Definition of Shigellosis:

Shigellosis is an acute bacterial infection of the lining of the intestines.

Causes, incidence, and risk factors:

Shigellosis is caused by a group of bacteria called Shigella.

There are several types of Shigella.

• Shigella sonnei, also called "group D" Shigella, is responsible for most cases of shigellosis in the United States.
• Shigella flexneri, or "group B" Shigella, cause almost all other cases.
• Shigella dysenteriae type 1 is rare in the U.S. but can lead to deadly outbreaks in developing countries.

People infected with the bacteria release it into their stool. The bacteria can spread from an infected person to contaminate water or food, or directly to another person. Getting just a little bit of the Shigella bacteria into your mouth is enough to cause symptoms.

Outbreaks of shigellosis are associated with poor sanitation, contaminated food and water, and crowded living conditions.

Shigellosis is common among travelers in developing countries and workers or residents of refugee camps.

There are about 18,000 cases of shigellosis per year in the United States. The condition is most commonly seen in day care centers and similar places.