Shigellosis

Conditions Basics

What is shigellosis?

Shigellosis is a type of food poisoning caused by infection with the Shigella bacterium. It is more common in summer than winter. Children ages 2 to 4 are most likely to get the condition.

What causes it?

Shigellosis is spread when the bacteria in feces (stool) or on soiled fingers are ingested. Poor hand-washing habits and eating contaminated food may cause the condition. Shigellosis is often found in day care centers, nursing homes, refugee camps, and other places where conditions are crowded and sanitation is poor.

• Shigellosis is likely to occur among toddlers who are not fully toilet trained. Family members and playmates of infected children are also at high risk of becoming infected.
• Food may become contaminated by infected food handlers who do not wash their hands with soap after using the bathroom.
• Vegetables can be contaminated if they are harvested from a field that has sewage in it. Also, flies can breed in infected feces and then contaminate food.
• Shigellosis can result from drinking or swimming in contaminated water. Water may become contaminated if sewage runs into it or if someone with shigellosis swims in it.
• Shigellosis also can be spread through sex, especially through anal and oral sex.

What are the symptoms?

The symptoms of shigellosis include diarrhea (often bloody), fever, and stomach cramps starting 1 or 2 days after you are exposed to the bacteria. Shigellosis usually lasts 5 to 7 days. In some people, especially young children and older adults, the diarrhea can be so severe that a hospital stay is needed. Some people who are infected may have no symptoms at all but may still spread shigellosis to others.

How is it diagnosed?

Because many different diseases can cause a fever and bloody diarrhea, lab tests are the best way to diagnose shigellosis. Your doctor will most likely still do a physical exam and ask you questions about your symptoms, foods you have recently eaten, and your work and home environments. A stool culture confirms the diagnosis. Blood tests may be done if your symptoms are severe or to rule out other causes.

How is shigellosis treated?

Shigellosis is usually treated with antibiotics. But some types of Shigella bacteria are not killed by antibiotics. This is called resistance. Because using antibiotics can make these bacteria even more resistant, mild cases of shigellosis are often not treated with antibiotics. In this case, shigellosis is treated by managing complications until it passes. Dehydration caused by diarrhea is the most common complication. Do not use medicines to prevent diarrhea.

To prevent dehydration, take frequent sips of a rehydration drink (such as Pedialyte). Soda and fruit juices have too much sugar and not enough of the important electrolytes that are lost during diarrhea. These kinds of drinks should not be used to rehydrate.

When you feel like eating, start with small amounts of food. This will help you get enough nutrition.

Complications

After shigellosis, it may take months before your bowel movements are completely normal again. But people with diarrhea usually recover completely.

A small number of people who are infected with one type of shigella bacteria, Shigella flexneri, will later develop pain in their joints, irritation of the eyes, and painful urination. This is called reactive arthritis. It can last for months or years and can lead to chronic arthritis.

How can you prevent it?

You can help prevent the spread of shigellosis by washing your hands frequently and carefully with soap, especially if you work or spend time in day care centers or with children who are not completely toilet trained. When possible, keep young children with shigellosis who are still in diapers away from uninfected children.

If your child is in diapers and has shigellosis, after diaper changing, wipe the changing area with a disinfectant such as diluted household bleach and put the diapers in a closed-lid garbage can. Then wash your hands with soap and warm water. To dilute household bleach, follow the directions on the label.

People who have shigellosis should not prepare food or pour water for others. Shigella are present in the diarrhea of people with shigellosis and for 1 or 2 weeks after symptoms have stopped.