A physician-validated, board-style question from the Active Transport QBank. Try it, then check the reasoning for every option.
A 21-year-old man presents to the physician with complaint of fever and non-bloody diarrhea for the past 3 days, after a week of constipation. He and his family recently returned from a summer spent in New Delhi, India visiting relatives. Physical examination reveals abdominal tenderness and a pink macular rash extending from his trunk to his upper arms. His vital signs are as follows: temperature is 99.7°F (37.6°C), blood pressure is 120/72 mmHg, pulse is 85/min, and respirations are 16/min. Which of the following drugs would be most effective in treating this patient’s condition?
-
A
CiprofloxacinCorrect. Ciprofloxacin (or ceftriaxone for resistant strains) is first-line for typhoid fever caused by Salmonella Typhi, which fits this traveler's prolonged fever, rose spots, and ileal pattern.
-
B
MetronidazoleIncorrect. Metronidazole covers anaerobes and parasites (Giardia, Entamoeba) but does not effectively treat Salmonella Typhi.
-
C
Oral vancomycinIncorrect. Oral vancomycin is for C. difficile colitis and is not systemically absorbed; it would not reach Salmonella in Peyer patches or bloodstream.
-
D
PenicillinIncorrect. Penicillin has no reliable activity against gram-negative Salmonella Typhi.
-
E
Trimethoprim-sulfamethoxazoleIncorrect. TMP-SMX is used for uncomplicated UTIs and some enteric infections, but multidrug-resistant Salmonella Typhi from South Asia is reliably treated with fluoroquinolones or third-generation cephalosporins, not TMP-SMX.
↑ Tap an answer to reveal the reasoning
Answer: A. A returned traveler from India with prolonged fever, abdominal pain, initial constipation followed by diarrhea, and a faint pink macular rash on the trunk (rose spots) has typhoid fever caused by Salmonella enterica serotype Typhi. The classic course is a week of stepwise fever and constipation, then GI symptoms, with hepatosplenomegaly, relative bradycardia, and rose spots in the second week. Untreated, it can progress to intestinal perforation from terminal ileum lymphoid hyperplasia.
First-line treatment for typhoid fever today is a fluoroquinolone such as ciprofloxacin, or a third-generation cephalosporin (ceftriaxone) when fluoroquinolone resistance is suspected (increasingly common from South Asian strains). Chloramphenicol was historically used but is largely replaced because of aplastic anemia risk.
Metronidazole would treat Giardia or amebiasis, both of which can cause traveler's diarrhea but not the typhoidal syndrome with rose spots. Oral vancomycin treats Clostridioides difficile and is not absorbed systemically. Penicillin has no useful activity against Salmonella Typhi. Carriers (Salmonella in the gallbladder) may need cholecystectomy.
**Why each option:**
**A.** Correct. Ciprofloxacin (or ceftriaxone for resistant strains) is first-line for typhoid fever caused by Salmonella Typhi, which fits this traveler's prolonged fever, rose spots, and ileal pattern.
**B.** Metronidazole covers anaerobes and parasites (Giardia, Entamoeba) but does not effectively treat Salmonella Typhi.
**C.** Oral vancomycin is for C. difficile colitis and is not systemically absorbed; it would not reach Salmonella in Peyer patches or bloodstream.
**D.** Penicillin has no reliable activity against gram-negative Salmonella Typhi.