Questions & Answers
Shigellosis is a diarrheal disease caused by a group of bacteria called Shigella. Shigella causes about 450,000 cases of diarrhea in the United States annually 1. There are four different species of Shigella:
- Shigella sonnei (the most common species in the United States)
- Shigella flexneri
- Shigella boydii
- Shigella dysenteriae
S. dysenteriae and S. boydii are rare in the United States, though they continue to be important causes of disease in the developing world. Shigella dysenteriae type 1 can be deadly 2.
- CDC. Antibiotic Resistance Threats in the United States, 2019. Atlanta, GA: U.S. Department of Health and Human Services, CDC; 2019.
- American Academy of Pediatrics. Red Book: Report of the Committee on Infectious Diseases. 2012. 645-647.
Shigella germs are in the stool (poop) of sick people while they have diarrhea and for up to a week or two after the diarrhea has gone away. Shigella germs are very contagious; it takes just a small number of Shigella germs to make someone sick. People can get shigellosis when they put something in their mouths or swallow something that has come into contact with the stool of someone else who is sick with shigellosis. People could get sick by:
- Getting Shigella germs on their hands and then touching your food or mouth. You can get Shigella germs on your hands after:
- Touching surfaces contaminated with germs from stool from a sick person, such as toys, bathroom fixtures, changing tables or diaper pails
- Changing the diaper of a sick child or caring for a sick person
- Eating food that was prepared by someone who is sick with shigellosis
- Swallowing recreational water (for example, lake or river water) while swimming or drinking water that is contaminated with stool (poop) containing the germ
- Having exposure to stool during sexual contact with someone who is sick or recently (several weeks) recovered from shigellosis.
Symptoms of shigellosis typically start 1–2 days after exposure to the germ and include:
- Diarrhea (sometimes bloody)
- Stomach pain
- Feeling the need to pass stool [poop] even when the bowels are empty
For most people, symptoms usually last about 5 to 7 days. In some cases, it may take several months before bowel habits (for example, how often someone passes stool and the consistency of their stool) are entirely normal.
- Young children are the most likely to get shigellosis, but people of all ages are affected 1. Many outbreaks are related to childcare settings and schools, and illness commonly spreads from young children to their family members and others in their communities because it is so contagious.
- Travelers to developing countries may be more likely to get shigellosis, and to become infected with strains of Shigella bacteria that are resistant to important antibiotics 2-3. Travelers may be exposed through contaminated food, water (both drinking and recreational water), or surfaces. Travelers can protect themselves by strictly following food and water precautions, and washing hands with soap frequently. For more information, see Travelers’ Health – Food and Water Safety.
- Gay and bisexual men and other men who have sex with men (MSM)† are more likely to acquire shigellosis than the general adult population 4. Shigella passes from feces or soiled fingers of one person to the mouth of another person, which can happen during sexual activity. Many shigellosis outbreaks among MSM have been reported in the United States, Canada, Japan, and Europe since 1999 5-11. For more information, see Shigella Infections Among Gay & Bisexual Men.
- People who have weakened immune systems due to illness (such as HIV) or medical treatment (such as chemotherapy for cancer) can get a more serious illness. A severe shigellosis may involve the infection spreading into the blood, which can be life-threatening 12.
- Large outbreaks of shigellosis often start in childcare settings and spread among small social groups such as in traditionally observant Jewish communities 13-15. Similar outbreaks could occur among any race, ethnicity or community social circle because Shigella germs can spread easily from one person to another.
† The term “men who have sex with men”is used in CDC surveillance systems because it indicates men who engage in behaviors that may transmit Shigella infection, rather than how someone identifies their sexuality.
- Adams DA, Thomas KR, Jajosky RA, Foster L, Baroi G, Sharp P, Onweh DH, Schley AW, Anderson WJ, Nationally Notifiable Infectious Conditions Group. Summary of Notifiable Infectious Diseases and Conditions – United States, 2015. MMWR Morb Mortal Wkly Rep. 2017;64(53):1-143.
- Kantele A. As far as travelers’ risk of acquiring resistant intestinal microbes is considered, no antibiotics (absorbable or nonabsorbable) are safe.external icon Clin Infect Dis. 2015.
