Guinea Worm Disease and Water Quality: How They’re Connected

What Is Guinea Worm Disease?

Guinea worm disease, or dracunculiasis, is a parasitic infection that occurs when the Guinea worm (Dracunculus medinensis) enters the human body through contaminated drinking water. The Guinea worm larvae grow inside the body, often without symptoms, and mate in the abdomen before migrating to the lower limbs or feet.

The adult female worm causes a painful blister before slowly emerging from the body. Because the emerging worm can grow up to three feet long, this process can last for weeks and cause severe pain and a secondary infection.

Humans have been dealing with Guinea worm disease for thousands of years. Since there’s no cure or vaccine, the main intervention is to manage the pain and remove the worm gradually. By ensuring access to filtered drinking water in affected countries, we can disrupt the Guinea worm’s life cycle and eradicate it altogether.

How Is Guinea Worm Disease Transmitted?

Guinea worm disease isn’t transmitted directly from person to person. It’s transmitted through contaminated water sources that contain copepods, a type of crustacean that hosts Guinea worm larvae. Once the copepods are ingested from drinking water, the larvae emerge through the stomach and intestines and into the abdomen.

Because the adult worm often emerges back into the same water system or a nearby one, it releases new larvae which are ingested and spread by copepods again.

Humans aren’t the only species affected by Guinea worm disease: animals, including dogs, can ingest Guinea worm larvae and spread the parasite to new hosts. Guinea worm disease can also be spread through food, such as eating undercooked fish or frogs that have ingested copepods or Guinea worm larvae.

What Regions are Affected by Guinea Worm Disease?

Guinea worm disease is considered a neglected tropical disease, which the World Health Organization (WHO) describes as “a diverse group of conditions caused by a variety of pathogens (including viruses, bacteria, parasites, fungi and toxins) and associated with devastating health, social and economic consequences.”

Guinea worm disease was once found throughout West and Central Africa, as well as parts of Asia, such as India and Pakistan. As recently as 1989, there were more than 892,000 reported cases of Guinea worm disease in these endemic areas.

According to the Carter Center, a non-governmental organization founded by former U.S. President Jimmy Carter, there were only 13 human cases in 2022 — primarily in endemic countries like Chad, South Sudan, and Ethiopia. Additional cases in animals were reported in Chad, Mali, Cameroon, Angola, Ethiopia, and South Sudan.

Guinea worm infections are primarily found in rural areas without access to filtered drinking water, which is why the Guinea Worm Eradication Program is focused on health education and ensuring access to clean drinking water sources.

How Does Contaminated Water Contribute to the Spread of Guinea Worm Disease?

Contaminated surface water sources are the main driver behind Guinea worm disease, because they harbor the copepods, or water fleas, that transmit the disease to humans. Both the human and copepod hosts play a key part in the incubation of the larvae and the ongoing spread of the disease.

Unfortunately, the nature of the disease perpetuates the cycle because infected people are likely to soak their painful blisters in water, often releasing the adult worm back into the water system. Guinea worm larvae are most likely to proliferate in stagnant water, which is unsafe for drinking, cooking, bathing, and even watering crops.

According to the Centers for Disease Control and Prevention (CDC), rates of infection vary depending on the time of year: “In dry regions, people generally get infected during the rainy season… In wet regions, people generally get infected during the dry season,” because this is when surface water sources are most likely to be stagnant.

Fortunately, cloth filters are incredibly effective at removing copepods, and eradication efforts that focus on filtration have been remarkably successful. Some countries, such as Ghana, have managed to eliminate Guinea worm transmission entirely.

What Measures Are Being Taken to Control Guinea Worm Disease?

The International Commission for the Certification of Dracunculiasis Eradication is in charge of verifying the eradication of Guinea worm disease in any given country. But what measures are being taken to control the disease globally? Here are the three primary components of Guinea worm disease eradication campaigns.

Water filtration

The centerpiece of Guinea worm disease eradication is water filtration. Even pipe filters — a type of drinking straw with a mesh filter — are effective at preventing the ingestion of copepods from contaminated water. In fact, that’s the origin of the LifeStraw, which played a key role in eradication efforts in the 1980s.

At the community level, campaigns can focus on strategies such as installing deeper wells that are less likely to be contaminated, and improving water storage systems.

Health education

Health education also goes a long way toward reducing the spread of Guinea worm disease. Global health workers can emphasize the importance of keeping infected people out of surface water sources so as to prevent further contamination.

Health care interventions, such as disinfecting wounds and bandaging the area effectively, can reduce secondary infections and other side effects.

Containment

Finally, detecting new cases and containing them can help to eradicate Guinea worm disease from the remaining African countries where it’s endemic. Surveillance teams work to identify the origin of the infection, while containment centers provide care for infected people while they recover.

Health workers can also use larvicide such as temephos to kill copepods in stagnant water sources that are known to be contaminated with Guinea worm larvae.

What Are the Remaining Challenges In Eradicating Guinea Worm Disease Worldwide?

Guinea worm disease would be the second infectious disease ever to be eradicated in humans — and the first parasitic disease — after smallpox. The eradication of Guinea worm disease is in sight, but there are still a few challenges facing healthcare workers and NGOs working on eradication, such as:

• Monitoring: Because of the long incubation period, it can take years to confirm that the disease has actually been eliminated from a given region.
• Violence: Ongoing conflict in some regions can make it difficult for health care workers to gain access to the communities they need to reach.
• Animal transmission: Dogs are becoming a vector for transmission in some countries due to their ingestion of infected fish.

Illiteracy can also be an obstacle to effective outreach and education. According to the American Museum of Natural History, “Because many people can’t read, workers get the message out in creative ways — through T-shirts, picture books, performances, radio broadcasts and visits from national leaders.”

What Organizations Are Actively Working to Eradicate Guinea Worm Disease?

Although Guinea worm disease is considered a neglected tropical disease, there are several organizations working to eliminate it. Here are just a few examples:

• The Guinea Worm Eradication Program (GWEP) is an international initiative primarily made up of village volunteers who undertake surveillance, case containment, and health education for their communities.
• UNICEF, or the United Nations Children’s Fund, focuses on providing resources and humanitarian aid, including access to clean water sources.
• The U.S. Centers for Disease Control and Prevention assists with epidemiology and the identification and tracking of Guinea worm disease cases.
• The World Health Organization oversees the certification of countries as Guinea worm-free through an independent certification commission.
• The Carter Center provides financial support to local organizations working to eradicate the Guinea worm, and keeps track of annual case numbers.

How Can Communities Protect Themselves From Guinea Worm Disease Through Better Water Management?

In most parts of the world, Guinea worm disease isn’t a major concern, although other waterborne diseases, such as cholera and typhoid, may be present. If you do live in a region where Guinea worm disease remains a risk, you can protect yourself and your community in the following ways:

• Filter water used for drinking and cooking: Since copepods and Guinea worm larvae can’t easily be seen without a magnifying glass, assume all surface water needs to be treated. Hand-dug wells are safer than stagnant water sources.
• Avoid re-contaminating water sources: Anyone who has a blister or emerging worm should stay away from any water sources that are used for drinking.
• Treat affected water with larvicide: Communities can break the transmission cycle by using temephos or other larvicides to treat contaminated water.