Vietnam has suddenly reported over 20 patients infected with the Guinea worm – a dangerous disease that is typically found only in Africa, and currently has no specific treatment.
Important Facts About Guinea Worm Disease
What is Guinea worm? Is the disease dangerous? What are the causes and treatment options? Follow the article below for detailed information about this disease.
What is Guinea Worm?
Guinea worm or Dracunculus medinensis is the scientific name for this organism. It is the longest roundworm among the group that can cause parasitic infections in humans. The adult female Guinea worm has a diameter of 1-2 mm and a length of about 70-120 cm, while the male worm is shorter, measuring around 4 cm. The male Guinea worm dies after mating. (1)
Life Cycle of the Guinea Worm
The Guinea worm has been mentioned since ancient Egypt in the early 15th century BC. Today, the disease has been recorded in countries such as India, Cameroon, Mauritania, Uganda, South Sudan, Saudi Arabia, Iran, Yemen, Ethiopia, and Mali. Guinea worm disease instills fear in many when they see the parasitic creature emerging from beneath the skin, causing severe damage and pain.
In 1986, the World Health Organization launched a campaign to eradicate parasites, including the Guinea worm. This campaign showed promising results, with only 22 cases reported in 2015 across four countries (Ethiopia, Chad, Mali, and South Sudan). Vietnam has previously recorded four cases. In 2022, a 42-year-old man from Yen Bai pulled out an 8 cm long Guinea worm from a ruptured abscess. (2)
Patients often have a habit of drinking from streams and eating raw fish. Recently, another patient was admitted with breathing difficulties, swelling in the chest, left arm, and left thigh, along with painful and pus-filled areas.
Causes of Guinea Worm Disease
Each female Guinea worm can carry up to 3 million larvae. In the external environment, the larvae can survive for up to three weeks. Guinea worm larvae become food for crustaceans called Cyclops (water fleas), but they can live and remain viable for up to four months after being ingested by these crustaceans. This makes the spread of the larvae that cause the disease in humans and animals easier and faster.
Guinea worms primarily enter the bodies of humans and animals through contaminated water sources or through the digestive tract when consuming food contaminated with Cyclops infected with the larvae. Specifically, aquatic species that eat water fleas become infected with the larvae, which then continue to parasitize fish, shrimp, crabs, frogs, etc.
Humans and animals (dogs, cats, etc.) that consume raw or undercooked aquatic products are at risk of being infected with Guinea worm larvae. Additionally, individuals can become infected by drinking water containing the carcasses of infected water fleas. Potential sources of Guinea worm larvae include water from rivers, streams, ponds, and lakes. The disease can affect individuals of all ages, with infection rates reaching up to 60%.
Once a person ingests infected water fleas, the stomach acid kills the fleas, causing their bodies to break down and release Guinea worm larvae. The larvae attach to the stomach and take about ten weeks to develop into worms. The worms penetrate through the stomach wall and small intestine to enter the abdominal cavity. After mating, the male dies, and the female matures, eventually emerging through the skin of the host to cause clinical symptoms.
The time it takes for the larvae to develop into worms and emerge through the host’s skin ranges from 9 to 14 months, with almost no symptoms until the worms push through the skin. The head of the female Guinea worm reaches the epidermis, causing blisters that will rupture upon contact with water, leading to ulcers. After 2-3 weeks, when the ulcer comes into contact with water, the worm releases larvae into the environment. Some mature worms will emerge, while others may burrow deeper into the body, leading to death and severe inflammatory reactions.
The disease is not directly fatal but can cause indirect fatalities due to complications such as secondary infections, cold abscesses, septic arthritis, spinal cord paralysis, and hemiplegia.
Water fleas ingesting Guinea worm larvae.
Guinea worm disease does not have a seasonal pattern and can occur year-round. The period of increased cases varies by location. In arid regions, infections typically occur during the rainy season, while in areas with abundant rainfall, infections are more common during the dry season. The risk of infection does not discriminate by age or gender; however, statistics show that most cases are in individuals aged 15 to 45 years, particularly those working in agriculture. Therefore, individuals engaged in livestock farming, aquaculture, and crop cultivation are at a higher risk due to their frequent exposure to water sources containing Guinea worm larvae.
Adult Guinea worm emerging through the skin.
Symptoms of Guinea Worm Disease
After ingesting Guinea worm larvae, they are released in the stomach, develop into worms, and penetrate the stomach lining, subsequently moving into connective tissue beneath the skin, often in the leg area. The incubation period is about 9 to 14 months, during which the mature female can reach up to 1 meter in length. Before surfacing through the skin, the female worm creates a painful and itchy blister. If this blister ruptures and comes into contact with water, it allows the Guinea worm to release its larvae into the environment.
Initially, after being infected with the larvae, patients will not exhibit symptoms in the first year. Symptoms typically arise when the female worm begins to emerge through the skin and damage the tissues. As the worm starts to surface, the patient may experience symptoms such as:
- Blisters and swelling on the skin with diameters of 2-7 cm.
