Travelers' Diarrhea and Typhoid Fever

Symptoms

• Travelers' diarrhea (typical onset 4-14 days into travel): ≥3 loose stools/24 h with nausea, cramping, urgency, low-grade fever; usually self-limited in 3-5 days
• Dysentery: bloody/mucoid stools, high fever, tenesmus — suggests Shigella, Campylobacter, EHEC, or amebiasis
• Typhoid fever (incubation 6-30 days): stepwise rising fever to 39-40°C, relative bradycardia (Faget sign), prolonged headache, abdominal pain, constipation (early; diarrhea later in 'pea-soup' form), splenomegaly, rose spots (faint salmon-colored macules on trunk in ~30%), encephalopathy in severe disease
• Intestinal complications (week 3): perforation and hemorrhage at Peyer patches
• Chronic carrier state (~2-5%): persistent shedding from gallbladder; classic 'Typhoid Mary'

Signs / physical exam

• TD: signs of dehydration; non-distended abdomen with diffuse tenderness
• Typhoid: relative bradycardia for degree of fever, hepatosplenomegaly, rose spots (small, faint macules on trunk), altered mental status in severe cases
• Perforation: peritoneal signs, hypotension

Classic findings

Returning traveler from South Asia with stepwise fever, relative bradycardia, rose spots, and abdominal pain — typhoid fever. Traveler with watery, non-bloody diarrhea on day 3 of a trip to a tropical destination — most likely ETEC travelers' diarrhea.

Diagnostic criteria

Travelers' diarrhea: clinical syndrome + travel history. Typhoid: positive culture (blood, bone marrow, or stool) for Salmonella Typhi.

Labs

• Travelers' diarrhea: stool culture, multiplex PCR panel, O&P if persistent; not routinely needed for mild self-limited illness
• Typhoid: blood cultures (highest yield first week of illness; sensitivity 40-80%), bone marrow culture (highest yield, ~90%, but invasive), stool culture (later in illness), urine culture
• CBC: typhoid often shows normal or low WBC with relative bradycardia; eosinopenia
• CMP, LFTs (mild transaminitis in typhoid)
• Serology (Widal test) — poor specificity; not recommended where culture available
• Malaria smears in febrile returned traveler — coinfection or alternative diagnosis

Imaging

• Abdominal radiograph or CT if perforation suspected (free air, ileal pneumatosis)
• Ultrasound for hepatosplenomegaly, abscess

First-line

• Travelers' diarrhea — based on severity:
• • Mild: oral rehydration, loperamide (avoid if dysenteric); antibiotics not required
• • Moderate: azithromycin 1 g PO × 1 (or 500 mg daily × 1-3 days) — preferred globally given fluoroquinolone resistance, especially in Asia for Campylobacter
• • Alternative: ciprofloxacin 500 mg PO BID × 1-3 days (avoid in Asia due to Campylobacter resistance); rifaximin 200 mg PO TID × 3 days (non-absorbed; good for non-invasive ETEC; not effective for invasive infection)
• • Severe/dysenteric: azithromycin 1 g PO × 1 (preferred) — covers Shigella, Campylobacter; do NOT use loperamide
• Typhoid fever:
• • Azithromycin 1 g PO × 1 then 500 mg daily × 5-7 days for uncomplicated outpatient cases
• • Ceftriaxone 2 g IV daily × 7-14 days for severe disease or hospitalized patients
• • Carbapenems (meropenem) for XDR strains from Pakistan
• • Dexamethasone for severe disease with shock/altered mental status (reduces mortality)
• • Fluoroquinolones (ciprofloxacin) historically first-line but increasing resistance — reserve for known susceptible strains

Second-line / adjunct

• Prevention — food and water precautions ('boil it, cook it, peel it, or forget it'); typhoid vaccine for travelers to endemic areas (inactivated Vi polysaccharide IM single dose or live attenuated oral Ty21a 4-dose regimen)
• Chemoprophylaxis: rifaximin for high-risk short-term travelers with comorbidities (not routinely recommended due to resistance concerns)
• Bismuth subsalicylate 524 mg QID — modestly effective TD prophylaxis; many side effects
• Chronic typhoid carriers: prolonged ciprofloxacin (4-6 weeks) or cholecystectomy