Microbiology · Parasitology (Protozoa, Plasmodium, Helminths, Nematodes, Cestodes, Trematodes)

A 7-year-old child from an endemic area presents with chronic bloody diarrhea, abdominal pain, and rectal prolapse. Stool microscopy reveals barrel-shaped eggs with polar plugs. What is the causative organism?

  • A Enterobius vermicularis
  • B Trichuris trichiura
  • C Ascaris lumbricoides
  • D Ancylostoma duodenale
Correct answer: B. Trichuris trichiura

Explanation

Trichuris trichiura, the whipworm, attaches to the colonic mucosa, causing inflammation, bloody diarrhea, and in heavy infections, rectal prolapse. The eggs are characteristically barrel-shaped with mucous polar plugs. Enterobius causes perianal itching. Ascaris causes pulmonary or biliary symptoms. Ancylostoma causes iron deficiency anemia.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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