Shigella is a group of bacteria that can cause an infectious disease involving diarrhea, fever, and stomach cramps starting a day or two after exposure. The bacteria causes about 500,000 cases of diarrhea in the United States annually . In persons with healthy immune systems, symptoms usually last about 5 to 7 days. Persons with diarrhea usually recover completely, although it may be several months before their bowel habits are entirely normal. Once someone has had shigellosis, they are not likely to get infected with that specific type again for at least several years. However, they can still get infected with other types of Shigella.
Shigella germs are present in the stools of infected persons while they have diarrhea and for up to a week or two after the diarrhea has gone away. Shigella is very contagious; exposure to even a tiny amount of contaminated fecal matter—too small to see– can cause infection. Transmission of Shigella occurs when people put something in their mouths or swallow something that has come into contact with stool of a person infected with Shigella. This can happen when:
- Contaminated hands touch your food or mouth. Hands can become contaminated through a variety of activities, such as touching surfaces (e.g., toys, bathroom fixtures, changing tables, diaper pails) that have been contaminated by stool from an infected person. Hands can also become contaminated with Shigella while changing the diaper of an infected child or caring for an infected person.
- Eating food contaminated with Shigella. Food may become contaminated if food handlers have shigellosis. Produce can become contaminated if growing fields contain human sewage. Flies can breed in infected feces and then contaminate food when they land on it.
- Swallowing recreational (for example lake or river water while swimming) or drinking water that was contaminated by infected fecal matter.
- Exposure to feces through sexual contact.
Many different kinds of germs can cause diarrhea, so establishing the cause will help guide treatment. Healthcare providers can order laboratory tests to identify Shigella in the stools of an infected person. The laboratory can also do special tests to determine which antibiotics, if any, would be best to treat the infection.
Diarrhea caused by Shigella usually resolves without antibiotic treatment in 5 to 7 days. People with mild shigellosis may need only fluids and rest. Bismuth subsalicylate (e.g., Pepto-Bismol®) may be helpful , but medications that cause the gut to slow down, such as loperamide (e.g., Imodium®) or diphenoxylate with atropine (e.g., Lomotil®), should be avoided. Antibiotics are useful for severe cases of shigellosis because they can reduce the duration of symptoms. However, Shigella is often resistant to antibiotics. If you require antibiotic treatment for shigellosis, your healthcare provider can culture your stool and determine which antibiotics are likely to work. Tell your healthcare provider if you do not get better within a couple of days after starting antibiotics. He or she can do additional tests to learn whether your strain of Shigella is resistant to the antibiotic you are taking.
Currently, there is no vaccine to prevent shigellosis. However, you can reduce your risk of getting shigellosis by:
- Carefully washing your hands with soap during key times:
- Before eating.
- After changing a diaper or helping to clean another person who has defecated (pooped).
- If you care for a child in diapers who has shigellosis, promptly discard the soiled diapers in a lidded, lined garbage can, and wash your hands and the child’s hands carefully with soap and water immediately after changing the diapers. Any leaks or spills of diaper contents should be cleaned up immediately.
- Avoid swallowing water from ponds, lakes, or untreated swimming pools.
- When traveling internationally, follow food and water precautions strictly and wash hands with soap frequently.
- Avoid sexual activity with those who have diarrhea or who recently recovered from diarrhea.
Childcare centers can take the following steps to prevent spread of shigellosis:
- Exclude any child with diarrhea from the childcare setting until the diarrhea has stopped.
- Children who have recently recovered from shigellosis can be grouped together in one classroom (cohorted) to minimize exposing uninfected children and staff to Shigella.
- Assign separate staff to change diapers and prepare or serve food.
- Reassign adults with diarrhea to jobs that minimize opportunities for spreading infection (for example, administrative work instead of food preparation).