- O’Donnell AT, Vieira AR, Huang JY,Whichard J, Cole D, Karp BE. Quinolone-resistant Salmonella enterica serotype Enteritidis infections associated with international travelexternal icon. Clin Infect Dis. 2014;59(9):e139-41.
- Aragon TJ, Vugia DJ, Shallow S, Samuel MC, Reingold A, Angulo FJ, Bradford WZ. Case-control study of shigellosis in San Francisco: the role of sexual transmission and HIV infectionexternal icon Clin Infect Dis. 2007;44(3):327-34.
- Heiman KE, Karlsson M, Grass J, Howie B, Kirkcaldy RD, Mahon B, Brooks JT, Bowen A. Notes from the field: Shigella with decreased susceptibility to azithromycin among men who have sex with men – United States, 2002-2013. MMWR Morb Mortal Wkly Rep. 2014;63(6):132-3.
- Gaudreau C, Barkati S, Leduc JM, Pilon PA, Favreau J, Bekal S. Shigella spp. with reduced azithromycin susceptibility, Quebec, Canada, 2012-2013. Emerg Infect Dis. 2014;20(5):854-6.
- Gaudreau C, Ratnayake R, Pilon PA, Gagnon S, Roger M, Levesque S. Ciprofloxacin-resistant Shigella sonnei among men who have sex with men, Canada, 2010. Emerg Infect Dis. 2011;17(9):1747-50.
- Morgan O, Crook P, Cheasty T, Jiggle B, Giraudon I, Hughes H, Jones SM. Shigella sonnei outbreak among homosexual men, London. Emerg Infect Dis. 2006;12(9):1458-60.
- Okame M, Adachi E, Sato H, Shimizu S, Kikuchi T, Miyazaki N, Koga M, Nakamura H, Suzuki M, Oyaizu N, Fujii T, Iwamoto A, Koibuchi T. Shigella sonnei outbreak among men who have sex with men in Tokyoexternal icon. Jpn J Infect Dis. 2012;65(3):277-8.
- Watson, JT, Jones RC, Fernandez J, Cortes C, Gerber SI, Kuo KJ, Price JS, Brooks JT, Jennings D, Fair M, Mintz E, Bowen A. Shigella flexneri serotype 3 infections among men who have sex with men–Chicago, Illinois, 2003-2004. pdf icon[PDF – 24 pages] MMWR Morb Mortal Wkly Rep. 2005;54(33):820-2.
- Bowen A, Eikmeier D, Talley P, Siston A, Smith S, Hurd J, Smith K, Leano F, Bicknese A, Norton C, Campbell D. Notes from the Field: Outbreaks of Shigella sonnei infection with decreased susceptibility to azithromycin among men who have sex with men — Chicago and Metropolitan Minneapolis-St. Paul, 2014. MMWR Morb Mortal Wkly Rep. 2015;64(21):597-8.
- HHS. Guidelines for the prevention and treatment of opportunistic infections in HIV-infected adults and adolescents: recommendations from the Centers for Disease Control and Prevention, the National Institutes of Health, and the HIV Medicine Association of the Infectious Diseases Society of America. pdf icon[PDF – 425 pages]external icon Panel on Opportunistic Infections in HIV-Infected Adults and Adolescents. 2015.
- De Schrijver K, Bertrand S, Gutierrez Garitano I, Van den Branden D, Van Schaeren J. Outbreak of Shigella sonnei infections in the Orthodox Jewish community of Antwerp, Belgium, April to August 2008.external icon Euro Surveill. 2011;16(14).
- Garrett V, Bornschlegel K, Lange D, Reddy V, Kornstein L, Kornblum J, Agasan A, Hoekstra M, Layton M, Sobel J. A recurring outbreak of Shigella sonnei among traditionally observant Jewish children in New York City: the risks of daycare and household transmission.external icon Epidemiol Infect. 2006;134(6):1231-6.
- Sobel J, Cameron DN, Ismail J, Strockbine N, Williams M, Diaz PS, Westley B, Rittmann M, DiCristina J, Ragazzoni H, Tauxe RV, Mintz ED. A prolonged outbreak of Shigella sonnei infections in traditionally observant Jewish communities in North America caused by a molecularly distinct bacterial subtypeexternal icon. J Infect Dis. 1998;177(5):1405-9.
