Shigellosis Foodborne Disease: What You Should Know

Preventable With Good Hygiene


We’ve all seen the signs in restaurant bathrooms stating: “Employees must wash their hands before returning to work.” Shigellosis, a diarrheal disease caused by bacteria, is one of several infections that can be easily prevented with good hygiene and frequent hand washing.

Species Names

Shigella sonnei, Shigella flexneri, Shigella boydii, Shigella dysenteriae

Type of Microbe

Gram-negative bacteria

How It Spreads

Shigellosis is spread by person-to-person through the fecal-oral route (or ingestion of contaminated material after a bowel movement).

It has been involved in several food-borne outbreaks. Food handlers who have poor hygiene, such as those who haven't washed off the bacteria completely after a toilet break, can spread the disease. It can also be spread through flies, swimming pools, and anal contact during sex.

Who’s at Risk?

All people are at risk. Most cases are in small preschool-aged children, especially those who attend daycare centers. It is more common in the summer and fall seasons. According to the Centers for Disease Control and Prevention, about 14,000 cases of Shigellosis are reported annually in the United States. There are likely many unreported cases. Including unreported cases, there are likely 300,000 cases each year. In developing countries, the disease rates can be higher and the disease can be fatal.

Who's at More Risk? 

There are also cases of Drug Resistant Shigella that are causing concern. These strains are often resistant to Cipro (Ciprofloxacin) a common antibiotic.

There is also Azithro-resistant Shigella. These strains can be found in travelers returning to the US from trips abroad. About half of drug resistant infections are found among returning travelers. Most travel is to Southeast Asia. Taking antibiotics to prevent traveler's diarrhea can increase the chance of bringing home drug resistant bacteria (though not necessarily Shigella).

There are also cases that have spread among gay/bi males and men who have sex with men (MSM).


Acute symptoms include fever, severe lower abdominal pain, and bloody diarrhea with mucus.


Gram-stain and culture of stool.


Usually goes away within 5 to 7 days; hospitalization is rare.


Usually not necessary, but antibiotics can shorten the illness. Anti-diarrheal drugs should be avoided since they prevent the microbe from leaving the body and can make people sicker. Please keep yourself hydrated. If you, a child, or anyone else is becoming dehydrated, you can call a health professional. You may need to drink fluids that can rehydrate you with some sugar and a bit of salt.


Hand washing and good hygiene among adults and children are very important. It is crucial that hands and food are washed in clean water. This relies on there being functioning sanitation systems. There is no vaccine available. It is important to follow hygiene techniques after changing kids' diapers and after using the bathroom.

How It Causes Disease

Ingestion of shigella results in an invasion of the bacteria into the lining of the small intestine, where it multiplies. Symptoms usually don't begin for 12–96 hours after being exposed to the bacteria. After 2 to 7 days, the bacteria invade the large intestine. Some species produce a “Shiga toxin” that causes inflammation and secretion of intestinal fluids. The toxin also damages the tissue lining of the large intestine and kidney.


Once infected, it is unlikely to get infected with the same type of Shigella, due to the antibody immune response. However, infection by other types is still possible.


The infection can cause dehydration. If the toxin damages the kidney, it may lead to hemolytic uremic syndrome. About 2 percent of people with Shigella flexneri develop “post-infectious arthritis”, with symptoms including joint pain, eye irritation, and painful urination. You should talk to your doctor or nurse about avoiding any of these more serious problems. An illness that leaves you sick for a while can lead to other health problems, so it's important to talk to a health professional about any questions.

In other words, washing your hands (and food) in clean water is incredibly important. You don't want anything that should be down the toilet contaminating what you eat.


Shigella spp. FDA Bad Bug Book. Foodborne Pathogenic Microorganisms and Natural Toxins Handbook.

Shigellosis General Information. CDC DFBMD.

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