Shigella is a bacteria that causes an infection called shigellosis.

What is Shigella?

According to the Centers for Disease Control and Prevention (CDC), Shigella bacteria cause approximately 450,000 infections every year in the United States. Shigella infections are typically the result of bacteria passing from feces (poop) or the contaminated hands of one person to the mouth of another person.¹

Symptoms

Symptoms of shigellosis usually start one to two days after exposure and last for seven days. Symptoms include the following: ¹

• Diarrhea; sometimes with blood or mucus
• Fever
• Stomach pain
• Feeling the need to pass feces (poop), even when bowels are empty

If you think you may have shigellosis, seek medical care and get tested. It may take some time for your body to recover—sometimes it can take several months for bowel movements to return to normal.¹

Transmission

Risk Factors

Shigella outbreaks can occur in any community, but some people are more likely to be exposed to Shigella than others. Additionally, some individuals are more likely to experience more severe illness when infected with Shigella. ^1,2

• Shigella infection is most common among children under 5. Children can get the infection by placing their unwashed hands in their mouth after touching something contaminated with Shigella. The illness can then spread among other children in school and childcare, and at home among family members. ^1,2
• People experiencing homelessness are also at high risk of becoming infected with Shigella. People living homeless are more likely to be exposed to contaminated food or water, live in overcrowded or contaminated living circumstances, and have less access to options for washing or sanitizing their hands. People experiencing homelessness may also be more likely to become infected or experience severe illness due to preexisting conditions and weakened immune systems. ^1,2
• People who travel to countries where sanitation and water treatment are poor may also be more likely to become infected. They may also be more likely to be infected with types of Shigella that are more severe and more difficult to treat.³ Travelers may encounter Shigella in food, drinking water, and recreational water (pools and natural swimming areas), on surfaces, and on people contaminated with Shigella. Travelers can protect their health by practicing safe eating and drinking habits while abroad and by washing their hands often or by using hand sanitizer that is at least 60% alcohol if soap and water are not available.^1,2
• Men who have sex with men are also more likely to be infected with Shigella. Shigella spreads from the feces of an infected person to the mouth of another person, including by touching contaminated hands or clothing, which can happen during sexual activity. For more information about outbreaks among men who have sex with men, please see Shigella Infection Among Gay, Bisexual, and Other Men Who Have Sex with Men.^1,2
• People with weakened immune systems are more likely to experience severe illness when infected with Shigella. This includes individuals with an illness like HIV and individuals who are receiving medical treatments that weaken their immune system, such as chemotherapy for cancer. In situations with severe illness, Shigella is more likely to spread to the blood, which can be life threatening.^1,2

Diagnosis

Shigella can be diagnosed using a laboratory test that detects the bacteria in a stool sample (a sample of feces collected from someone who is sick).^1,4

Treatment

Most people recover from shigellosis on their own within five to seven days. People with mild shigellosis can take the following steps to manage their symptoms:^1,4

• Rest
• Drink plenty of fluids to stay hydrated (diarrhea can cause dehydration)¹

Healthcare providers may prescribe antibiotics for severe cases of shigellosis; however, some antibiotics are not effective against certain types of Shigella. If your symptoms do not improve after a few days on antibiotics, contact your provider. Additional laboratory tests may be needed to make sure that the right antibiotics are prescribed for the type of Shigella infection.¹

An excerpt from SRHD’s Jan. 3, 2024, Facebook Live stream. Learn about Shigella, how to prevent infection, and get an overview of the 2023-2024 outbreak in Spokane County.

There are no vaccines to prevent infection with Shigella, but there are steps that people can take to avoid becoming infected with Shigella or prevent spreading it to others when sick.

Avoid Getting Sick

Wash your hands with soap and water for 20 seconds or use alcohol-based hand sanitizer that is at least 60% alcohol, rubbing your hands until dry. Make sure to clean under your fingernails.⁵

Wash your hands:

• After using the toilet and changing diapers (when possible, wash with soap and water)
• Before eating or preparing food
• Before and after engaging in sexual activity⁶

Other ways to avoid Shigella infection include the following:

• Avoid swallowing water that could be contaminated with Shigella, including lakes, ponds, hot tubs and swimming pools.
• While traveling internationally, wash your hands often and stick to safe eating and drinking habits.
• If a sexual partner has recently been infected with Shigella, avoid having sex, including vaginal, anal or oral sex for two weeks after your partner’s symptoms stop. Please note that it is possible for Shigella to be in feces for more than two weeks, especially in someone who had severe illness or who is immunocompromised. ⁶

If You Have Shigella

Shigella can be in feces for two weeks after symptoms end. People who are sick should wash their hands well and often to avoid reinfecting themselves or spreading Shigella to others. People with Shigella should also stay home from healthcare, food service, and childcare jobs until they have been cleared by public health to return to work, after testing negative for Shigella twice, 24 hours apart. ⁶

Take these precautions for two weeks after symptoms end:⁶

• Do not prepare food for others
• Do not engage in water recreation, such as swimming or sitting in hot tubs
• Do not have sex
• Do not share cigarettes, utensils, pipes, needles, tooters, straws, or other personal items

Disinfection

If you or someone in your household has Shigella, you can take additional steps to prevent Shigella from spreading on contaminated surfaces. Most disinfectants kill Shigella, and you should be able to check what germs a disinfectant kills on the product label. If you are unsure if a product kills Shigella, you can use bleach. For instructions on cleaning with bleach, please see “How to Use Bleach Safely” in the CDC’s Shigella Prevention and Control Toolkit.⁷

Disinfect the following surfaces often:

• High touch surfaces, like doorknobs, handles, and counters
• Tables and areas where people eat
• Where food is prepared