Many kinds of germs can cause diarrhea. Knowing which germ is causing an illness is important to help guide appropriate treatment. Healthcare providers can order laboratory tests to identify Shigella germs in the stool of an infected person.
People who have shigellosis usually get better without antibiotic treatment in 5 to 7 days. People with mild shigellosis may need only fluids and rest. Bismuth subsalicylate (for example, Pepto-Bismol) may be helpful 1,2, but people sick with shigellosis should not use medications that cause the gut to slow down and interfere with the way the body digests food, such as loperamide (for example, Imodium) or diphenoxylate with atropine (for example, Lomotil) 3.
Healthcare providers may prescribe antibiotics for people with severe cases of shigellosis to help them get better faster. However, some antibiotics are not effective against certain types of Shigella. Healthcare providers can order laboratory tests to determine which antibiotics are likely to work. Tell your healthcare provider if you do not get better within a couple of days after starting antibiotics. They can do more tests to learn whether your type of Shigella bacteria can be treated effectively with the antibiotic you are taking. If not, your doctor may prescribe another type of antibiotic.
- Pathophysiology of gastrointestinal infections: the role of bismuth subsalicylate. Scottsdale, Arizona, 11-14 February 1988. Proceedings. Rev Infect Dis. 1990;12 Suppl 1:S1-119.
- Steffen R. Worldwide efficacy of bismuth subsalicylate in the treatment of travelers' diarrhea. Rev Infect Dis. 1990;12 Suppl 1:S80-6.
- DuPont HL, Hornick RB. Adverse effect of lomotil therapy in shigellosis.external icon 1973;226(13):1525-8.
You can reduce your chance of getting sick from Shigella by taking these steps:
- Carefully washing your hands with soap and water during key times:
- Before preparing food and eating.
- After changing a diaper or helping to clean another person who has defecated (pooped).
- If you care for a child in diapers who has shigellosis, promptly throw away the soiled diapers in a covered, lined garbage can. Wash your hands and the child’s hands carefully with soap and water right after changing the diapers. Clean up any leaks or spills of diaper contents immediately.
- Avoid swallowing water from ponds, lakes, or untreated swimming pools.
- When traveling internationally, stick to safe eating and drinking habits, and wash hands often with soap and water. For more information, see Travelers' Health - Food and Water Safety.
- Avoid having sex (vaginal, anal, and oral) for one week after your partner recovers from diarrhea. Because Shigella germs may be in stool for several weeks, follow safe sexual practices, or ideally avoid having sex, for several weeks after your partner has recovered.
- Wash your hands carefully and frequently with soap and water, especially after using the bathroom.
- Do not prepare food for others while you are sick. After you get better, wash your hands carefully with soap and water before preparing food for others.
- Stay home from childcare, school and food service facilities while sick. Your local health department may have a policy on when to return to childcare or school. Refer to your local health department website for more information.
- Avoid swimming until you have fully recovered.
- Wait to have sex (vaginal, anal, and oral) for one week after you no longer have diarrhea. Because Shigella germs may be in stool for several weeks, follow safe sexual practices, or ideally avoid having sex, for several weeks after you have recovered.
- Supervise handwashing of toddlers and small children after they use the bathroom. Wash your hands and your infant’s hands with soap and water after diaper changes.
- Throw away soiled diapers in a covered, lined garbage can. Clean diaper changing areas after using them. (Safe & Healthy Diapering in the Home)
- Keep your child out of childcare and group play settings while sick with diarrhea, and follow the guidance of your local health department about returning your child to their childcare facility.
- Avoid taking your child swimming or to group water play venues until after they no longer have diarrhea.
- Have children and staff shower with soap before swimming.
- If a child is too young to shower independently, have staff wash the child, particularly the rear end, with soap and water.
- Take frequent bathroom breaks or check their diapers often.
- Change diapers in a diaper-changing area or bathroom and not by the water.
- Discourage children from getting the water in their mouths and swallowing it.
- Have children and staff shower with soap before swimming.