm life cycle and thus prevent the parasite from infecting humans and animals.

Finally, health education and community mobilization needs to continue. 

What this means for you

GWD is historically endemic to low-income, rural parts of the world, especially African countries like Chad, South Sudan, Ethiopia, and Mali. A global concern only a few decades ago, cases in humans have fallen dramatically, despite the absence of a vaccine and any form of medicinal treatment for the disease. This achievement is the result of concerted efforts to rectify the causative conditions. In order to prevent future cases, HCPs in affected areas can practice surveillance and case containment. Safe drinking water, vector control, health education, and community mobilization are also crucial to the eradication of GWD.

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