Salmonella spp. infection (D) is the most likely diagnosis
In this 23-year-old traveler with acute febrile diarrhea, abdominal tenderness, and fecal leukocytes after consuming undercooked pork, Salmonella spp. infection is the most probable diagnosis.
Clinical Reasoning
The key diagnostic features pointing to Salmonella include:
- Travel-associated exposure with consumption of potentially contaminated pork (roast suckling pig)
- Fever of 38.5°C meeting the threshold for invasive bacterial enteritis
- Abundant polymorphonuclear leukocytes in stool indicating inflammatory/invasive diarrhea
- Acute onset (second day after exposure) consistent with bacterial gastroenteritis
- Generalized abdominal tenderness suggesting systemic inflammatory response
The 2017 IDSA guidelines specifically address this clinical scenario, recommending empiric antimicrobial therapy for travelers with body temperatures ≥38.5°C, which this patient meets 1. The presence of fecal leukocytes confirms an invasive bacterial process rather than toxin-mediated or viral diarrhea.
Why Not the Other Options?
C. difficile colitis (A) is excluded because:
- No recent antibiotic exposure mentioned
- Travel-associated foodborne illness is more consistent with the history
- Typically presents with more severe colitis symptoms
Shigella dysenteriae (B) is less likely because:
- Classic dysentery presents with frequent scant bloody stools with tenesmus 1
- This patient has watery diarrhea (6 episodes/day), not the characteristic small-volume bloody stools
- While Shigella causes fecal leukocytes, the clinical presentation doesn't match bacillary dysentery
Ulcerative colitis (C) is inappropriate because:
- Acute onset after food exposure points to infectious etiology
- IBD should only be considered when symptoms last ≥14 days with unidentified infectious sources 1
Amoebiasis (E) is unlikely because:
- Typically causes subacute symptoms, not acute febrile illness
- Less commonly associated with high fever
- Pork is not a typical transmission vehicle for Entamoeba histolytica
Management Approach
Based on IDSA guidelines, this patient qualifies for empiric antimicrobial therapy because she meets criteria as a recent international traveler with fever ≥38.5°C 1. Empiric treatment should be either a fluoroquinolone (ciprofloxacin) or azithromycin, depending on local resistance patterns and travel history 1.
Common Pitfalls to Avoid
- Don't withhold antibiotics waiting for culture results in febrile travelers—this patient meets clear criteria for empiric therapy
- Don't assume all travel-related diarrhea is self-limited; fever and fecal leukocytes indicate invasive disease requiring treatment
- Consider local antimicrobial resistance patterns from the travel destination when selecting empiric therapy 1
The presence of both fever and inflammatory markers (fecal leukocytes) distinguishes this from simple traveler's diarrhea and mandates both diagnostic workup (stool culture) and empiric antimicrobial therapy while awaiting results.