Shigella - Bacillary Dysentery

Symptoms: Shigella is an acute disease of the intestine characterised by diarrhoea, fever, stomach cramps and often vomiting. These symptoms usually occur 1 3 days after ingestion of the bacteria. Stools may contain blood, mucous and pus, and the illness can last for up to 2 weeks (usually 4 7 days). However you may be infectious for up to 4 weeks even if symptom free.

Where does it come from and how does it spread?

This particular illness can be caused by 4 different types of Shigella bacterium. In this country it is usually Shigella sonnei and less frequently Shigella flexneii. From abroad it may be Shigella dysenteriae or Shigella boydii. The severity of the illness depends on the type of Shigella causing the infection.
Man is the main reservoir of the bacteria which can be spread by the faecal oral route from an infected person, e.g. poor toilet facilities or practices, or by the consumption of contaminated foods e.g. water, milk, imported iceberg lettuce. The illness is more common and severe in children. However sporadic infections occur after travel to areas where hygiene is poor and overcrowding is common. Secondary infections in households due to person to person spread can be as high as 40%. Fatality is normally less than 1%.