The guinea worm (Dracunculus medinensis) is a long, thin parasitic nematode (roundworm) that infects humans and some animals such as dogs. The infection is rarely fatal, but its late stage is painful. The infection is also called dracunculiasis (pronounced dra-KUNK-you-LIE-uh-sis). In 1986, the world health community began a campaign to eliminate the guinea worm worldwide.
In early 1980s, guinea worms infected 10–15 million people annually in central Africa and parts of Asia. Guinea worms were endemic to 16 countries in sub-Saharan Africa as well as Yemen, India, and Pakistan. Every year, about 3.5 million people were stricken and at least 100 million people were at risk.
Under the leadership of former U.S. president Jimmy Carter, a consortium of agencies, institutions, and organizations—the World Health Organization (WHO), UNICEF, the United Nations Development Program (UNDP), the World Bank, bilateral aid agencies, and the governments of many developed countries—banded together to fight this disease with the goal of completely wiping out the guinea worm. If successful, this would be only the second global disease affecting humans ever completely eradicated (smallpox was the first in 1977) and the only time that a human parasite would have been totally exterminated worldwide.
To survive, guinea worms require three factors: water during the embryo stage, an intermediate host during the larval stage, and a human host to grow to adulthood. In bodies of water, such as stagnant ponds, guinea worm embryos are eaten by tiny, copepod water fleas (Cyclops species). Guinea worm disease starts when people drink water contaminated with these fleas. The fleas are killed by acid in the stomach and the guinea worm larvae are released.
The released larvae burrow into the lining of the intestine and mate. The males die, but the females continue to grow and mature for as long as one year. The worms can grow up to 3 ft. (1 m) long but are only 1–2 mm thick. Each female contains up to three million embryos. More than one guinea worm can infect a person at the same time. During this period, the infected individual is symptom free.
Using drugs to combat guinea worms has proved ineffective. Most people infected with the worm rely on traditional practices. The worm is extracted by gently and gradually pulling it out of the body and winding it around a small strip of wood. Sometimes the entire worm can be extracted in a few days, but the process usually takes weeks. If the worm is removed too fast and breaks off, the part left in the body can die, leading to serious secondary infections. If the worm exits the body through a joint, permanent crippling can occur. Extraction often is complemented by traditional herbs and oils to treat the wound site and antibiotics when available. Such treatment can ease extraction and may help prevent secondary infections.
Although people rarely die as a direct effect of the parasite, the social and economic burden at both the individual and community level is great. During the weeks that worms are emerging, victims usually are unable to work or carry out family duties. This debilitation often continues for several months after worms are no longer visible. In severe cases, arthritis-like conditions can develop in infected joints, and the person may be permanently crippled.
There is no cure for guinea worm disease once the larvae are ingested. There is no vaccine and having been infected once does not provide immunity to future infections. Before the push for eradication, many people in affected villages experienced guinea worm infection year after year.
The only way to break the infective cycle is through behavioral changes. Community health education, providing clean water from wells or by filtering or boiling drinking water, eliminating water fleas by chemical treatment, and teaching infected individuals to stay out of drinking-water supplies are the only solutions. This change requires changing traditional behaviors.
Huge strides have been made in the campaign to eliminate the guinea worm, and worldwide eradication of the worm appears, as of 2018, to be near. Pakistan was the first formerly infested country to be declared completely free of these parasites. Many other countries followed. In 1990, guinea worm disease occurred in 20 countries. By 2011 that number was down to four, all in Africa: South Sudan, Mali, Ethiopia, and Chad. These four countries reported a total of only 1,060 cases, down from the millions reported 25 years earlier. In 2017 only 30 cases were reported, 15 cases came from 14 villages in Chad and 15 cases from 6 villages in Ethiopia. About 830 dogs were also reported as infected. In previous years, cases had been reported in South Sudan, but in March 2018, there had been no reported cases in this country for 15 months, a period longer than the lifespan of the worm. In July 2018, three new cases of guinea worm disease were discovered in South Sudan, dashing hopes the disease had been eliminated worldwide.
An encouraging outcome of this crusade is the demonstration that public health education and community organization can be effective even in some of the poorest and most remote areas. Village-based health workers and volunteers conduct disease surveillance and education programs, allowing funds and supplies to be distributed in an efficient manner. Once people understand how the disease spreads and what they need to do to protect themselves and their families, they change their behavior. A great advantage of this community health approach is that educating villagers about the importance of proper sanitation and clean drinking water is effective not only against dracunculiasis, but also can help eliminate many other waterborne diseases.
See also Parasites ; Water quality ; Waterborne diseases .
McNeil, Donald G., Jr. “South Sudan Halts Spread of Crippling Guinea Worms.” New York Times. Published electronically March 22, 2018. https://www.nytimes.com/2018/03/22/health/south-sudan-guinea-worms.html
Centers for Disease Control and Prevention (CDC). “Parasites—Guinea Worm.” http://www.cdc.gov/parasites/guineaworm/index.html (accessed March 22, 2018).
Dhawan, Vinod, K. “Dracunculiasis.” Medscape Reference. http://emedicine.medscape.com/article/997617-overview (accessed March 22, 2018).
World Health Organization “About Guinea-worm Disease.” http://www.who.int/dracunculiasis/disease/en (accessed March 22, 2018).
United States Centers for Disease Control and Prevention (CDC), 1600 Clifton Rd., Atlanta, GA, 30329-4027, (404) 639-3534, (800) 232-4636; TTY: 888-232-6348, http://www.cdc.gov .
United States Environmental Protection Agency (EPA), Ariel Rios Bldg., 1200 Pennsylvania Ave. NW, Washington, DC, 20460, (202) 272-0167; TTY 202-272-0165, http://www.epa.gov .
Tish Davidson, AM