Is a gastrointestinal infection (GE) a reasonable suspicion given hyperthermia and diarrhea after returning from South Africa?

Gastrointestinal Infection After South African Travel

Yes, gastroenteritis is a highly reasonable suspicion and should be the primary working diagnosis in this patient with fever (105.5°F) and diarrhea after returning from South Africa. 1

Epidemiologic Context

The clinical presentation strongly supports infectious gastroenteritis based on travel medicine data:

• Acute diarrheal disease accounts for 13.6% of all febrile illnesses in returning travelers, making it the most common non-tropical infection diagnosis 1
• Among travelers returning from Africa specifically (51.1% of febrile travelers), gastrointestinal infections are second only to malaria in frequency 1
• Fever is self-reported in up to 30% of travelers' diarrhea cases, and the combination of fever with diarrhea suggests invasive bacterial disease 1, 2

Critical Differential Diagnoses to Exclude

While GE is the most likely diagnosis, three life-threatening conditions must be ruled out immediately in any febrile traveler from Africa:

Malaria (Most Critical)

• Malaria represents 22.2% of all febrile illness in returning travelers and 67.7% of tropical diseases 1
• Every febrile illness after tropical travel, even with diarrhea, must be considered malaria until excluded 1, 3
• Requires three daily blood films or rapid diagnostic testing 1, 2

Enteric Fever (Typhoid/Paratyphoid)

• Accounts for 2.3% of febrile returning travelers 1
• Diarrhea is actually uncommon in enteric fever (unlike typical GE), but fever with headache and abdominal pain are characteristic 1
• Blood cultures have highest yield and should be obtained if clinical suspicion exists 1, 2

Invasive Bacterial Dysentery

• The combination of fever (105.5°F) with diarrhea suggests possible invasive pathogens including Shigella, Salmonella, Campylobacter, or amoebic dysentery 1
• If bloody or mucoid stools develop, this significantly increases concern for invasive disease 1

Recommended Diagnostic Approach

Immediate testing should include:

• Three daily blood films to exclude malaria (mandatory for all febrile returned travelers) 1, 2
• Stool culture for Salmonella, Shigella, Campylobacter, and Yersinia 1, 2
• Blood cultures if enteric fever suspected (high fever, relative bradycardia, or systemic toxicity) 1, 2
• Complete blood count with differential 2

Additional testing if diarrhea persists ≥14 days:

• Parasitic examination for Giardia, Cryptosporidium, Cyclospora, and Entamoeba histolytica 1

Treatment Considerations

Empiric antibiotic therapy is justified given fever with diarrhea suggesting invasive disease:

• Azithromycin 500 mg daily for 3 days or 1-gram single dose is preferred first-line for severe travelers' diarrhea with systemic symptoms 2
• Cephalosporins or fluoroquinolones are alternatives, though fluoroquinolone resistance is increasingly reported from Asia and should be avoided for suspected invasive disease from certain regions 1, 2
• If enteric fever is strongly suspected, ceftriaxone is preferred given increasing fluoroquinolone resistance 2

Common Pitfalls to Avoid

• Never assume simple travelers' diarrhea when fever is present - this constellation demands broader evaluation for invasive pathogens and tropical diseases 2
• Do not delay malaria testing - even one episode of diarrhea with fever requires malaria exclusion 1, 3
• Assess hydration status carefully, as volume depletion is a frequently identified risk factor for diarrhea-related deaths 1
• Consider C. difficile testing only if the patient received antibiotics within the preceding 8-12 weeks 1