- Severe tingling and itching.
- Pain and burning sensations at the affected site.
- Hives and rashes.
- Mild fever.
- Diarrhea.
- Breathing difficulties, dizziness, vomiting.
- Severe dermatitis.
During the egg-laying process, the worm may release toxins that cause severe ulcers and intense pain. When the swelling ruptures and releases yellow fluid, the worm will begin to emerge. If no intervention occurs, the worm will completely exit the body within 3-6 weeks, although some female worms may burrow back in deeper.
Along the path the female Guinea worm travels, it can cause secondary infections leading to sepsis. When secondary infections occur, the patient will exhibit symptoms related to inflammation and joint pain. If not treated promptly, the patient may face joint stiffness and ligament contractions.
Diagnosis Methods
Diagnosis of the disease typically relies on clinical symptoms such as visible adult Guinea worms emerging through the skin or the head of the female worm appearing at the ulcer site. X-rays may be taken to detect calcified worms in the host’s body. Blood tests or examination of fluid from the wounds can also be conducted for diagnosis. If there is an increase in eosinophils in the blood and larvae are found in the wound fluid, the patient is diagnosed with Guinea worm disease.
Complications if Guinea Worm Disease is Not Treated Promptly
If Guinea worm disease presents clinical symptoms and is not treated quickly, it can lead to dangerous complications such as cellulitis, abscesses, septicemia, tetanus, septic arthritis, and joint deformities.
As of now, the mortality rate from Guinea worm disease is very low, but its complications can significantly affect the patient’s quality of life. Patients may become permanently disabled due to superinfection. Guinea worm disease also impacts the socio-economic status and health of the community due to its complications.
Currently, there is no vaccine or treatment for Guinea worm disease, only symptomatic treatment is available.
Treatment Options
Currently, there is no vaccine or specific medication for Guinea worm disease, and treatment is limited to symptom management. Therefore, early detection and treatment can reduce the risk of dangerous complications.
- Wound Hygiene and Water Soaking: Upon discovering an infection with the Guinea worm, patients should limit contact with water sources. Clean the wound thoroughly and soak it in warm water to encourage the worm to release all larvae, making it easier to remove. The soaking water should be treated with chemicals or boiled to kill any larvae present.
- Treating the Wound with Antibiotics: Patients need to rest in bed, keep the ulcer clean, and apply topical antibiotics to prevent secondary infections.
- Manual Extraction of the Worm: This is a traditional method of pulling the worm out using a small wooden stick. Once the worm has released all larvae, it tends to emerge. Wrap the worm’s head around the stick and gradually pull it out a few centimeters each day. Combining this method with anti-worm medication and wound sterilization facilitates the worm’s removal. It is advisable to visit a medical facility for the extraction, as mishandling could lead to the worm breaking and potentially causing secondary infections, leading to sepsis or abscesses.
- Taking Anti-Worm Medication: Medications such as metronidazole and thiabendazole can alleviate symptoms and help the worm to emerge or expedite the manual extraction process. These medications can help reduce inflammation but cannot kill the larvae or adult Guinea worms.
- Surgical Removal of the Worm: When the worm is parasitic under the skin, surgery can be performed to remove it. Surgery is only possible if the worm is not entangled in deep fascia or around tendons.
Preventing Dracunculus medinensis Infection
The World Health Organization has launched a campaign to eradicate Guinea worms, and significant progress has been made towards elimination. However, Guinea worm larvae can parasitize various hosts, including dogs, cats, and aquatic species, making infection control challenging. Alarmingly, in recent years, Vietnam has reported some cases of the disease.
The disease is asymptomatic during the first year of incubation, making detection and treatment difficult. Therefore, proactive prevention is essential through the following measures:
- Eat Cooked Food and Drink Boiled Water: Guinea worms and their larvae can be killed by exposure to temperatures above 100°C. Foods, especially seafood, should be thoroughly cooked. Clean the intestines of fish, frogs, shrimp, etc., before cooking. Raw vegetables grown in water should be blanched in boiling water before consumption or washed under clean, strong running water.
- Drink Boiled Water or Filtered Water: Always boil drinking water or use water filtered through a machine.
- Only Use Clean Water Sources: If clean water sources are unavailable, residents should employ water treatment methods such as using water filtration devices or insecticides to eliminate water fleas.
Do not feed dogs and cats fish, frogs, or seafood unless it is fully cooked. - Patients with Guinea Worm Infection Should Cover Their Wounds: Keep wounds tightly bandaged and avoid contact with community clean water sources to prevent the female worm from releasing eggs into the water, thus infecting others.
- If dogs or cats exhibit symptoms such as blisters, swelling, or visible worms in wounds, avoid contact with community clean water sources.
In recent years, Vietnam has reported several cases of Dracunculus worm disease in both humans and animals. Although the risk of death from the disease is low, complications caused by Guinea worms can pose serious health risks, significantly impacting patient health.
