Shigellosis


– Shigellosis is a highly contagious bacterial infection resulting in bloody diarrhoea. There are 4 serogroups of shigella: S. dysenteriaeS. sonneiS. flexneriS. boydii.
– S. dysenteriae type 1 (Sd1) is the only strain that causes large scale outbreaks. It has the highest case fatality rate (up to 10%). 
– Patients at risk of death are children under 5 years, malnourished patients, children after measles, adults over 50 years.

Clinical features

– Diarrhoea with bright red blood visible in stool1 , with or without fever 
– Abdominal and rectal pain frequent
– Signs of serious illness: fever above 39 °C; severe dehydration; seizures, altered mental status
– Complications (more frequent with Sd1): febrile seizures (5 to 30% of children), rectal prolapse (3%), septicaemia, intestinal obstruction or perforation, moderate to severe haemolytic uraemic syndrome

Laboratory

Shigellosis in an epidemic context:
– Confirm the causal agent (stool culture) and perform antibiotic sensitivity tests.
– Perform monthly culture and sensitivity tests (antibiotic resistance can develop rapidly, sometimes during the course of an outbreak).

Treatment

– Patients with signs of serious illness or with life-threatening risk factors must be admitted as inpatients.
– Treat patients with neither signs of serious illness nor risk factors as outpatients.
– Antibiotherapy:

First-line treatment

ciprofloxacin PO for 3 days
Children: 15 mg/kg 2 times daily (max. 1 g daily)
Adults: 500 mg 2 times daily

• if the strain is sensitive
• if there is no antibiotic sensitivity test
• if oral administration is possible

ceftriaxone IM for 3 days
Children: 50 to 100 mg/kg once daily (max. 1 g daily)
Adults: 1 to 2 g once daily

• in patients with severe infection and/or oral administration is not possible
• in pregnant women2

If resistance or contra-indication to ciprofloxacin or if no improvement within 48 hours of starting first-line treatment:
azithromycin PO for 5 days
Children: one dose of 12 mg/kg on D1 then 6 mg/kg once daily from D2 to D5
Adults: one dose of 500 mg on D1 then 250 mg once daily from D2 to D5
or
cefixime PO for 5 days
Children: 8 mg/kg once daily (max. 400 mg daily)
Adults: 400 mg once daily
If there is no improvement 48 hours after starting second-line treatment, treat for amoebiasis.1,2

– For pain and/or fever:
paracetamol PO (see Pain, Chapter 1). All opioid analgesics are contra-indicated as they slow peristalsis.

– Supportive therapy:
• nutrition: nutritional supplement with frequent meals 
+ 2500 kcal daily during hospitalisation 
+ 1000 kcal daily as outpatients 
• rehydration: systematic administration of ORS according to WHO protocols (Appendix 2).
• zinc supplement in children under 5 years (see Acute diarrhoea).

– Never give loperamide or any other antidiarrhoeal.

– Management of complications: rectal prolapse reduction, septicaemia (see Septic shock, Chapter 1), etc.

Shigellosis in an epidemic context 

– Isolation of hospitalised patients; school exclusion of children treated as outpatients.
– Hygiene (handwashing, hygienic preparation and storage of food, home hygiene, etc.).
– Management if signs worsen or bloody diarrhoea in entourage (seek medical attention).



Footnotes
Ref Notes
1 This definition excludes: blood detected on microscope examination; stool containing digested blood (melaena); streaks of blood on the surface of normal stool (haemorrhoids, anal or rectal lesion, etc.).
2 Ciprofloxacin should be avoided in pregnant women. Nevertheless, if ceftriaxone is not available, the other antibiotics can be used, including ciprofloxacin if necessary.


References

  1. Karen L. Kotloff et al. Seminar: Shigellosis. The Lancet, Volume 391, ISSUE 10122, P801-812, February 24, 2018.

  2. Word Health Organization. Pocket book for hospital care in children: guidelines for the management of common childhood illnesses, 2013.
    http://apps.who.int/iris/bitstream/handle/10665/81170/9789241548373_eng.pdf;jsessionid=CE5C46916607EF413AA9FCA89B84163F?sequence=1 [Accessed 20 September 2018]