Dracunculiasis

Dracunculiasis (Guinea worm disease) is a waterborne parasitic infection caused by Dracunculus medinensis, acquired by drinking water containing infected copepods (Cyclops).

• Near eradication: under 20 human cases per year in recent years (Chad, South Sudan, Ethiopia, Mali, Angola), down from 3.5 million in 1986.
• The adult female worm (60 to 100 cm) migrates through subcutaneous tissue and emerges, typically from the lower limb, about 1 year after infection.
• Animal infections (dogs, baboons) in Chad complicate eradication.
• Disease is disabling, not usually fatal.

• Asymptomatic for about a year, followed by fever, urticaria, nausea, vomiting, and a painful burning blister on the foot or lower leg.
• Blister ruptures on immersion in water, releasing larvae, with ulcer formation and worm emergence over weeks.
• Secondary bacterial infection, abscess, cellulitis, joint contracture, septic arthritis, and tetanus.
• Severe pain and disability prevent work or school for 4 to 8 weeks.

• Clinical diagnosis by visualisation of the worm emerging from the skin ulcer.
• Microscopy of milky fluid (larvae) after immersing the blister in water.
• Calcified dead worms seen on radiographs.
• Exclude cellulitis, abscess, and dracunculiasis like lesions from other causes (loiasis, onchocerciasis).
• Notification to public health authorities.

• No drug cures or prevents infection. Standard care is slow extraction of the worm by winding it on a small stick over days to weeks (a few centimetres per day), avoiding breakage.
• Wound care: daily cleaning, antiseptic and topical antibiotic, sterile dressings, and oral antibiotics (amoxicillin clavulanate, flucloxacillin) for infection.
• Analgesia with paracetamol and NSAIDs (aspirin or ibuprofen); tetanus prophylaxis.
• Prevent contamination: stop patients entering water sources, case containment centres, and surgical extraction in selected cases.
• Prevention: filtering water through cloth or pipe filters, safe water supply, vector control (temephos, Abate, to kill copepods), health education, and surveillance of dogs and other animal hosts.