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Ohio State University Extension Fact Sheet

Family and Consumer Sciences

1787 Neil Avenue, Columbus, Ohio 43210-1295


An Infectious Foodborne Illness


Nancy Stehulak

What is shigella?

Shigella is a germ (one of the bacteria) that causes an infectious disease. This disease can be treated and most people get better quickly. One of the symptoms of Shigella poisoning is diarrhea. Severe diarrhea can cause dehydration for the very young, very old, or the chronically ill.

What are the symptoms?

The most common symptoms are diarrhea, fever, nausea, vomiting, stomach cramps, and straining to have a bowel movement. The stool 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 two to four days after the germs are swallowed. The symptoms usually last for several days, but can last for weeks.

How frequently do people get sick?

Approximately 300,000 cases of shigellosis occur annually in the United States. The number of cases connected to food is unknown, but it is probably substantial.

Do all infected people get sick?

No. Some only have mild symptoms and others do not get sick at all. Infants, the elderly, and the ill are capable of getting the most severe symptoms of the disease, but all persons are susceptible to some degree. Shigellosis is a very common illness suffered by individuals with acquired immune deficiency syndrome (AIDS) and AIDS related complex, as well as non-AIDS homosexual men.

How is shigella spread?

The germs must be swallowed to cause disease. They are often spread 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. They can also spread the germs to anyone or anything they touch, making others sick.

In rare cases, shigella germs also can be spread through ponds and swimming pools without enough chlorine. When people who have diarrhea swim in the pool or pond, the germs can live in the water and infect other swimmers who then swallow the water or even get their lips wet.

What foods are associated with shigella?

Salads, (potato, tuna, shrimp, macaroni, and chicken), raw vegetables, milk and dairy products, and poultry can carry shigella. Water contaminated with human waste and unsanitary handling by food handlers are the most common causes of contamination.

Is shigella spread by animals?

No. Common pets, farm animals, and wild animals cannot spread these germs; only monkeys and people can.

How can you know for sure if you have shigella?

Your doctor, nurse, or health center must send your stool sample to a laboratory. The laboratory then grows germs and tests them to see if any of the germs are shigella.

How is the disease treated?

Antibiotics are used to treat shigellosis. If you think you might have this disease, you should see your doctor or go to your health center. People with diarrhea or vomiting need extra fluids.

How can you prevent shigellosis?

Follow the tips below. As you make these 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.

Do not share food, drinks, spoons, or straws.

If you have a child in day-care who has diarrhea, tell the day-care providers. They can make sure the germs are not spread to other children.

Do not let anyone who has diarrhea use a pool or swim in a pond while they are sick. Be extra careful with small children, especially if they are in diapers.

If you or your child has 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 must report cases of shigellosis to the local health department. In order to protect the public, workers at food-related businesses who have shigellosis must stay out of work until they do not have diarrhea. A lab test on a stool sample must also show that there are no shigella germs. Workers in food-related businesses who have diarrhea and live with someone who has shigellosis must show that they have no shigella germs in their stool. Food-related businesses include restaurants, deli's, hospital kitchens, supermarkets, and dairy or food-processing plants. This law also includes workers in schools, residential programs, day-care, and health care facilities who feed, give mouth care, or dispense medications to clients.


  1. National Center for Disease Control, Center for Disease Control and Prevention, Food and Water Borne Bacterial Diseases, Atlanta, Georgia.

  2. U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, Foodborne Pathogenic Microorganisms and Natural Toxins Handbook, The Bad Bug Book.
  3. U.S. Food and Drug Administration, Morbidity and Mortality Weekly Report, 43 (35):1994.


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