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Overview

What Is Shigellosis?

Shigellosis is an infection of the intestines caused by Shigella bacteria. It commonly causes diarrhea, stomach cramps, fever, and sometimes bloody stools. The infection spreads easily through very small amounts of contaminated stool. Children, travelers, and people in childcare, household, or other group settings may be especially affected.

Symptoms

Shigellosis Symptoms

Shigellosis symptoms often begin within several days after exposure. Illness can be mild, but some people develop more severe symptoms that require medical care.

  • Diarrhea may be frequent and watery.
  • Bloody or mucous stools may occur when the intestine becomes inflamed.
  • Fever is a common sign of shigellosis.
  • Stomach cramps or abdominal pain may develop.
  • Nausea can occur with or without other digestive symptoms.
  • Vomiting may make it harder to replace lost fluids.
  • Dehydration can cause thirst, dry mouth, dizziness, or reduced urination.

How It Spreads

How Shigellosis Spreads

Shigella spreads when microscopic amounts of stool enter another person’s mouth. This can happen through contaminated hands, food, water, surfaces, or sexual contact, making shigellosis infection particularly easy to pass between people.

  • Childcare settings can allow germs to spread through diaper changes, shared objects, and close contact.
  • Household contact with someone who has diarrhea can increase exposure.
  • Travel to places with limited access to safe water or sanitation can increase risk.
  • Shared food can become contaminated when an infected person handles it.
  • Contaminated recreational water can spread Shigella if it is swallowed.
  • Sexual activity involving anal contact can spread Shigella through contact with stool.

Important transmission guidance

Shigella can spread after symptoms improve

A person may remain contagious after diarrhea and other symptoms improve. Follow clinician or public-health guidance about hand hygiene, food handling, work, school, childcare, swimming, and sexual activity.

Risk Factors

Shigellosis Risk Factors

  • Childcare attendance or caring for young children can increase exposure to Shigella.
  • Travel to areas with limited sanitation or unsafe food and water can increase infection risk.
  • Crowded living conditions can make person-to-person spread more likely.
  • Contact with contaminated water, food, hands, or surfaces can lead to infection.
  • Sexual contact involving anal exposure can increase the risk of transmission.
  • Young children may have a higher risk of complications from infection.
  • A weakened immune system can increase the risk of severe or prolonged illness.

Handwashing, safe food and water practices, and avoiding contact that could spread stool are modifiable prevention steps. Age and some medical conditions cannot be changed, but people with these factors can seek advice early if symptoms develop.

Complications

Shigellosis Complications

  • Dehydration can develop when diarrhea and vomiting cause substantial fluid loss.
  • Seizures may rarely occur in young children with a high fever.
  • Hemolytic uremic syndrome can rarely affect the blood and kidneys, particularly after certain bacterial infections.
  • Toxic megacolon is a rare, severe widening of the colon that requires urgent treatment.
  • Bloodstream infection can occur rarely, especially in people with weakened immune systems.
  • Reactive arthritis can cause joint pain or inflammation after the infection.
  • Post-infectious bowel symptoms may include ongoing changes in bowel habits after the infection clears.

Diagnosis

How Shigellosis Is Diagnosed

Diagnosis is based on the symptom pattern, exposure history, physical examination, and laboratory testing rather than symptoms alone. A clinician may ask about travel, sick contacts, group settings, food and water exposure, and sexual contact.

  • A stool culture can grow Shigella from a stool sample and help confirm infection.
  • Molecular stool testing can detect Shigella genetic material.
  • Antibiotic susceptibility testing may be used when antibiotics are being considered or resistance is a concern.
  • A clinician may assess hydration and look for signs of complications during the examination.

Treatment & Management

Shigellosis Treatment and Management

  • Drink oral rehydration fluids to replace water and important salts lost through diarrhea.
  • Continue age-appropriate nutrition as tolerated unless a clinician advises otherwise.
  • Rest while the body recovers from the infection.
  • Significant dehydration may require medical treatment, including fluids given in a healthcare setting.

Use medicines carefully

Treatment should be clinician-directed

Antibiotics are prescribed selectively based on illness severity, the person’s risk factors, local resistance patterns, and test results. Do not use leftover antibiotics or anti-diarrheal medicines such as loperamide without medical guidance, because they may be unsuitable in some cases.

Prevention

Preventing Shigellosis

  • Wash your hands thoroughly with soap and water after using the toilet, changing a diaper, and before preparing or eating food.
  • Change diapers safely and clean the changing area and your hands afterward.
  • Do not prepare food for other people while ill and follow public-health advice about when to resume.
  • Use safe food and water, especially when traveling.
  • Clean and disinfect surfaces that may be contaminated with stool.
  • Avoid swimming while ill and follow local guidance about when it is safe to return.
  • Use barriers during sexual activity and avoid sexual contact that could involve stool while recovering.

Outlook and Prognosis

Shigellosis Outlook and Prognosis

Many people recover within about a week with appropriate fluids and care. Recovery may take longer in severe illness or in people with higher-risk medical conditions.

  • Temporary changes in bowel habits may continue for a short time after other symptoms improve.
  • Post-infectious complications such as reactive arthritis or ongoing bowel symptoms can occur but are not typical for everyone.
  • Shigella may continue to be shed after symptoms improve, so a person can still spread the infection.
  • Follow guidance about returning to work, school, childcare, swimming, or sexual activity.

When Should You See a Doctor

When Should You See a Doctor for Shigellosis?

  • Contact a healthcare professional for bloody diarrhea.
  • Seek medical advice for a high or persistent fever.
  • Severe abdominal pain warrants prompt evaluation.
  • Ongoing vomiting can prevent adequate fluid replacement and should be assessed.
  • Contact a clinician for symptoms of dehydration, such as dizziness, dry mouth, or reduced urination.
  • Diarrhea lasting several days should be discussed with a healthcare professional.
  • Illness in an infant or older adult may require earlier medical advice.
  • People with weakened immunity should contact a clinician promptly when symptoms develop.
  • Recent travel may be important information for a clinician evaluating shigellosis symptoms.
  • Suspected exposure in a childcare, household, or other group setting may require medical and public-health guidance.

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