- Causes Shigellosis. Faeco oral spread
- Tropical countries with poor hygiene
- Mental hospitals, residential schools, closed institutions.
- Spread is by unwashed hands after defecation
- Resistant to acid so less than 10 bacteria can cause disease
- Secrete a cytotoxin causing diarrhoea
- Gram-negative rods, invade colonic epithelium
- S. dysenteriae: Severe
- S. flexneri
- S. boydii
- S sonnei: Mild
Cases due to Shigella sonnei are mild. Sh. dysenteriae may be fulminating and
cause death within 48 hrs.
- Acute onset of watery diarrhoea with fever, abdominal pain and malaise
- There may be bloody diarrhoea, tenesmus and mucus
- Vomiting is seen in about one third. Usually, self-limiting
- Rectal prolapse, Megacolon, obstruction
- Reiter's syndrome (HLA-B27)
- Haemolytic uraemic syndrome
- Inflammatory bowel disease
- Causes of bloody diarrhoea
- Stool culture
- Sigmoidoscopy may be needed
- Grossly elevated WCC seen in some
- Hand-washing is important to prevent spread.
- Oral rehydration therapy. IV fluids if needed.
- Multi-resistant to antibiotics. Ciprofloxacin 500 mg bd may be used for 3 days.
- Caution with antimotility agents as they may prolong symptoms and infectivity