Shigella infection (shigellosis)
Why in News?
Shigella infection (shigellosis) is an acute intestinal infection caused by Shigella bacteria, recently cases are rising and an increasing share of infections are antibiotic-resistant, including extensively drug-resistant (XDR) strains, making treatment more difficult.
What is Shigella?
- The Organism: It is a gram-negative, rod-shaped bacterium first isolated in 1897 by Japanese physician Kiyoshi Shiga.
- High Contagiousness: It has an incredibly low infectious dose—ingesting as few as 10 to 100 bacteria is enough to make a person severely ill.
- Human Reservoir: Humans are the primary natural reservoir for this bacterium.
How it Spreads? (Transmission)
- Fecal-Oral Route: The primary mode of transmission is the accidental ingestion of bacteria from the feces of an infected person.
- Contaminated Water & Food: Consuming water contaminated with sewage or eating food handled by an infected individual.
- Person-to-Person & Surfaces: Touching contaminated surfaces (bathroom door handles, flush levers, diapers) and then touching the mouth.
- Sexual Contact: Direct exposure during sexual activity, which is driving a significant portion of current adult outbreaks.
Common Symptoms
Symptoms usually appear 1 to 3 days after exposure and last for about a week:
Symptoms usually appear 1 to 3 days after exposure and last for about a week:
- Severe Diarrhea: Frequently prolonged, watery, and characteristically bloody or mucoid.
- Abdominal Cramps: Sharp, painful, and sudden stomach pain.
- Tenesmus: A constant, painful feeling of needing to pass stool even when the bowels are completely empty.
- High Fever & Vomiting: Sudden spikes in temperature (sometimes triggering seizures in children) accompanied by nausea.
High-Risk Groups
- Children under 5 years old: Especially those in daycare settings, due to developing immune systems and shared play environments.
- People in crowded housing: Areas with poor sanitation, refugee camps, or individuals experiencing homelessness.
- Men who have sex with men (MSM): Due to specific rapid transmission paths within sexual networks.
- International travellers: Individuals visiting developing nations with sub-optimal water infrastructure.
Treatment & Management
- Hydration First: The vast majority of mild cases clear spontaneously in 5 to 7 days. Treatment focuses primarily on oral rehydration solutions (ORS) and electrolyte replenishment.
- Antibiotics: Reserved for severe cases, the elderly, or immunocompromised patients. Due to growing Antimicrobial Resistance (AMR), doctors now rely strictly on laboratory-guided antibiotic selection.
- Avoid Anti-Diarrheal Medications: Medicines like loperamide (Imodium) should not be taken, as they keep the bacteria trapped in the digestive tract longer, worsening the infection.
Prevention Strategies
- Rigorous Handwashing: Wash hands thoroughly with soap and water for at least 20 seconds, especially after using the toilet or changing diapers.
- Safe Food & Water Practices: Boil water or drink bottled water if the local supply is questionable, and wash fruits and vegetables aggressively.
- Sanitation Separation: Safely dispose of soiled diapers in lined, lidded bins.
- Post-Recovery Caution: Infected individuals can shed the bacteria in their stool for weeks after symptoms disappear. Partners should avoid sexual activity for at least a week after full clinical recovery.
