Shigellosis

Shigellosis is an infectious disease caused by a group of bacteria called Shigella. (Read about "Microorganisms") Shigellosis causes gastroenteritis, an inflammation of the gastrointestinal tract. (Read about "Gastroenteritis")

Most who are infected with Shigella develop diarrhea (Read about "Diarrhea"), fever and stomach cramps starting a day or two after they are exposed to the bacterium. The diarrhea is often bloody. The Centers for Disease Control and Prevention (CDC) says Shigellosis usually clears up in 5 to 7 days. In some people, especially young children and the elderly, the diarrhea can be so severe that the patient needs to be hospitalized. A severe infection with high fever may also be associated with seizures (Read about "Seizures") in children less than 2 years old. Some people who are infected may have no symptoms at all, but may still pass the Shigella bacteria to others. Infections in the digestive tract with Shigella may trigger reactive arthritis, a condition that can cause inflammation in the joints, and sometimes the eyes and/or urinary tract. (Read about "Reactive Arthritis")

As with any condition involving diarrhea, a big concern with Shigellosis, especially for children and seniors, is dehydration. (Read about "Dehydration") This happens if the body loses more fluids and salts (electrolytes) than it takes in. Signs of dehydration include a decrease in urine production (Read about "The Urinary System"), extreme thirst, dry mouth and unusual drowsiness. Severe dehydration is a medical emergency and requires immediate care. CDC says special oral rehydration fluids can be purchased at drugstores, and can be used according to the package directions. You should ask your pediatrician what's best in your child's case. If you have any concerns about dehydration, contact your doctor at once. It's also important to call your doctor if there is fever or prolonged vomiting.

There are several different kinds of Shigella bacteria:

• Shigella sonnei, also known as "group D" Shigella, accounts for over two-thirds of the shigellosis in the United States.
• Shigella flexneri or "group B" Shigella, accounts for almost all of the rest.

Other types of Shigella are rare in this country, though they continue to be important causes of disease in the developing world. One type found in the developing world, Shigella dysenteriae type 1, causes deadly epidemics.

Once someone has had shigellosis, they are not likely to get infected with that specific type again for at least several years, according to CDC. However, they can still get infected with other types of Shigella.

Every year, about 18,000 cases of shigellosis are reported in the United States. Because many milder cases are not diagnosed or reported, the actual number of infections may be twenty times greater.

The Shigella bacteria pass from one infected person to the next. Shigella are present in the diarrheal stools of infected persons while they are sick and for a week or two afterwards. Most Shigella infections are the result of the bacteria passing from stools or soiled fingers of one person to the mouth of another person. This happens when basic hygiene and hand washing habits are inadequate. It is particularly likely to occur among toddlers who are not fully toilet-trained. Family members and playmates of such children are at high risk of becoming infected.

Shigella infections may be acquired from eating contaminated food. (Read about "Food Safety") Contaminated food may look and smell normal. Food may become contaminated by infected food handlers who do not wash their hands with soap after using the bathroom. Vegetables can become contaminated if they are harvested from a field with sewage in it. Flies can breed in infected feces and then contaminate food. Shigella infections can also be acquired by drinking or swimming in contaminated water. Water may become contaminated if sewage runs into it, or if someone with shigellosis swims in it.

Related Information:

    Digestive System

    Travel and Health