Dracunculiasis — DTM&H MCQ

Correct answer: A — Case containment and safe water measures

The correct answer is A, case containment and safe water measures. The clinical picture (painful blister, long white worm emerging from the limb after immersion in pond water) is classic for dracunculiasis (Guinea worm disease), caused by Dracunculus medinensis. There is no drug or vaccine that treats or prevents this infection, so control depends entirely on interrupting transmission: preventing the patient from re-entering water sources (to stop the worm releasing larvae), wound care and bandaging, and ensuring access to safe drinking water such as filtered or boreholed supplies. This matches WHO's global eradication strategy, which centres on case containment to prevent water contamination alongside health education and provision of safe water. The unsafe pond water in the stem is the key clue pointing to a waterborne helminth requiring environmental and behavioural control rather than pharmacological treatment. Why the other options are wrong: E. Yellow fever vaccination: Yellow fever is a mosquito borne flavivirus causing fever and jaundice, unrelated to a worm emerging from a foot blister after water contact. D. Praziquantel distribution: Praziquantel treats schistosomiasis and other flukes/tapeworms, but there is no effective drug therapy for Dracunculus medinensis; the worm must be manually and gradually extracted, not chemically treated. C. Indoor residual spraying: This targets indoor resting mosquitoes for malaria vector control and has no role against copepod-borne Guinea worm, which is acquired by ingesting contaminated water, not by insect bites. B. Rabies vaccination: Rabies presents with neurological symptoms following an animal bite, not a foot blister with an emerging worm after wading in stagnant water. Key point: A painful blister with an emerging long white worm after contact with stagnant pond water indicates dracunculiasis, for which there is no cure, so control relies solely on case containment and safe water provision.

Reference: World Health Organization, Dracunculiasis (Guinea-worm disease) fact sheet, 2024, https://www.who.int/news-room/fact-sheets/detail/dracunculiasis-(guinea-worm-disease)