http://dx.doi.org/10.5125/jkaoms.2016.42.2.67 INVITED SPECIAL ARTICLE pISSN 2234-7550·eISSN 2234-5930 Dracunculiasis in oral and maxillofacial surgery Soung Min Kim1,2 1Oral and Maxillofacial Microvascular Reconstruction Lab, Sunyani Regional Hospital, Sunyani, Brong Ahafo, Ghana, 2Department of Oral and Maxillofacial Surgery, Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Korea Abstract (J Korean Assoc Oral Maxillofac Surg 2016;42:67-76) Dracunculiasis, otherwise known as guinea worm disease (GWD), is caused by infection with the nematode Dracunculus medinensis. This nematode is transmitted to humans exclusively via contaminated drinking water. The transmitting vectors are Cyclops copepods (water fleas), which are tiny free- swimming crustaceans usually found abundantly in freshwater ponds. Humans can acquire GWD by drinking water that contains vectors infected with guinea worm larvae. This disease is prevalent in some of the most deprived areas of the world, and no vaccine or medicine is currently available. Inter- national efforts to eradicate dracunculiasis began in the early 1980s. Most dentists and maxillofacial surgeons have neglected this kind of parasite infec- tion. However, when performing charitable work in developing countries near the tropic lines or other regions where GWD is endemic, it is important to consider GWD in cases of swelling or tumors of unknown origin. This paper reviews the pathogenesis, epidemiology, clinical criteria, diagnostic criteria, treatment, and prevention of dracunculiasis. It also summarizes important factors for maxillofacial surgeons to consider. Key words: Dracunculiasis, Dracunculus medinensis, Guinea worm disease, Neglected tropical diseases, Swelling of unknown origin [paper submitted 2016. 3. 24 / accepted 2016. 3. 26] I. Introduction Until recently, the people of the Dogon region in Mali re- ferred to GWD as “the disease of the empty granary”3-5. Dracunculiasis, also known as guinea worm disease Dracunculiasis can cause temporary incapacitation and can (GWD), is a parasitic infection of humans caused exclusively sometimes be associated with permanent disability, resulting by the water-borne nematode Dracunculus medinensis. The in fatal damage to the body. It is highly prevalent in economi- common name of this disease is derived from its prevalence cally disadvantaged communities in tropical regions, includ- on the gulf of Guinea. Moreover, this disease has been known ing Africa and Southern Asia, and has been associated with to humans since antiquity1-3. Dracunculiasis was first men- reduced economic status and low levels of education6,7. Al- tioned in the Turin Papyrus in the fifteenth century BC by the though rapid and significant progress has been made world- Egyptians and is also described in the Old Testament. Since wide regarding the prevention and treatment of GWD, thus then, it has also been described by ancient Greek, Roman, reducing the incidence of GWD by more than 99%, some Arab, Persian, and Indian physicians4,5. The “fiery serpents” developing countries still have high rates of morbidity and of the Israelites are presently believed to be guinea worms. mortality8,9. In the field of oral and maxillofacial health care, only a single report10 has described a case of dracunculiasis; this Soung Min Kim case was from a developing tropical country. Most dentists Oral and Maxillofacial Microvascular Reconstruction Lab, Ghana Health Service, Sunyani Regional Hospital, P.O. Box 27, Sunyani, Brong Ahafo, Ghana and maxillofacial surgeons have neglected or are not even TEL: +233-249-681-906 familiar with this parasitic infection or its sequelae. How- E-mail: [email protected] ORCID: http://orcid.org/0000-0002-6916-0489 ever, since the amount of charitable work (i.e., free-of-charge surgery) in developing countries has increased recently, it is CC This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/), important for dentists and maxillofacial surgeons to have ac- which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. curate knowledge of and to be familiar with the appropriate Copyright Ⓒ 2016 The Korean Association of Oral and Maxillofacial Surgeons. All rights reserved. treatment protocols for this frequent tropical disease. When This study was supported by a grant of the Korean Health Technology R&D Project, Ministry of Health & Welfare, Republic of Korea (HI15C0689). 