What is the recommended treatment for acute dysentery, including rehydration and antibiotic therapy, in adults and children?

Treatment of Acute Dysentery

For acute dysentery (bloody diarrhea), empiric antibiotic therapy with azithromycin is the preferred first-line treatment in both adults and children, while simultaneously initiating oral rehydration therapy with reduced osmolarity ORS as the cornerstone of fluid management. 1, 2

Immediate Assessment and Rehydration

Evaluate Dehydration Severity

• Assess clinical signs systematically: skin turgor, mucous membrane moisture, mental status, capillary refill time, and vital signs to categorize dehydration as mild (3-5% deficit), moderate (6-9% deficit), or severe (≥10% deficit) 1, 2
• Acute weight change is the most accurate measure if baseline weight is available 2

Rehydration Protocol Based on Severity

For mild to moderate dehydration:

• Administer reduced osmolarity ORS (75-90 mEq/L sodium) as first-line therapy 1, 2
• Mild dehydration (3-5%): Give 50 mL/kg ORS over 2-4 hours 2
• Moderate dehydration (6-9%): Give 100 mL/kg ORS over 2-4 hours 1, 2
• Replace ongoing losses with 10 mL/kg ORS for each bloody stool and 2 mL/kg for each vomiting episode 2

For severe dehydration (≥10% deficit):

• Immediately initiate intravenous isotonic fluids (lactated Ringer's or normal saline) 1, 2
• Continue IV therapy until pulse, perfusion, and mental status normalize 1
• Transition to ORS to complete remaining fluid deficit once patient stabilizes 1

Special Technique for Vomiting Patients

• Administer 5-10 mL of ORS every 1-2 minutes using a spoon or syringe to prevent perpetuating vomiting 2
• Gradually increase volume as tolerance improves 2
• Consider nasogastric ORS administration if oral intake fails despite proper technique 1

Empiric Antibiotic Therapy for Dysentery

First-Line Antibiotic Choice

Azithromycin is the preferred empiric antibiotic for dysentery because of its effectiveness against the most common bacterial pathogens (Shigella, Salmonella, Campylobacter) and favorable resistance profile 3, 4:

Adults:

• Azithromycin 1000 mg single dose for febrile dysentery 3

Children:

• Azithromycin dosing based on local susceptibility patterns and travel history 1
• For infants <3 months with neurologic involvement, use third-generation cephalosporin instead 1

Alternative Antibiotics (When Azithromycin Unavailable)

• Fluoroquinolones (levofloxacin 500 mg once daily or ciprofloxacin 500 mg twice daily for 3 days) may be used in areas with high Shigella rates, but increasing resistance—particularly among Campylobacter—limits their utility 3
• Tailor antibiotic choice to susceptibility patterns from the region where infection was acquired 1

Critical Antibiotic Contraindication

Never administer antibiotics to patients with STEC O157 or other STEC producing Shiga toxin 2, as antimicrobial therapy increases risk of hemolytic uremic syndrome 1. This is a strong recommendation with moderate evidence.

Nutritional Management

• Continue breastfeeding throughout the illness without interruption in infants 1, 2
• Resume age-appropriate usual diet during or immediately after rehydration is completed 1, 2
• Recommended foods include starches, cereals, yogurt, fruits, and vegetables 2
• Avoid foods high in simple sugars and fats during acute phase 2

Medications to Avoid

Antimotility agents (loperamide) are absolutely contraindicated in dysentery:

• Never give to children <18 years of age with any acute diarrhea 1, 2
• Never give to adults with bloody diarrhea, as they can precipitate toxic megacolon and worsen outcomes 1

Special Populations Requiring Empiric Therapy

• Immunocompromised patients with severe illness and bloody diarrhea should receive empiric antibacterial treatment 1
• Patients with clinical features of sepsis suspected of having enteric fever require broad-spectrum antimicrobial therapy after culture collection 1

Diagnostic Considerations

• Obtain stool culture before initiating antibiotics when feasible, but do not delay treatment in severely ill patients 1
• A single fecal sample is the customary diagnostic approach 4
• Blood cultures are indicated if patient appears toxic or has signs of sepsis 1

Modification Based on Culture Results

Narrow or discontinue antimicrobial therapy when a clinically plausible organism is identified from diagnostic testing 1. This allows targeted therapy and reduces unnecessary antibiotic exposure.

Common Pitfalls to Avoid

• Do not delay rehydration while awaiting stool culture results—begin ORS immediately 2
• Do not use sports drinks, fruit juices, or soft drinks for rehydration, as they have insufficient sodium and excessive osmolality 2
• Do not give antibiotics empirically for non-bloody diarrhea in immunocompetent patients without travel history, as most cases are viral 1
• Do not treat asymptomatic contacts of patients with dysentery; instead, advise appropriate infection control measures 1

Infection Control Measures

• Practice rigorous hand hygiene after toilet use, diaper changes, before food preparation, and before eating 2
• Use gloves and gowns when caring for patients with dysentery 5
• Clean and disinfect contaminated surfaces promptly 5