Treatment of Shigella Diarrhea
Antibiotic therapy is strongly recommended for Shigella diarrhea, with fluoroquinolones (such as ciprofloxacin) or azithromycin being the first-line treatments based on local susceptibility patterns. 1
Diagnosis and Clinical Presentation
Shigellosis is characterized by:
- Dysentery with bloody, mucoid stools
- Abdominal pain and cramping
- Fever
- Rectal tenesmus
Diagnosis is primarily clinical but can be confirmed through:
- Stool examination for white blood cells
- Stool culture to isolate Shigella species
- PCR testing in specialized settings
Treatment Algorithm
1. Rehydration Therapy
- First-line treatment for all patients with Shigella diarrhea is oral rehydration solution (ORS), especially for those with mild to moderate dehydration 2
- For severe dehydration, intravenous fluids may be necessary
2. Antimicrobial Therapy
Based on the most recent guidelines, antimicrobial therapy is indicated for Shigella infection 2, 1:
For Adults:
- Ciprofloxacin: 500 mg twice daily for 3-5 days
- Azithromycin: 1000 mg single dose or 500 mg daily for 3 days
- TMP-SMX: 160 mg TMP and 800 mg SMX twice daily for 5 days (if susceptible)
For Children:
- Azithromycin: 12 mg/kg on day 1 (max 500 mg), then 6 mg/kg/day for days 2-5
- Third-generation cephalosporin for infants <3 months of age
- TMP-SMX: 10 mg/kg/day TMP and 50 mg/kg/day SMX in two divided doses for 5 days (if susceptible)
Treatment Duration:
- 3-5 days for immunocompetent patients
- 7-10 days for immunocompromised patients
3. Nutritional Support
- Continue feeding during illness
- Resume normal diet as soon as appetite returns
- For breastfeeding infants, continue breastfeeding throughout treatment
Special Considerations
Antibiotic Resistance
- Antibiotic resistance is increasing among Shigella strains globally 3
- Ciprofloxacin and norfloxacin generally maintain good effectiveness (93.3% susceptibility in recent studies) 3
- High resistance has been observed for amoxicillin (100%), ampicillin (86.7%), and cotrimoxazole (66.7%) 3
- Periodic susceptibility testing is recommended, especially in endemic areas
When to Consider Empiric Treatment
Empiric antimicrobial therapy is recommended for 2:
- Infants <3 months with suspected bacterial etiology
- Immunocompetent people with fever, abdominal pain, and bloody diarrhea
- Recent international travelers with fever ≥38.5°C and/or signs of sepsis
Treatment Failure
If no clinical response occurs within 2 days:
- Change to another recommended antibiotic based on local susceptibility patterns
- If no improvement after an additional 2 days, consider alternative diagnoses
Prevention and Public Health Measures
- Hand washing is the single most important preventive measure
- Proper sanitation and safe drinking water
- Isolation of hospitalized patients
- Follow local public health guidelines for return to work, school, or childcare
Complications
Monitor for potential complications such as:
- Hemolytic uremic syndrome
- Reactive arthritis
- Toxic megacolon
These complications require specialized management beyond the standard treatment for shigellosis.