Dracunculus medinensis Flashcards
What is the scientific name of the Guinea worm, and what disease does it cause?
Dracunculus medinensis (Guinea worm, dragon worm, fiery serpent) is a nematode that causes dracunculiasis, also known as guinea worm disease.
What are the definitive and intermediate hosts in the life cycle of Dracunculus medinensis?
• Definitive host: Human
• Intermediate host: Cyclops
What is the infective stage of Dracunculus medinensis, and how does infection occur?
• Infective stage: L3 larva
• Mode of infection: Drinking unfiltered water containing infected Cyclops.
What are the three major conditions that can occur from Dracunculus medinensis infection?
- Emergent adult females cause hot and painful blisters.
- Secondary bacterial infections.
- Non-emergent worms that die under the skin cause allergic reactions (usually the male).
What are some complications of Dracunculus medinensis infection?
- Wound infections
- Cellulitis
- Abscesses
- Sepsis
- Septic arthritis
- Joint deformities
- Tetanus
What are the diagnostic methods for Dracunculus medinensis infection?
- Clinical picture, local skin lesions (papule, blister & ulcer).
- Outline of the female worm may be seen under the skin (enhanced by reflected light).
- Discharge of larvae: by cooling the ulcerated area or by contact with water.
- X-ray shows calcified females.
- Intradermal test & serological tests.
- High eosinophilia.
What are the control measures for preventing Dracunculus medinensis infection?
- Filtering or boiling of drinking water.
- Destroying the Cyclops using copper sulphate or chlorine.
- Patients are not allowed to bathe in water used for drinking.
What are the three groups of filarial worms based on their location in the body?
- Lymphatic filariasis: Caused by Wuchereria bancrofti, occupying the lymphatic system.
- Subcutaneous filariasis: Caused by Loa loa (the eye worm) and Onchocerca volvulus, occupying the subcutaneous layer of the skin.
- Serous cavity filariasis: Caused by Mansonella perstans, occupying the serous cavity of the abdomen.
What are microfilariae, and how do they develop further in the life cycle of filarial worms?
• Microfilariae: Modified eggs produced by female worms, capable of living a long time in the vertebrate host but cannot develop further until ingested by an intermediate host and vector, an insect.
• Microfilariae transform into infective larvae in the insect and are deposited in the next host when the insect takes a blood meal.
