What is Dracuncullosis?
Dracuncullosis or Rishta – helminthiasis from a group of nematodoses, caused by female worms of the Dracunculus medinensis. Distributed in the tropics and subtropics of Africa and Asia. The name dracuncullosis comes from the Latin expression “defeat by little dragons.” At the beginning of the 20th century, Rishta disease was widespread in many countries in Africa and Asia. According to reports, in the 1950s, there were about 50 million cases of the disease. Thanks to the joint efforts of the international community and endemic countries, the number of cases of rishta has decreased to almost 16,000 by 2004. Currently, risht disease is spread only in 11 African countries, including Sudan, Nigeria, Ghana, Mali, Niger and Togo. A small number of cases were also reported in Benin, Burkina Faso, Côte d’Ivoire, Ethiopia and Mauritania.
Causes of Dracuncullosis
The causative agent of dracuncullosis is a rishta, which is a worm. This is a large nematode (roundworm), Dracunculus medinensis. The female helminth reaches a length of 32-120 cm with a thickness of 0, 5-1, 7 mm, the male – 12-30 cm and 0, 2-0, 4 mm, respectively.
Pathogenesis during Dracuncullosis
Larvae swallow freshwater Cyclops crustaceans of the genus Cyclops or Eucyclops (intermediate hosts), in which they molt and become invasive after 4-14 days. After invasion into the human body, the larvae penetrate through the intestinal wall, mature in the retroperitoneal space and migrate to the subcutaneous tissue. After 12 months, a pseudo furuncle is formed above the head end of the female, exposing the subcutaneous course of the parasite: the uterus bulges into the gap, when in contact with water, it breaks and tissue fluid containing the larvae comes out.
Symptoms of Dracuncullosis
The main source of infection is a sick person who is most epidemiologically dangerous in the first two weeks after breaking the helminth cuticle and the mass release of larvae into the water. Susceptibility to dracuncullosis is universal. A person becomes infected by drinking water containing cyclops affected by rishta larvae. Cyclops die in his stomach, and the larvae that have freed themselves penetrate through the stomach wall into the abdominal cavity, from which they pass through the lymphatic channels to soft tissues. After about 3 months. the female takes root in the subcutaneous tissue or intermuscular connective tissue, where in one year its full maturation occurs, and the head end of the mature female approaches the skin. In the skin, a bubbly bulge with a diameter of up to 2-7 cm is formed. After 9-14 months after infection, allergic phenomena occur (urticaria, asthma attacks, etc.), as well as nausea, vomiting, diarrhea, fainting. On the skin around the place of parasitism of the helminth bubble forms. Often in this place is visible parasite. The bubble bursts a few days later with the formation and subsequent rejection of the necrotic mass. People affected by the disease experience excruciating pain – as if the foot were in flames. Burning pain causes people to jump into reservoirs, often the only sources of drinking water in communities. When the feet of an infected person are immersed in water, at the foot of the Rishta it lays thousands of larvae. Then the larvae are swallowed by water fleas living in the water, and the cycle begins again – when a person drinks water, he becomes infected with a disease. Often in 1-2 months. before the parasite’s head end emerges, from under the skin, at the place of its location, an edema of allergic tissues forms, accompanied by sharp pain, regional lymphadenitis develops. Most often, rishty are localized in the subcutaneous tissue of the lower extremities, sometimes the upper, less often the abdomen, back, etc. The bubble formation formed around the head end of the parasite resembles furuncle, but without a pronounced inflammatory reaction and infiltration around. At the location of the helminth in the surface layers of the subcutaneous tissue, a spherical seal is palpated. With the localization of the bubble formations in the joints develop synovitis, contracture and ankylosis of the joints. With the accession of a secondary infection, an abscess, phlegmon may be formed, gangrene of the limb, sepsis may develop.
Diagnosis of Dracuncullosis
- Detection of the head of the mature parasite at the bottom of the ulcer.
- Detection of larvae in the ulcers.
- Blood test: eosinophilia, an increase in the content of γ-globulin in the serum.
Treatment of dracuncullosis is carried out by carefully removing the parasite from the tissues in compliance with the rules of asepsis. Inside prescribe antihistamines. Apply drugs that cause the death of the parasite and reduce the inflammatory response of the tissues – ambilgar, mintezol, niridazole. When infected with dracuncullosis, it is necessary to be vaccinated against tetanus, especially if you have not performed its prevention for a long time. The prognosis is usually favorable; with complications may be questionable.
Prevention of Dracuncullosis
There are a number of low-cost methods for the prevention of human infection:
- Ensuring safe supplies of drinking water.
- Filtration of drinking water using a sieve with small cells.
- Intensive patient care (a health worker can wash the ulcer, gradually remove the wicker, sanitize and bandage the affected area in order to prevent secondary bacterial infection).
- Preventing the use of water by infected people in order to alleviate pain.
- Intensive health education and social mobilization.
- Treatment of water bodies (water sources) with an abatom (a pesticide that kills water fleas).