Phlebotomus argentipes (sandfly) transmits Leishmania donovani (kala-azar) only in the Indian subcontinent. The characteristic feature that makes it an efficient vector despite being a weak flier is:

• A It breeds in clear stagnant water and bites during dawn
• B It only feeds on cattle and is a dead-end host for Leishmania
• C It can survive at altitudes >2000 m making altitude-based control impossible
• D It is endophagic and endophilic, biting indoors and resting in cool dark places (cracks in mud walls, peridomestic habitats) ✓

Explanation

Phlebotomus argentipes is uniquely endophagic (biting indoors) and endophilic (resting indoors), which concentrates its transmission activity within households — the primary reason for efficient peridomestic kala-azar transmission in Bengal, Bihar, and eastern UP. Its small size (2–3 mm) allows it to pass through standard bed nets (not fine-mesh nets), but its indoor resting habits make indoor residual spraying (IRS) with DDT historically effective. It does not breed in water but in moist organic debris in soil cracks, animal burrows, and building foundations.

Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.