Artist/Title/Date
Anonymous painter, Saint Roch, c. 15th–16th century. Tempera on canvas. Pinacoteca di Bari, Bari, Italy.
Description of Disease & Etiology
Dracunculiasis, also known as Guinea worm disease, is caused by the parasitic nematode Dracunculus medinensis. It is primarily transmitted through the ingestion of untreated or unfiltered water containing copepods (small crustaceans) infected with D. medinensis larvae. Thanks to a global eradication campaign, dracunculiasis transmission has been eliminated in many countries where it was once endemic. Currently, five countries remain endemic: Angola, Chad, Ethiopia, South Sudan, and Mali. The adult nematodes of D. medinensis can reach 2- to 3-feet in length. After mating, adult females can cause an ulceration of the skin, as depicted in this artwork. There, contact with water will cause the female to contract and release larvae into the water source.
Signs/Signifiers of Illness
Infected individuals are largely asymptomatic for the first year of infection—the time corresponding to parasite development and sexual maturity and mating. However, when adult females mature and need to release larvae, they approach the skin and form a painful papule. The burning sensation accompanying this can lead an individual to relieve the burning with cold water, which acts as an avenue for the parasite to release larvae. Signs of inflammation can accompany this, and a low-grade fever may also be experienced by patients in this stage. Of course, as depicting in this artwork, portions of the adult worm may be visible and extend superficially.
Pathology
Once ingested, D. medinensis larvae penetrate the stomach and intestinal walls and mature and reproduce in subcutaneous tissues, with males dying after reproduction. Reactions to the dead male worms can cause various inflammatory responses. When the adult female has reached maturity, it can remain exposed on the surface for more than eight weeks, in the open ulcer, releasing larvae during each water contact. Open lesions increase the risk of secondary infections.
Treatment
The primary treatment for dracunculiasis involves manual extraction of the worm. Care must be taken to avoid rupturing the worm, as this can leave fragments behind, causing severe inflammatory reactions. The worm is gently wound around a small stick and slowly pulled out over hours to days to minimize tension and prevent rupture. Currently, there are no effective oral anthelmintics for dracunculiasis. Anti-inflammatory medications may help reduce edema and pain associated with the infection. Overall, the guiding principles of treating this disease revolve around prevention, including water filtration and thorough cooking of aquatic animals before ingestion.
Social Determinants of Illness
Dracunculiasis predominantly affects rural communities in low-income countries where surface water sources are the primary water supply for daily needs. These conditions facilitate the continued transmission of the disease.
Author(s): Victoria Rhodes