Shigellosis management

Definition

Shigellosis is an acute intestinal infection caused by Shigella species, which are gram-negative facultative intracellular bacterial pathogens.

The four major species are:

• Shigella dysenteriae (Group A)

• Shigella flexneri (Group B)

• Shigella boydii (Group C)

• Shigella sonnei (Group D)

Transmission occurs through the faecal-oral route, typically by ingestion of contaminated food or water. The disease commonly results in bacillary dysentery.

Clinical presentation

• Acute abdominal cramping

• High-grade fever

• Vomiting (emesis)

• Large-volume watery diarrhoea

• Tenesmus

• Urgency

• Faecal incontinence

• Mucoid bloody diarrhoea

• Severe headache

• Lethargy

• Meningismus

• Delirium

• Convulsions

• Profound dehydration

• Hypoglycaemia

Severe complications

• Hemolytic uremic syndrome (HUS)

• Microangiopathic hemolytic anaemia

• Thrombocytopenia

• Acute renal failure

Investigations

Microbiological diagnosis

• Isolation of Shigella organisms from:

  • Stool specimens

  • Rectal swab specimens

Culture

• Stool culture for suspected cases, especially during the early course of infection

Toxin detection

• ELISA for Shiga toxin detection in stool specimens, particularly for Shigella dysenteriae type I

Pharmacological treatment

Ciprofloxacin

• Dose: 500 mg

• Route: Oral (PO)

• Frequency: Every 12 hours

• Duration: 5 days

OR

Erythromycin

• Dose: 500 mg

• Route: Oral (PO)

• Frequency: Every 6 hours

• Duration: 5 days

Monitoring

• Monitor hydration status

• Monitor stool frequency and severity

• Monitor for signs of dehydration

• Monitor renal function in severe disease

• Monitor for neurological complications

• Monitor for development of hemolytic uremic syndrome

Possible complications

• Bacillary dysentery

• Profound dehydration

• Hypoglycaemia

• Convulsions

• Delirium

• Hemolytic uremic syndrome

• Microangiopathic hemolytic anaemia

• Thrombocytopenia

• Acute renal failure

Follow-up

• Reassess symptoms after completion of treatment.

• Evaluate for persistent diarrhoea or ongoing dehydration.

• Investigate for complications if symptoms worsen or fail to improve.