A 42-year-old woman with a history of gallstones presents with recurrent Salmonella serotype Typhi bacteremia. Stool cultures remain positive for months despite antibiotic therapy. The chronic carrier state of S. Typhi is most commonly established in which anatomical site?

• A Distal ileum (Peyer patches)
• B Mesenteric lymph nodes
• C Bone marrow
• D Gallbladder ✓

Explanation

The gallbladder is the primary site of chronic S. Typhi carriage, especially in patients with gallstones. The organism forms biofilms on stone surfaces, shielding it from antibiotics. This is why cholecystectomy combined with antibiotics may be needed to eradicate carriage. Mesenteric nodes and Peyer patches are involved in acute infection. Bone marrow is a site of replication but not chronic carriage.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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