What is the treatment for an adult or child with norovirus diarrhea lasting 10 days without severe underlying medical conditions?

Treatment of Norovirus Diarrhea Lasting 10 Days

For norovirus diarrhea persisting 10 days in adults or children without severe underlying conditions, treatment focuses exclusively on oral rehydration therapy and supportive care—antimicrobials are not indicated and should be avoided. 1, 2

Primary Treatment: Rehydration

Reduced osmolarity oral rehydration solution (ORS) is the cornerstone of treatment for norovirus gastroenteritis at any duration. 1, 2

ORS Administration Strategy

• Administer ORS as first-line therapy for mild to moderate dehydration in all age groups 1, 2
• Continue ORS until clinical dehydration is corrected (assess for thirst, orthostasis, decreased urination, dry mucous membranes) 2, 3
• Replace ongoing stool losses with ORS until diarrhea completely resolves 1, 2
• The WHO-recommended formulation contains Na 90 mM, K 20 mM, Cl 80 mM, HCO₃ 30 mM, and glucose 111 mM 3

Alternative Routes if Oral Intake Fails

• Consider nasogastric administration of ORS in patients with moderate dehydration who cannot tolerate oral intake 1, 2
• Reserve intravenous isotonic fluids (lactated Ringer's or normal saline) only for severe dehydration, shock, altered mental status, or ORS failure 1, 2, 3
• Once stabilized with IV fluids, transition back to ORS for remaining deficit replacement 1, 2

Nutritional Management

Resume age-appropriate diet immediately during or after rehydration—do not withhold food. 1, 2, 3

• Continue breastfeeding throughout the illness in infants and children 1, 2
• Early realimentation prevents malnutrition and may reduce stool output 4, 3

Why Antimicrobials Are NOT Indicated

Empiric antimicrobial therapy should be avoided in patients with persistent watery diarrhea lasting 10 days or more. 1

The guideline explicitly states that antimicrobials are not recommended for:

• Acute watery diarrhea without recent international travel 1, 2
• Persistent watery diarrhea (≥14 days duration) 1
• Viral gastroenteritis, which is self-limited and does not respond to antibiotics 2, 3

The only exceptions for antimicrobial consideration would be immunocompromised patients or ill-appearing young infants, but even then, only if bacterial superinfection is suspected 1, 2

Adjunctive Therapies

Probiotics

• May be offered to reduce symptom severity and duration in immunocompetent patients 1, 2
• Evidence is moderate quality, with potential reduction in diarrhea duration by approximately 25 hours 4

Antimotility Agents (Loperamide)

Antimotility drugs should NOT be given to children <18 years of age with acute diarrhea. 1, 2, 5

For adults:

• Loperamide may be considered in immunocompetent adults with watery diarrhea ONLY after adequate hydration 1, 2, 5
• Avoid loperamide if any bloody diarrhea, fever, or signs of inflammatory diarrhea are present due to risk of toxic megacolon 1, 2, 5
• Maximum daily dose is 16 mg (eight 2 mg capsules) 5

Antiemetics

• Ondansetron may be given to children >4 years and adolescents to facilitate oral rehydration when vomiting is present 1, 2

Special Considerations for Prolonged Norovirus

Norovirus typically causes symptoms lasting 24-48 hours, but symptoms persisting 10 days warrant consideration of:

• Immunocompromised status: Norovirus can cause chronic infection lasting months to years in immunocompromised patients, resulting in villous atrophy, severe malnutrition, and continuous viral shedding 6, 7
• Viral shedding: Even after symptom resolution, norovirus can shed in stool for a median of 19.5 days 8
• Non-infectious causes: If diarrhea persists beyond 14 days, consider inflammatory bowel disease, irritable bowel syndrome, or other non-infectious etiologies 2

Infection Control Measures

Hand hygiene is critical to prevent transmission, as norovirus is highly contagious. 4

• Wash hands with soap and water after using the toilet, before eating, and before food preparation 4
• Alcohol-based sanitizers are less effective against norovirus; soap and water is preferred 4
• Implement strict infection control measures in healthcare settings, especially in multi-bed rooms 8

Common Pitfalls to Avoid

• Do not prescribe antimicrobials for routine viral gastroenteritis—they provide no benefit and may cause harm 1, 2, 3
• Do not give antimotility agents to children or in cases of bloody/inflammatory diarrhea 1, 2, 5
• Do not withhold food during diarrheal episodes—continue age-appropriate diet 1, 2, 3
• Do not neglect rehydration while focusing on other therapies—ORS is the most important intervention 2, 3