A patient undergoes colonoscopy showing adult worms with a prominent buccal capsule containing cutting plates. The laboratory diagnosis of iron deficiency anemia in this patient is BEST confirmed by:

• A Direct smear showing oval eggs with a thin transparent shell and 4-8 cell stage embryo ✓
• B Stool concentration technique showing filariform larvae
• C Direct stool smear showing decorticated eggs with a segmented embryo
• D Stool examination showing barrel-shaped eggs with mucous plugs at both poles

Explanation

Ancylostoma duodenale (hookworm with cutting plates in buccal capsule, causing blood-loss anemia) produces oval eggs with a thin transparent shell containing a 4-8 cell morula stage at time of passage; these are the typical hookworm eggs. Filariform larvae in stool are seen in Strongyloides stercoralis (autoinfection cycle). Barrel-shaped eggs with mucous plugs describe Trichuris trichiura (whipworm). Decorticated eggs with segmented embryos describe Ascaris lumbricoides fertilized eggs that have lost their outer albuminous coat.

Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.