Shigellosis is caused by Shigella bacteria. There are four groups of Shigella that cause infection in humans: Shigella sonnei, S. dysenteriae, S. flexneri, and S. boydii. S. sonnei is the most common type of Shigella in developed countries, including the United States. Outbreaks of shigellosis frequently occur in tropical or temperate climates, especially in areas with severe crowding or poor hygiene. Outbreaks sometimes occur in daycare and institutional settings.
Last Updated January 06, 2012