Skip to content
How It Works
Explore
Resources Ask a Question
Who It's For
Patients
Decode results, prep for appointments, weigh options.
Caregivers & advocates
Carry the research load for someone you love.
Providers & clinicians
Resources for patients in your practice.
Log In Ask a Question
PubMed This is a summary of 14 peer-reviewed journal articles Updated
Infectious Disease

Introduction to Shigellosis

At a Glance

Shigellosis is a highly contagious intestinal infection caused by Shigella bacteria, leading to severe, bloody diarrhea and abdominal cramps. It spreads easily through minor contact, but most people recover in five to seven days with proper hydration.

It is completely normal to feel a sense of panic when you or your child experience severe, bloody diarrhea and intense abdominal cramping. While these symptoms are distressing, understanding what is happening in your body can help you manage the situation. Shigellosis is a bacterial infection of the intestines caused by a group of bacteria called Shigella [1][2]. Although the symptoms can feel overwhelming, most healthy adults and children recover within five to seven days with proper rest and hydration [3].

Understanding the Scope of the Infection

Shigellosis is a significant public health concern both in the United States and globally. In the U.S. alone, the Centers for Disease Control and Prevention (CDC) estimates that there are approximately 450,000 to 500,000 cases of Shigella infection every year [3][4]. Because many people do not seek medical care or are not tested, the actual number of infections may be even higher [3]. The condition disproportionately affects children under age 5, making it a critical concern for parents and caregivers [5].

Why Shigella Spreads So Easily

One of the most striking features of Shigella is how little it takes to make you sick. For many other foodborne illnesses, a person might need to ingest thousands of bacteria to develop an infection. In contrast, Shigella has an exceptionally low infectious dose, meaning it takes as few as 10 to 100 individual bacteria to cause a full-blown illness [6][7].

This high level of contagiousness is why the infection spreads so rapidly through:

  • Direct Contact: Touching a surface or the hand of someone who is sick [2].
  • Contaminated Food or Water: Consuming items that have come into contact with even microscopic amounts of infected fecal matter [8].
  • Sexual Contact: Exposure during sexual activity, which is a recognized risk factor [9].

The Four Species of Shigella

There are four different species of Shigella bacteria. While they all cause similar symptoms, they vary in their prevalence and where they are most commonly found:

Species Characteristics
Shigella sonnei The most common species found in the United States and other developed nations [10]. It often causes a milder form of the illness [11].
Shigella flexneri Frequently found in developing countries and is a leading cause of the global burden of shigellosis [10].
Shigella boydii A rarer species that is typically restricted to specific geographic areas, such as the Indian subcontinent [3].
Shigella dysenteriae The most severe form, which can cause large-scale epidemics and produce the Shiga toxin, leading to more serious complications [3].

Managing the Emotional and Physical Stress

Finding blood in your stool (often called dysentery) is frightening, but it is a hallmark sign that the bacteria are affecting the lining of your intestines [12]. To stabilize yourself during this time:

  • Focus on Hydration: The most immediate danger of shigellosis is dehydration. Sip oral rehydration salts or clear liquids frequently, even if you do not feel thirsty [3].
  • Practice Strict Hygiene: To prevent spreading the infection to others, wash your hands with soap and water for at least 20 seconds after every bathroom visit or diaper change [2]. Note: Mechanical washing with soap and water is far more effective at removing Shigella than alcohol-based hand sanitizers.
  • Monitor Symptoms: While the illness is often self-limiting (meaning it resolves on its own), modern medicine has effective treatments if your doctor determines that antibiotics are necessary, especially if symptoms are severe or if you or your child are at high risk for complications [13][3].

Current medical guidelines emphasize that because multidrug resistance (when bacteria become immune to common antibiotics) is rising, antibiotics should be carefully managed by a professional who has evaluated your specific case [13][14].

Common questions in this guide

How long does a Shigellosis infection last?
Most healthy adults and children recover from a Shigella infection within five to seven days with proper rest and hydration. The illness is often self-limiting, meaning it typically resolves on its own.
Why is Shigella so contagious?
Shigella has an extremely low infectious dose, meaning it takes as few as 10 to 100 individual bacteria to cause a full-blown illness. It spreads rapidly through direct contact with an infected person, contaminated food or water, and sexual contact.
What is the best way to treat Shigellosis at home?
The most critical step in managing the infection is staying hydrated, as diarrhea can quickly lead to dehydration. Sip oral rehydration salts or clear liquids frequently, even if you do not feel thirsty.
How can I stop Shigellosis from spreading to my family?
Strict handwashing with soap and water for at least 20 seconds after every bathroom visit or diaper change is essential. Washing with soap and water is far more effective at removing Shigella bacteria than using alcohol-based hand sanitizers.
Can I take over-the-counter anti-diarrheal medicine?
You should avoid over-the-counter anti-diarrheal medications unless explicitly directed by your doctor. These medications can keep the bacteria in your system longer and potentially make your symptoms worse.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.Based on my symptoms, should I have a stool culture to confirm which species of Shigella I have?
  2. 2.Given the rise in antibiotic resistance, which specific antibiotic is currently most effective for Shigella in our local area?
  3. 3.What signs of dehydration should I watch for that would mean I need to go to the hospital?
  4. 4.How long after my symptoms stop am I still contagious, and when can I safely return to work or social activities?
  5. 5.Are there any over-the-counter medications, like anti-diarrheals, that I should avoid?

