Presentation on theme: "Iman Diriye and Mikayla Hardy. One of the largest Nematodes Common name is Guinea worm or the “fiery serpent” Disease Caused: Dracunculiasis Definitive."— Presentation transcript:
One of the largest Nematodes Common name is Guinea worm or the “fiery serpent” Disease Caused: Dracunculiasis Definitive host: humans, dogs, horse, cattle, monkeys Intermediate hosts: Cyclops copepods Obligate Parasite Ovoviviparous
Dead female worms have been discovered in remains of mummified 3,000 years old Egyptian The first physical evidence of this was a calcified male Guinea worm in an Egyptian mummy Mentioned in the Bible as the “fiery serpent”
Mainly found in Sub-Saharan African Countries ◦ Mauritania, Mali, Ghana, Togo, etc. 93% of cases are in Nigeria, Ghana, and Sudan Remote Villages of India and Yemen Freshwater habitats preferably stagnant.
Adult females- 600-800mm in length and 2mm in diameter Adult Males- are smaller and do not exceed 40mm in length Mouth is small and triangular with quadrangular scletorized plate Lips are absent in both male and female Larvae: 500-700 micrometers
Humans become infected by drinking unfiltered water containing copepods which are infected with L3 larvae. Following ingestion, the copepods die and release larvae which penetrate the host stomach and intestinal wall and enter the abdominal cavity and retroperitoneal space. The larvae mature into adult worms and reproduce After maturation and copulation, the male worms die and the females migrate into the subcutaneous tissues towards the skin surface. Approximately one year after infection, the adult female worm induces a blister on the skin which ruptures The adult female emerges from the skin at the site of the ruptured blister Person with protruding worms enters water and female releases larvae The larvae must enter water directly to survive and can live for 4-7 days, but only are able to infect intermediate host for a 3 day period. The larvae(L1) are ingested by a copepod and after two weeks and two molts they develop into an infective larvae(L3). Infected copepods are ingested by definitive host and lifecycle is able to repeat.
3 Major Disease Conditions: 1)Emergent Adult Worms-allergic reaction, blisters, and burning pain 2)Secondary Bacterial Infection-bacteria drawn under skin by retreating worms, lack of proper care, third most common mode of entry for tetanus spores 3)Non-emergent Worms-fail to reach skin causing complications in deep tissue, absorbed and calcified, can cause arthritis, paraplegia if worm in central nervous system, can be found in heart
Drinking water containing Cyclops Copepod that are infected with mature L3 larvae No immunity after infection
Symptoms typically do not develop until around 1 year after initial infection. Slight fever, itchy rash, vomiting, diarrhea, nausea, dizziness Blister develops, usually in the lower region of the body (90% of cases) but can occur anywhere on the body Blister grows within several days and is accompanied by a burning pain Emergence of blistered area into cool water often relieves burning but causes blister to bursts releasing larvae
Swelling of skin Redness of skin Generalized infections Abscesses Lock Jaw (tetanus) Infections of the joints causing joint to deform and lock If worm breaks during removal, intense inflammatory response caused by degrading dead worm Can lead to disability
There is no dependable method of diagnosis other than visibility of adult worm from the site of the blister The appearance of an itchy red papule that rapidly transforms into a blister is the first strong indicator of infection Patients that had previous infections are often more aware of presence of the parasite
No drug treatment or vaccine available Removal of worm and care is only treatment ◦ Affected body part is immersed in water to coax more of the worm out ◦ Wound area is cleaned ◦ Gently worm is pulled farther out until reach a resistance ◦ After resistance is met, pulling is stopped so worm does not break ◦ Portion of the worm that is emerged is wrapped around a stick or piece of gauze to maintain some tension so worm cannot retract back into the body ◦ Topical antibiotics applied to prevent secondary bacterial infection ◦ Affected area wrapped in sterile gauze to protect site ◦ Ibuprofen or aspirin are often given to reduce pain and inflammation ◦ Steps are repeated until the entire worm is removed ◦ Can take several days to weeks, depending of length of the worm
Main control is through education Safe drinking water- underground wells free of contaminants, filter drinking water to remove copepods, avoid entering water used for drinking if have a blister or ulcer Early case containment- bandaging lesions to prevent contact with water sources Vector control: larvicide to kill copepods
What disease does Dracunculus Medinensis cause? Where is Dracunculus found geographically? What are 2 symptoms that are observed? What is the definitive host of Dracunculus? Is there a vaccine or drug treatment available?