Shigellosis

[Marquetta]

Shigellosis is infection by the gram-negative bacteria Shigella. It results in watery diarrhea or dysentery (the frequent and often painful passage of small amounts of stool that contains blood, pus, and mucus).

Shigella bacteria are excreted in stool and can be easily spread when hygiene or sanitation is inadequate.
People may have watery diarrhea, sometimes leading to severe dehydration.
Identifying the bacteria in a sample of stool can confirm the diagnosis.
For people with shigellosis and people who care for them, meticulous hygiene is necessary to avoid spreading the infection.
Fluids are given by mouth or, if the infection is severe, intravenously.
Antibiotics are used for people who have a severe infection or those who have a weakened immune system.

(See also Overview of Bacteria.)
Shigella bacteria are a common cause of dysentery in the United States and throughout the world.
Because stomach acid does not easily destroy these bacteria, ingesting even a small number of them causes infection. In the large intestine, the bacteria cause inflammation, and because they are then excreted in stool,

Infection spreads easily from person to person when hands are soiled.

Infection is also spread through the following:

Oral-anal sex
Food contaminated by infected food handlers who do not wash their hands with soap after using a toilet
Water contaminated with human waste
Swimming and wading pools that are inadequately chlorinated

Infection easily spreads among people who live together. Outbreaks also occur in places that are overcrowded and have inadequate sanitation, such as

Day-care centers for children
Long-term care facilities
Refugee camps
Institutions for the intellectually disabled
Cruise ships
Military camps
Developing countries

Children are more likely to become infected and to have severe symptoms, such as seizures.
There are four species of Shigella. All cause diarrhea. However, one—Shigella dysenteriae—is more likely to cause severe diarrhea, dysentery, and complications.