Disease Description (Causes and Symptoms)
- Definition: Shigellosis is infectious colitis caused by bacteria of the genus Shigella. In Korea, it is classified as a Class 2 notifiable infectious disease.
- Causes and pathophysiology: It is transmitted orally through contaminated food or beverages, or through the feces of patients or carriers. Because the number of bacteria required for infection is very small (approximately 10–100), infection can occur with minimal exposure. The bacteria invade and multiply in the intestinal mucosa, causing mucoid and bloody diarrhea, mucosal damage, and inflammation.
- Environmental survival (reference): The bacteria can survive for extended periods in various media, including water for 2–6 weeks, milk and butter for 10–12 days, fruits and vegetables for 10 days, clothing for 1–3 weeks, and moist soil for several months.
- Incubation period and infectivity: The incubation period is 1–7 days. Infectivity lasts from the acute phase until the bacteria become negative in stool (usually within 4 weeks after onset), and some people may remain carriers for several months.
- Main symptoms: Fever, abdominal pain (cramping), nausea and vomiting, and diarrhea (initially watery, followed by a mixture of mucus and blood); children have an increased risk of seizures or dehydration. Most cases improve within 4–7 days, but severe complications may occur.
Treatment Methods (Standard Treatment, Precautions, and Management)
- Basic treatment
- Fluid and electrolyte replacement: Preventing and correcting dehydration is the highest priority (oral rehydration solution or intravenous fluids when necessary).
- Antibiotics: Used to shorten the duration of symptoms and the period of bacterial shedding. According to the evidence provided, first-line treatment is ciprofloxacin; ceftriaxone or azithromycin may be used as second-line treatment. The choice of antibiotic should be determined by considering local antibiotic susceptibility patterns and patient characteristics (age, pregnancy, and allergies).
- Hospitalization and isolation
- For infectious disease control, isolation treatment is recommended for patients. Food handlers, childcare workers, and patient-care workers should be excluded from work.
- Criteria for ending isolation: After diarrhea has stopped, 48 hours must have passed since discontinuation of antibiotics, and at least two consecutive stool tests collected at intervals of at least 24 hours must be negative for Shigella (applied according to public health guidelines).
- Self-care and precautions
- Practice thorough hand hygiene (soap and water), disinfect contaminated items, and keep personal belongings separate.
- Food preparation and service workers must not work until recovery has been confirmed.
- Because infants, older adults, and people with underlying conditions have a higher risk of dehydration, electrolyte imbalance, and complications, prompt medical care is recommended.
- Vaccine: There is currently no commercially available vaccine.
- Risk of complications: Hemolytic uremic syndrome (HUS), toxic megacolon, sepsis, and reactive arthritis (Reiter syndrome), among others.
Checklist Before an Outpatient Visit (Items to Bring, Reference Materials, and Example Questions)
- Items and records
- Record the date symptoms began and their course (number and characteristics of diarrheal stools: watery and/or containing blood or mucus), as well as the presence of fever or vomiting and symptoms of dehydration (dizziness, decreased urine output, and dry mouth)
- List of medications currently being taken (including recent antibiotics) and history of allergies
- Recent travel history (overseas or outbreak areas), exposure to group outbreaks (kindergartens, nursing facilities, prisons, etc.), whether you handle food, and whether you have had contact with a patient
- Results of tests already performed (such as stool culture and other test results) and photographs (including the date and time a stool sample was collected)
- Information to provide at the outpatient visit
- When symptoms began, treatments received (fluids and medications), and, for children, information about feeding and childcare, etc.
General Example Questions to Ask the Doctor
- "What tests do you recommend for my current condition, such as a stool culture? How long will the test results take?"
- "Which antibiotic do you recommend, and what are the expected treatment duration and possible side effects?"
- "What methods can I use at home to prevent and manage dehydration, and what criteria indicate that I should contact you immediately in an emergency?"
- "How long is the isolation period, and what are the criteria for returning to work (or a childcare facility)?"
Examples of Disease-Specific Questions
- "Should the choice of antibiotic be changed according to the local Shigella antibiotic susceptibility rate? When will the susceptibility test results be available?"
- "If I am a food handler (or a childcare or nursing worker), when can I return to work? What tests or symptom criteria are required before returning?"