31 August 2026Chapter 3: Gastrointestinal disordersPDF page 116
Shigellosis
Full paraphrased clinical guide to shigellosis, bloody diarrhoea, risk groups, complications, treatment, nutrition, and epidemic considerations.
This guide supports clinical education and care navigation. It does not replace bedside judgement, emergency care, specialist advice, or local treatment protocol.
Seek urgent care
- Bright red blood in stool with severe dehydration, seizure, altered mental status, or fever above 39 C.
- Bloody diarrhoea in a child under 5 years, malnourished patient, child after measles, or adult over 50 years.
- No improvement after 48 hours of appropriate treatment, signs of sepsis, rectal prolapse, or inability to drink.
Overview
Shigellosis is a highly contagious bacterial infection that causes bloody diarrhoea.
Four Shigella serogroups are recognised. Shigella dysenteriae type 1 is the strain most associated with large outbreaks and higher case-fatality risk.
Patients at higher risk
- Children under 5 years.
- Malnourished patients.
- Children recovering from measles.
- Adults over 50 years.
Clinical features
- Diarrhoea with visible bright red blood, with or without fever.
- Abdominal pain and rectal pain are common.
- Severe illness may include high fever, severe dehydration, seizure, or altered mental status.
- Complications include febrile seizures, rectal prolapse, septicaemia, intestinal complications, and nutritional deterioration.
Laboratory and epidemic context
- Laboratory testing is useful when available, especially at the start of an outbreak or when treatment failure suggests resistance.
- In epidemic settings, antimicrobial sensitivity testing helps guide first-line treatment.
- Assess hydration, nutrition, fever, abdominal signs, mental status, and public-health risk.
Treatment
Admit patients with serious illness or life-threatening risk factors. Treat patients without serious signs or risk factors as outpatients when hydration and follow-up are reliable.
- Avoid ciprofloxacin in pregnancy when possible; if ceftriaxone is unavailable, use the safest available effective antibiotic according to protocol.
- If there is no improvement 48 hours after second-line treatment, reassess and treat for amoebiasis when clinically appropriate.
- Use paracetamol for pain or fever when indicated. All opioid analgesics and loperamide or other antidiarrhoeals are contraindicated because they slow peristalsis and may worsen disease.
| Situation | Medicine and dose |
|---|---|
| Oral administration possible and strain sensitive, or no sensitivity test available | Ciprofloxacin PO for 3 days. Children: 15 mg/kg twice daily, maximum 1 g/day. Adults: 500 mg twice daily. |
| Severe infection, oral administration not possible, or pregnancy | Ceftriaxone IM for 3 days. Children: 50 to 100 mg/kg once daily, maximum 1 g/day. Adults: 1 to 2 g once daily. |
| Medicine | Dose and duration |
|---|---|
| Azithromycin PO for 5 days | Children: 12 mg/kg once on day 1, then 6 mg/kg once daily on days 2 to 5. Adults: 500 mg once on day 1, then 250 mg once daily on days 2 to 5. |
| Cefixime PO for 5 days | Children: 8 mg/kg once daily, maximum 400 mg/day. Adults: 400 mg once daily. |
Nutrition and supportive care
- Rehydrate with ORS according to WHO dehydration protocols and ongoing losses. Use IV care when dehydration is severe or oral intake is unsafe.
- Give zinc sulfate to children under 5 years using the acute diarrhoea dosing schedule.
- Provide frequent meals and nutritional supplementation: about 2500 kcal/day during hospitalisation and about 1000 kcal/day as outpatient supplementation when feasible.
- Manage complications such as rectal prolapse, septicaemia, seizures, intestinal obstruction or perforation, and haemolytic uraemic syndrome according to the relevant emergency pathways.
- Watch for malnutrition, dehydration recurrence, persistent fever, worsening stool frequency, and treatment failure.
Prevention
- In epidemic contexts, isolate hospitalised patients and exclude treated outpatient children from school according to public-health guidance.
- Prevention depends on hand hygiene, safe water, sanitation, hygienic food preparation and storage, home hygiene, rapid treatment of cases, and public-health surveillance.
- Advise patients and caregivers to seek care if signs worsen or if household contacts develop bloody diarrhoea.
- Handover should include stool pattern, blood, fever, dehydration status, risk factors, culture/sensitivity results, antibiotic regimen and timing, response at 48 hours, nutrition plan, complications, IPC measures, and household/outbreak concerns.
Medicines in this guide
Oral rehydration salts = ORSRehydration according to dehydration severity and ongoing losses.Zinc sulfate oralAdjunct in children under 5 years.Ciprofloxacin oralFirst-line oral option when the strain is sensitive and oral treatment is possible.Ceftriaxone injectableParenteral option for severe infection, inability to take oral treatment, or pregnancy according to protocol.Azithromycin oralSecond-line option when ciprofloxacin is unsuitable or ineffective.Cefixime oralSecond-line oral alternative.Paracetamol = acetaminophen oralNon-opioid fever or pain treatment.Tinidazole oralUsed if second-line shigellosis treatment fails and amoebiasis is treated.Metronidazole oralAlternative amoebiasis treatment after failed shigellosis treatment when appropriate.
Source
MSF Clinical guidelines - Diagnosis and treatment manual (December 2024)
This page is a paraphrased clinician-oriented guide derived from the source topic on PDF page 116. Medicine-specific details should be checked against local protocol and the linked drug-information pages.