67 J Korean Assoc Oral Maxillofac Surg 2016;42:67-76 we found any swelling or tumors of unknown origin in pa- copulation, whereas females grow to a length of 60 to 100 tients in developing countries near the tropic lines, parasite cm and migrate toward the subcutaneous skin tissue. At ap- infection (e.g., dracunculiasis) was a tentative clinical diag- proximately 10 to 14 months after ingesting the contaminated nosis. water, the female worm induces a painful blister that is pre- This paper reviews the pathogenesis, epidemiology, clini- dominantly found on the skin of the lower extremities. When cal criteria, diagnostic criteria, treatment, and prevention of the blister ruptures, larvae are released on contact with water dracunculiasis. It also summarizes important factors for max- by emergence of the adult female worm. These immature illofacial surgeons to consider. first-stage larvae can live in the water for 3 days and can be ingested by Cyclops water fleas to become second-stage lar- II. Life Cycle and Pathogenesis of vae. The infectious third-stage larvae develop after about two the Guinea Worm more weeks, after which the transmission cycle is perpetu- ated by humans drinking stagnant unfiltered water containing 1. Life cycle of guinea worm infected Cyclops fleas1-5,8,11.(Fig. 1) No vaccine has yet been developed for the mass treatment Dracunculiasis is transmitted exclusively to humans via of this disease12,13. However, considering the life cycle of the the ingestion of drinking water contaminated with D. medi- guinea worm, various opportunities exist for prevention of nensis-infected Cyclops, a copepod that is the intermediate GWD transmission at different points. For instance, contami- host of this parasite. After drinking the water, the Cyclops nated sources of drinking water can be avoided, unsafe water fleas die and release D. medinensis larvae, which penetrate can be filtered with cloth and fine-mesh strainers, sources of the human stomach and intestinal wall and then enter the ab- drinking water can be improved, and adequate measures can dominal cavity and retroperitoneal space. These third-stage be taken to control the vectors of transmission. larvae develop and mature into adults. Male worms die after Intermediate host, water flea-2 weeks Fig. 1. Schematic drawing of the trans- mission cycle of Dracunculus medi- nensis. 1) A person drinks well or pond Third-stage larva water containing water fleas (Cyclops) that are infected with mature third- Larva released stage larvae. 2) Stomach gastric juices Main host, digest the water fleas, thus releasing human-10 to 14 months worm larvae that move to the abdomi- nal tissue, where they grow and mate. 3) Fertilized female worms migrate to various body regions, usually the lower extremities. 4) At 10 to 14 months after Water flea Ginea worms migration, the worm begins to emerge penetrated through the skin at a painful blister site. 5) Upon contact with water, the emerg- ing worm releases immature first-stage larvae into the water source. 6) Water fleas consume worm larvae that resist digestion. 7) In two weeks, the larvae mature to third-stage infected larvae First-stage larva within the water flea, which can infect humans. Free living, Soung Min Kim: Dracunculiasis in oral and in water-within3days maxillofacial surgery. J Korean Assoc Oral Maxillofac Surg 2016 68 Dracunculiasis in oral and maxillofacial surgery 2. Pathogenesis of dracunculiasis migrate into the connective tissues, where they develop into mature worms. Mating occurs about 3 months after the ini- Adult D. medinensis parasites mature only in humans tial infection; the males (1-4 cm×0.4 mm) are much smaller over a period of 10 to 14 months, during which the infection than the females and die after mating. Female worms move manifests no symptoms or outward signs. After this period, through the connective tissues and usually reach the lower a thin white female adult worm, which is up to 60 to 100 cm extremities by about 10 to 14 months postinfection.(Fig. 1) long and 1.5 to 2.0 mm thick, emerges slowly and painfully Although parasites resembling D. medinensis have been through a ruptured blister on the skin5,6,14,15. Female worms observed in dogs and other animals, no other host or environ- inhabit human subcutaneous tissue and can emerge from mental reservoir of D. medinensis has been found outside of any skin surface on the body, including the face, abdomen, human beings. The immature first-stage larvae survive only arm, and lower extremities16 (Fig. 2); however, most female a few days outside of the human body and must be ingested worms emerge from the leg, ankle, or foot. A dozen or more by a water flea for the life cycle to continue. For this reason, worms have even emerged simultaneously from a single pa- even though water fleas are ubiquitous in stagnant surface tient. sources of freshwater, GWD is vulnerable to complete eradi- Most of the interior body of the female worm is occu- cation. However, more recently the presence of other hosts pied by the uterus, which contains thousands of first-stage (i.e., dogs) was proposed as a possible reason for why GWD larvae5,6,14,15. A blister is formed on the human skin around has been difficult to eradicate19. the anterior end of the worm; this blister ruptures when it is exposed to water. The female worm protrudes its anterior III.