Cases of a painful blister on the lower leg that ulcerates on immersion in pond water, releasing motile larvae, are reported from a district relying on untreated step wells. The adult female worm is extracted by gradual winding onto a stick over several days. Which arthropod is the intermediate host of this helminth?

• A Phlebotomus, the sandfly
• B Simulium, the blackfly
• C Cyclops, a freshwater copepod ✓
• D Tabanus, the deerfly

Explanation

The gravid female Dracunculus medinensis migrates to subcutaneous tissue of the legs and forms a blister that ruptures on contact with water, discharging first stage larvae. These larvae are ingested by the copepod Cyclops, and humans acquire infection by drinking water containing infected copepods. Simulium transmits Onchocerca volvulus, Phlebotomus transmits Leishmania species, and Tabanus is the vector of Loa loa, which eliminates all three distractors.

Reference: Paniker's Textbook of Medical Parasitology, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.