Epidemiology of Infectious Diseases: Shigellosis
Acute bacterial illness caused by four species of Shigella: dysenteriae, flexneri, boydii and sonnei1.
Shigella sonnei is the most common species in Western Europe and causes a relatively mild illness2.
Common clinical features
Watery or bloody diarrhoea, abdominal pain, fever and malaise.
S. boydii and S. dysenteriae, and most S. flexneri infections, originate outside the UK and present clinically as dysentery (diarrhoea with blood, mucus, and pus).
S. dysenteriae may be associated with serious disease, including toxic megacolon and the haemolytic uraemic syndrome (HPA).
Worldwide shigellosis causes an estimated 600,000 deaths per year, the majority in young children.
In the UK Shigella infection has decreased dramatically since the peak incidence period of 1950-1969 when 20,000 - 40,000 cases were reported each year (HPA) .
Mode of transmission
- Person to person via the faecal-oral route.
- From contaminated food or water.
1-3 days with a range of 12-96 hours, and up to 1 week for S. dysenteriae type 1.
Period of Communicability
As long as organism is excreted in the stool, usually within 4 weeks after illness.
Prevention and control
- Follow correct food hygiene practices for food preparation and cooking in domestic and commercial kitchens as described by the WHO Five keys to safer food1.
- World Health Organization: 5 Keys to Safer Food. Available at http://www.who.int/foodsafety/publications/consumer/5keys/en/
- Hawker J, Begg N, Blair I, Reintjes R, Weinberg J. Communicable Disease Control Handbook, Blackwell, 2005
© CM Kirwan 2006