Questions For You

Tap a prompt to share your answer — we'll use it plus this page's context to start a tailored conversation.

References

References (14)
  1. 1

    Shigellosis in an Urban Slum in Kenya: Risk Factors and Antimicrobial Resistance.

    Ongadi BA, Aziz AB, Mbae CK, et al.

    Open forum infectious diseases 2025; (12(2)):ofaf026 doi:10.1093/ofid/ofaf026.

    PMID: 39963694
  2. 2

    Increased Severity of Multidrug-Resistant Shigella sonnei Infections in People Experiencing Homelessness.

    Stefanovic A, Alam ME, Matic N, et al.

    Clinical infectious diseases : an official publication of the Infectious Diseases Society of America 2025; (80(2)):339-346 doi:10.1093/cid/ciae575.

    PMID: 39570865
  3. 3

    Disparities in Shigellosis Incidence by Census Tract Poverty, Crowding, and Race/Ethnicity in the United States, FoodNet, 2004-2014.

    Libby T, Clogher P, Wilson E, et al.

    Open forum infectious diseases 2020; (7(2)):ofaa030 doi:10.1093/ofid/ofaa030.

    PMID: 32099844
  4. 4

    Elevated Risk for Antimicrobial Drug-Resistant Shigella Infection among Men Who Have Sex with Men, United States, 2011-2015.

    Bowen A, Grass J, Bicknese A, et al.

    Emerging infectious diseases 2016; (22(9)):1613-6 doi:10.3201/eid2209.160624.

    PMID: 27533624
  5. 5

    [Epidemiological characteristics of bacillary dysentery in China, 2005-2024].

    Zhang YF, Liu FF, Song Y, et al.

    Zhonghua liu xing bing xue za zhi = Zhonghua liuxingbingxue zazhi 2025; (46(6)):942-950 doi:10.3760/cma.j.cn112338-20250311-00153.

    PMID: 40518386
  6. 6

    Shigellaflexneri Regulator SlyA Controls Bacterial Acid Resistance by Directly Activating the Glutamate Decarboxylation System.

    Zhang B, Ran L, Wu M, et al.

    Frontiers in microbiology 2018; (9()):2071 doi:10.3389/fmicb.2018.02071.

    PMID: 30233544
  7. 7

    Immunization of Rabbits with a Quadrivalent Shigella Bioconjugate Vaccine Induces Functional Antibodies Reactive with Shigella Isolates from Kenya.

    Odundo EA, Weerts HP, Musila L, et al.

    mSphere 2022; (7(3)):e0102021 doi:10.1128/msphere.01020-21.

    PMID: 35611657
  8. 8

    Update on: Shigella new serogroups/serotypes and their antimicrobial resistance.

    Muthuirulandi Sethuvel DP, Devanga Ragupathi NK, Anandan S, Veeraraghavan B

    Letters in applied microbiology 2017; (64(1)):8-18 doi:10.1111/lam.12690.

    PMID: 27783408
  9. 9

    Burden and risk factors of Shigella sonnei shigellosis among children aged 0-59 months in hyperendemic communities in Israel.

    Cohen D, Korin H, Bassal R, et al.

    International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases 2019; (82()):117-123 doi:10.1016/j.ijid.2019.02.031.

    PMID: 30831222
  10. 10

    A review on Sero diversity and antimicrobial resistance patterns of Shigella species in Africa, Asia and South America, 2001-2014.

    Kahsay AG, Muthupandian S

    BMC research notes 2016; (9(1)):422 doi:10.1186/s13104-016-2236-7.

    PMID: 27576729
  11. 11

    Relation of childhood diarrheal morbidity with the type of tube well used and associated factors of Shigella sonnei diarrhea in rural Bangladesh site of the Global Enteric Multicenter Study.

    Jahan Y, Moriyama M, Hossain S, et al.

    Tropical medicine and health 2019; (47()):29 doi:10.1186/s41182-019-0158-5.

    PMID: 31073272
  12. 12

    Risk Factors of Seizure in Childhood Shigellosis.

    Mahyar A, Mahyar S, Oveisi S, et al.

    Iranian journal of child neurology 2024; (18(2)):43-53 doi:10.22037/ijcn.v18i2.43652.

    PMID: 38617397
  13. 13

    Emerging Ceftriaxone Resistance in Paediatric Shigella sonnei: A 10-Year Retrospective Study.

    Skripai A, Katz A, Lellouche J, et al.

    Acta paediatrica (Oslo, Norway : 1992) 2026; (115(5)):1063-1069 doi:10.1111/apa.70449.

    PMID: 41555678
  14. 14

    Genome and antibiotic resistance characteristics of Shigella clinical isolates in Fujian Province, Southeast China, 2005-2019.

    Huang M, Zhang X, Luo C, et al.

    Microbial genomics 2024; (10(11)) doi:10.1099/mgen.0.001325.

    PMID: 39565081

This page provides educational information about Shigellosis. If you or your child experience severe, bloody diarrhea or signs of dehydration, consult a healthcare provider immediately for an accurate diagnosis and treatment plan.

Get notified when new evidence is published on Shigellosis.

We monitor PubMed for new peer-reviewed studies on this topic and email a short summary when something meaningful changes.