Dracunculiasis, also known as Guinea Worm disease (GWD), is a neglected tropical disease caused by the parasitic Guinea worm. Infection with the parasite occurs when a person drinks water containing water fleas infected with the larvae of the guinea worm.
Symptoms are not evident at first; however, the female worms begin to form a painful blister in the skin, typically on the lower limbs. Other signs that characterize the disease in this period include dizziness and vomiting.
The worm comes out of the skin after a couple of weeks, making it difficult for the person to perform everyday activities.
Dracunculus medinensis is the parasite responsible for causing the disease in humans. The worm is about 2 mm wide, with the adult females being longer than males at 60 – 100 mm ( the males are about 12 – 29 mm).
The guinea worm larvae can survive up to three weeks in the environment, during which they must be consumed by water fleas to continue their development.
Once inside the fleas, they can survive up to four months. The diagnosis of the disease is by examination of the suspected person for signs and symptoms.
Guinea worm disease can be prevented by keeping the person from putting the blister in drinking water to lessen the transmission of the parasite. Other methods of prevention include improved sanitation and proper access to clean, potable water.
Guinea worm disease affects mostly underdeveloped settlements in the remote parts of Africa with no access to safe drinking water. About 20 countries with the infection were reported in 1986, with most of the cases occurring in Africa.
Furthermore, 120 million people in Africa were at risk of the disease due to unsafe drinking water. The World Health Assembly (WHA) called for a formal resolution for the eradication of the disease in the affected countries.
As of 2019, there were 53 reported cases in four countries. This is in comparison with the 3.5 million cases in 1986. Guinea worm disease is thought to be the first parasitic disease that would likely be globally eradicated.
Causes and Risk Factors of Guinea worm disease
Infection by the parasite occurs when people drink stagnant water containing water flea. These fleas are too small to see with the naked eyes are carriers of these parasites.
The larvae of the guinea worm are swallowed by the water fleas inhabiting those stagnant water bodies and takes about three weeks to develop inside the water fleas before they can infect humans.
Stagnant and unsafe drinking water include those in pools, ponds, shallow wells, and drying water beds. The larvae of the guinea worm are usually absent in water from rivers and streams (flowing water).
Also, people living in countries where the disease is endemic like South Sudan and Chad, or those that consume raw or undercooked water animals might be at risk for guinea worm disease.
Changes in seasons also affect the transmission of the disease. People are at more risk of being infected during the rainy season in dry regions where stagnant water is available. People in wet areas are affected in the dry season when surface water starts to dry up and become stagnant.
Farmers, herders, and those that fetch household water are at risk of being infected with the disease. The parasite infects both men and women equally. Having the disease once does not confer life-long immunity to the infected person.
People suffering from guinea worm disease do so year after year. This may be due to having the same water source repeatedly contaminated.
Signs and Symptoms of Guinea Worm Disease
The disease does not often show any symptoms until about a year after infection. The infected person may develop a fever, pain, or swelling in the area a few days to hours before the parasite comes out of the skin.
The majority of the worms come out of the hands and feet, but they can appear in other parts of the body as well.
Since people in rural settlements with the disease do not often have access to good health care, removing the worm from the skin can be slow, painful, and disabling.
The sore caused by the parasite often gets contaminated with bacteria, which can make the pain more debilitating and increase recovery time. The infected person may not function for weeks or months.
Due to the burning sensation of the blisters, people usually soothe the pain by immersing the affected area (usually the lower limb) into water.
The worms in the infected person release thousands of larvae into the water. The disease becomes transmitted when people swallow the contaminated water. The fleas are killed in the stomach, but the larvae remain intact.
They penetrate the intestinal wall and migrate to the skin tissues where they form blisters and swell. The worm takes about a year to emerge after infection.
There is no medication or vaccine available to treat Guinea worm disease. Complications such as secondary bacterial infections like tetanus, amputations, or disability may arise if left untreated.
To reduce the pain from the emerging guinea worm, the infected limb would be submerged in a bucket of water. This would cause the worm to release its larvae and make it less infectious. The contaminated water is then discarded on the ground, far removed from any source of water.
The person would need to wrap the live worm on a stick to extract it. This process may take up to several weeks. Gently massaging the swollen area can help loosen the worm.
Removing the parasite may cause a burning sensation in the infected person. Surgery may be required if the patient is at risk of developing other complications.
Analgesics and painkillers can help reduce the pain, and antibiotic creams and ointments can prevent infections at the site of the wounds.
Prevention and Control
The disease can be prevented by avoiding drinking unsafe water. Following these simple control tactics can go a long way in the prevention of the spread of the disease:
- Drink water from protected sources (like boreholes) that are free from contamination.
- Prohibit people with swellings and wounds from entering ponds and other water bodies explicitly used for drinking.
- Always boil and filter drinking water from unsafe sources by using a cloth filter to remove the tiny water fleas that carry the larvae.
- Apply approved larvicides such as ABATE to unsafe drinking water sources. This will eliminate the tiny water fleas.
- Educate the communities on the dangers of drinking water from unsafe sources and provide them with new safe sources of drinking water
- Repair broken, safe water sources such as hand pumps if possible.