Fact sheet about Shigella

What is Shigella?

Shigella is a germ (bacterium) that causes an infectious disease (called “shigellosis” or “dysentery”) of the bowel. This disease can be treated and most people get better fairly quickly. However, severe diarrhea can cause dehydration that can be dangerous for the very young, very old or the chronically ill. In rare cases, the germ can cause problems in other parts of the body.

What are the symptoms of shigellosis?

The most common symptoms are diarrhea, fever, nausea, vomiting, stomach cramps, and straining to have a bowel movement. The stool (feces) may contain blood, mucus or pus. In rare cases, young children with the disease can have seizures. Symptoms can take as long as a week to show up, but most often begin one to four days after the germs are swallowed. The symptoms usually last for several days, but can last for weeks.

How is Shigella spread?

Shigella is very easily spread as it takes very few organisms to make someone ill, but the germs must be swallowed to cause disease. This usually happens when people do not wash their hands with soap and water after using the toilet or changing a diaper. People who get the germs on their hands can infect themselves by eating, smoking, or touching their mouths. Infection can also happen during sexual activity. People with shigellosis can spread the germs to anyone or anything they touch, including food, which if not cooked properly can make others sick.

People can also get shigellosis from water. Lakes and ponds can become contaminated with the bacteria if sewage runs into them or if someone with shigellosis swims in or plays in the water. This can also happen in untreated wading pools or splash fountains, and swimming pools without enough chlorine. The bacteria can live in the water and infect people who swallow the water or just get their lips wet while swimming or playing.

Can Shigella be spread by animals?

No. Common pets, farm animals, and wild animals cannot spread these germs.

How is shigellosis diagnosed?

Your doctor, nurse or health center must send your stool sample or rectal swab to a laboratory. The laboratory then grows germs and tests them to see if any of the germs are Shigella. It takes the lab a few days to grow enough germs to test.

How is shigellosis treated?

People with mild infections usually get better without antibiotic treatment. However, antibiotics can shorten how long people are sick and are almost always given to people who have severe disease, bloody diarrhea or compromised immune systems. If you think you might have this disease, you should see your doctor or health care provider as soon as you can. People with diarrhea or vomiting may need extra fluids.

How can you prevent shigellosis?

The two most important things to remember are that Shigella can only make you sick if you swallow it and that soap and water will get rid of the germ on your hands. Follow the tips below; if you make them your habits, you can prevent shigellosis—as well as other diseases.

  • Always wash your hands thoroughly with soap and water before eating or touching food and after using the toilet or changing diapers
  • If you are taking care of someone with diarrhea, scrub your hands with plenty of soap and water after cleaning the bathroom, helping the person use the toilet, or changing diapers, soiled clothes or soiled sheets.
  • Don't share food, drinks, spoons or straws.
  • If you have a child in day-care who has diarrhea, tell the day-care providers so they can make sure the germs are not spread to other children.
  • Don’t let anyone who has diarrhea use a pool, play in fountains, or swim in a pond while they are still sick. Be extra careful with small children, even if they are in diapers.

If you or your child have persistent diarrhea (with or without a fever), or if the diarrhea is very bad, call your doctor or health center for advice.

Are there any health regulations for people with shigellosis?

Yes. Because shigellosis is a disease that can easily spread to other people, health care providers are required by law to report cases of shigellosis to the local board of health.

In order to protect the public, workers at food-related businesses who have shigellosis must stay out of work until they don’t have diarrhea and lab tests on two different stool samples show that there are no shigella germs. Workers in food-related businesses who have diarrhea and live with someone who has shigellosis must also show that they have no shigella germs in their stool. Food-related businesses include restaurants, sandwich shops, hospital kitchens, supermarkets, dairy or food-processing plants. This also includes workers in schools, residential programs, day-care and health care facilities, who feed, give mouth care or dispense medications to clients.

Where can I get more information?

  • Your doctor, nurse or clinic
  • The Centers for Disease Control and Prevention (CDC) website
  • Your local board of health (listed in the telephone directory under “government”)
  • The Massachusetts Department of Public Health (MDPH), Division of Epidemiology and Immunization at (617) 983-6800 or toll-free at (888) 658-2850

Spanish and Portuguese translations of this fact sheet are available under additional resources.

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